Saturday, December 17, 2011

Red Meat and Your Health

      This article is long overdue.  I've touched on red meat before, and whether or not it contributes to chronic diseases like coronary heart disease, diabetes, and cancer, but I've been meaning to do a more comprehensive write-up on it.  It's time to drive a stake right through the heart of this whole red meat = death hypothesis, because to be honest the idea is completely absurd.  I think you'll be amazed at how easily this myth falls; it doesn't take much when it's built like a straw house, just ask the Three Little Pigs.  And hopefully then we can all stop poo-pooing on red meat and enjoy a steak.

Firstly, let's clarify something... no one has ever proven that red meat causes heart disease, diabetes, cancer, or any other chronic disease.  In fact, there hasn't been a single randomized, clinical trial conducted on the subject.  The best we can say for sure is that red meat is associated with all of these diseases.   In other words, people who consume more red meat tend to have an increased chance of developing these problems.  I'm not arguing that fact.  Many studies have demonstrated this association and it is a relatively consistent finding.  What I am arguing, however, is that there are several key factors that explain this common link between red meat and chronic disease, and none of them involve red meat being inherently deadly.  Prepare yourself for a series of truth bombs...

Monday, November 21, 2011

My Thoughts On Obesity

The other day in one of my classes, we began a "Weight Management" unit, which is one of my favorite aspects of nutrition.  Despite the fact that I've never had a weight problem, I find it fascinating learning about what makes people gain weight and how to lose it.  But I was quickly reminded how much I completely disagree with the conventional model.  Or maybe I'm being nice... let me rephrase that.  The conventional model is completely wrong.  Allow me to explain myself...

The conventional model of obesity is as follows:  Eat more calories than you expend and you'll gain weight.  To paraphrase my professor, it really is just a simple math equation.  And for weight loss, burn more calories than you take in and you'll lose weight. That's not the part I disagree with.  That is an established fact.  But the problem is that conventional obesity paradigm ends there.  Really?? That's it?? I'm paying for a top quality nutrition education, and we're not going to delve any deeper than that?  I would expect this in a high school health class; you don't need to bother high schoolers with the finer details that they likely wouldn't even care about.  But this is an advanced course in nutrition... I expect more than the "all you need to lose weight is a calculator" mentality.

This calories in, calories out model of obesity says that if you've gained weight, you've consumed more calories than you've burned, but it does nothing to explain why someone has consumed more than they've burned.  Imagine walking into a room full of people.  You ask someone, "Why are there so many people in this room?"  And the response you get is, "Because more people entered the room than left it."  That would be a stupid answer, something a 2nd grader might tell you when they first learn about addition and subtraction.  But that is essentially the same as telling someone they got fat because they consumed more calories than they expended.  It's obvious, but it doesn't really tell us anything about why that is the case.  While excess caloric intake causes obesity, you can go much deeper than that (that's what she said).

Tuesday, November 8, 2011

New Study: Low Cholesterol More Deadly Than High Cholesterol

I hate to say I told you so.  But I did.  Like a million times.  Yet, the fear of cholesterol continues.  What is it?  Is it the Lipitor ads?  Is it your cholesterol-phobic doctor, determined to get your cholesterol under 200 mg/dl at all cost?  Whatever it is, it's about time we stopped worrying so damn much about high cholesterol.  This new study, entitled "Is the use of cholesterol in mortality risk algorithms in clinical guidelines valid?  Ten years prospective data from the Norwegian HUNT 2 study.", shows us why.  Did anybody hear anything about this one in the media??  I didn't think so, not with a catchy title like that.  At least now the 3 people that read my blog will be aware of it.  The researchers followed 52,087 Norwegians aged 20-74 who were free of cardiovascular disease (CVD) for 10 years, then assessed the relationship of total cholesterol with total mortality, CVD mortality, and ischemic heart disease mortality (IHD).  (Just to be clear, CVD mortality signifies deaths from any disease of the cardiovascular system, while ischemic heart disease refers only to diseases involving restricted blood flow to the heart.)  Let's jump straight into the data then, shall we?  And another note:  since this study comes from Europe, the units for blood cholesterol are shown in mmol/L, rather than the mg/dL that we are used to.  The researchers classified the participants into four groups, based on their blood cholesterol.  Here are the converted unit values in mg/dL for the four groups...  <193, 193-229, 230-269, and >270

First, the least shocking data.  This graph compares the association between cholesterol levels and death from ischemic heart disease.  For the men, it looks like there's not much variation.  Deaths from heart disease rose slightly along with cholesterol levels, but nothing dramatic.  Women, on the other hand, yielded a much more interesting result.  Clearly, by a LARGE margin, cholesterol below 193 mg/dL was most predictive of death from heart disease.  All other groups, including the group with cholesterol over 270 mg/dL, showed significantly lower risk.  Yes, seriously.  On to the next graph!

Monday, October 10, 2011

Why Stomach Acid Actually Prevents Heartburn

GERD (gastroesophageal reflux disease), or heartburn as it's commonly known, is the most common digestive disorder in the United States; approximately 10-20% of Americans experience symptoms at least once a week.  Conventional treatment is to take antacids.... chances are you've probably used these drugs at one time or another.  Tums, Zantac, Pepcid... ring any bells?  Or if you're really serious about your heartburn, maybe prescription Nexium?  Drug stores sell these things like candy.  Literally.  Tums is placed right next to the candy and gum in the checkout area, and for the first ten or so years of my life, I thought it was candy.  On the prescription side, Nexium was the number two best selling prescription drug on the market in 2006, just behind Lipitor (don't even get me started), bringing in $5.1 billion.  People generally find heartburn relief in these medications, so all is well right?  Not quite.

Although this topic may seem tame, there is more than you know going on behind the scenes.  I recently read a fantastic set of articles by Chris Kresser about the physiology and treatment of GERD that brought this to my attention.  It's a long six-part series, something I probably wouldn't have made time for if not for the combination of my iPhone and a boring afternoon class.  Since I will be summarizing a large amount of material here and simplifying some of the concepts, it would be unrealistic for me to cite all of my claims like Chris did.  So if you don't believe me, just refer to the link above.

For starters, let's talk about what exactly GERD is.  Out of Taber's Medical Dictionary, GERD is:  "A common condition in which acid from the stomach flows back into the esophagus, causing discomfort and, in some instances, damage to the esophageal lining."  You see, there is a one-way door between the esophagus and the stomach called the lower esophageal sphincter.  In digestion, food moves through this door to the stomach, and when everything is functioning correctly, nothing comes back up.  In GERD, small amounts of stomach acid are able to creep up into the esophagus, causing burning and damage to the wall of the esophagus, which can lead to a number of problems including esophageal cancer if left untreated.

Sunday, September 11, 2011

Poking Fun at the Lipid Hypothesis

Quick one today about saturated fat and cholesterol.  If you haven't noticed, I really get my jollies off by poking fun at the lipid hypothesis.

Ancel Keys, the man largely responsible for convincing everyone that saturated fat clogs your arteries and gives you heart disease, published a few observational studies on the subject in the 1950's.  While his data showed a clear association between a high fat intake and increased risk of heart disease, the studies were extremely flawed.  Keys essentially cherry-picked the data from certain countries that would support his idea.  See this for a full explanation.

So, I thought I would share with you today some other, more convincing data on saturated fat consumption and heart disease death risk.  The following tables were assembled by Dr. Malcolm Kendrick, using the 1998 data from the World Health Organization.  He sorted through all of the data on European countries and found the seven countries with the lowest consumption of saturated fat, along with the seven countries with the highest consumption of saturated fat, and compared their death rates from heart disease. 

Here are the seven countries consuming the least saturated fat:

And here is the data on the seven consuming the most saturated fat:

At first glance, you may do a double take.  But your eyes are not deceiving you... the countries consuming more saturated fat are suffering fewer deaths from heart disease.  The country consuming the most saturated fat, France, consumes approximately three times more than the country at the opposite end of the spectrum, Georgia, but at least six times more Georgians die of heart disease.  These numbers are not made up guys.  This is real.  In fact, every single one of the seven countries with the lowest saturated fat consumption has significantly higher rates of heart disease than every single one of the seven countries with the highest saturated fat consumption.  Now, explain to me again how saturated fat causes heart disease...

Saturday, August 6, 2011

Grass-Fed Beef vs. Grain-Fed Beef

The popularity of grass-fed beef has been on the rise lately, thanks in large part to the various pieces of media that are exposing the horrors of conventional meat production.  In my case, it was the film Food Inc. and Michael Pollan's outstanding book The Omnivore's Dilemma that brought the issue to my attention.  For those of you who don't know what I'm talking about when I say "grass-fed beef", here's a brief explanation:  Cattle have evolved over time to eat grass.  They get all the nutrition they need from grass alone.  However, in modern beef production, cattle are fed a diet of mostly corn and other grains, which can cause all sorts of health problems, but it fattens them much more quickly and increases production.  While this allows farmers to produce more beef faster, the whole process is extremely wasteful and destructive to the environment.  And although the price on the beef you see in the supermarket is affordable, this does not in any way reflect the true cost of that beef.  When you factor in all the corn grown specifically to raise the cattle, the antibiotics needed to keep them in decent health, and the environmental problems, just to name a few of the costs, the actual price of that beef looks a little different.  The only reason it's available to consumers at such a low price is because of government subsidies.  As a result of all of this, an increasing number of people are opting to seek out grass-fed beef, meaning that the cows only eat grass and are allowed to graze in fields as they please.  This type of beef production is healthier for the cattle, better for the environment, and is a much lower-input process overall.  In addition to the philosophical reasons to choose grass-fed beef, though, there are a number of nutritional benefits as well, and that will be my main focus for today.

Tuesday, July 12, 2011

Do Cholesterol-Lowering Drugs Save Lives?

If you read my last post about cholesterol-lowering drugs, then you understand some of the problems that can arise from their use.  Statins can produce some nasty side effects.  But side effects aside, statins save lives right?  I mean, doctors prescribe them to just about everyone, they must be effective.  Not quite... the story is not as simple as it may seem.

When looking at the statin drug clinical trials, it's important to keep a few things in mind.  Firstly, and most importantly... total mortality is more important than heart disease mortality.  If a drug prevents you from dying of heart disease but doesn't affect your chances of dying in general, then that drug is not worth taking.  What's most important is whether or not the drug will extend your life.  Secondly, you must consider that different groups of people may respond differently to the drug.  Women, middle-aged men, the elderly, and those with preexisting heart disease may all respond differently to treatment. 

I'd like to begin by talking about women... both because I like women, and because they don't respond well to statins.  Although many statin studies notoriously neglect to reveal the all-cause death data for women, there are a few studies that do.  Check out the Scandinavian Simvastatin Survivial Study (4S), which was one of the most positive trials to date.  The big pharma folks must have been partying it up when this one came out.  This was a secondary prevention trial, meaning that participants all had pre-existing heart disease (previous heart attack or angina).  For future reference, a primary prevention trial would be an experiment in which the participants did not have pre-existing heart disease.  So, half of them took simvastatin and half of them took a placebo.  The results were great across the board: heart attack numbers were reduced, along with deaths from heart disease and all-cause mortality.  But there was one group that clearly didn't benefit:  women.  Over the duration of the 5.4 years of the trial, 27 (6.6%) of the women taking the statin died, while only 25 (6%) of the women taking the placebo died.  So despite the rest of the data, which was very supportive of statins, there was actually a slight increased risk of death in women from taking the statin.  As you'll soon see, this finding is consistent throughout all of the statin trials, yet it is completely ignored by mainstream medicine.  These drugs simply don't work for women.

Monday, June 6, 2011

The Potential Dangers of Cholesterol-Lowering Drugs

In recent years, the prescription of statin drugs to reduce cholesterol has soared through the roof.  You've heard of them:  Lipitor (atorvastatin), Crestor (rosuvastatin), Zocor (simvastatin), and the like. The supposed benefits of these drugs, as your doctor will tell you, is that they'll reduce your cholesterol levels, hence lowering your risk of heart disease.  I'm sure you all know by now how I feel about lowering cholesterol levels (see this)... but that's beside the point in today's discussion.  I will just say that statin drugs' effectiveness may have been a bit overstated.  Today, though, I'd like to focus on the dangers, or side effects, one may encounter in taking statins.

First, just a little information about how statin drugs work in the body.  Their main function is to block an enzyme called HMG CoA Reductase.  This is one of the enzymes that is involved in making cholesterol in the liver.  So through blocking this pathway, the drug has inhibited the body's ability to make cholesterol molecules.  As a result, your blood cholesterol level goes down, your doctor is happy, and you're happy.  We've finally won the battle against cholesterol!  Yeah... except cholesterol is needed in the body for all sorts of vital processes, like hormone production, vitamin D synthesis, cell membrane structure, and brain function, just to name a few.  Hopefully by the end of this, you'll realize how ridiculous it is to think that blocking an important biochemical pathway like this one is a good idea.

Wednesday, May 25, 2011

Why Low-Carb Diets Work

NOTE: This post is outdated.  I no longer believe everything I have written in this article.  I'll keep it up regardless, but it does not accurately reflect my current thinking.

Although it may seem counter-intuitive, a diet low in carbohydrates, which by definition is also higher in fat, may be the most effective way to lose weight.  I remember when I first heard of the Atkins Diet back in high school, when I saw my friend's father take the cheese off of a piece of pizza and throw away the bread.  Surely you can't lose weight by eating fatty cheese and throwing out the low-fat bread!  But while it made little sense to me at the time, low-carbohydrate diets really do work, and the science supporting this concept is just about indisputable.

Firstly, I would like to state that in weight-loss, what most people are concerned about is losing fat, as opposed to just weight in general.  Fat is the enemy, not muscle; we want to keep our muscle.  As a result, I'll be discussing how the fat tissue is regulated in the body.  In order to understand how low-carb diets help you lose fat, it is important to understand the function of two key enzymes that regulate the fat tissue:  lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL).  The activity of both of these enzymes is controlled by the hormone insulin, which is secreted in response to carbohydrate consumption.  I'm going to get into some biochemistry here... I like biochemistry because, since most people don't understand it, I can make it look like I really know what I'm talking about, even though in reality I'm just making up words and hoping I don't get caught.  Seriously though, it's important to understand a little basic biochemistry in order to truly understand how a low-carb diet burns fat like nothing else.

Sunday, May 15, 2011

Why Low-Calorie, Low-Fat Diets Don't Work

NOTE: This post is outdated.  I no longer believe everything I have written in this article.  I'll keep it up regardless, but it does not accurately reflect my current thinking. 

Losing weight isn't easy.  Just ask your neighborhood middle-aged yo-yo dieter.  It's hard to get the weight off, and it's even harder to keep it off.  But the problem, in my opinion, does not lie in a lack of motivation or drive to make a successful lifestyle change.  The problem is that the vast majority of dieters are going about it the wrong way.  The media loves to promote this simple calories in, calories out model of weight loss, and while calories certainly do count for something, there's much more to the story.  What the calories in, calories out concept fails to account for is what your body actually does with the calories it receives, and it turns out that is a vitally important concept in weight loss. 

First off, let's discuss what happens when you try to lose weight by simply eating less (also known as starving yourself).  You start off with all the motivation in the world, probably counting calories and planning out all of your meals.  Let's say you aim to eat 1500 calories a day, and your body wants to burn 2500.  At this rate, according to the simple math of the calories in, calories out model, you should be losing about 2 pounds per week.  And indeed, you'll probably lose a few pounds in the first few weeks on a diet like this.  But you're setting yourself up for failure in the long-term.  Here's why.

Saturday, April 23, 2011

5 Fake Health Foods

When people decide to "go on a diet", there are a number of so-called healthy foods that they typically turn to.  Some may be healthy, others simply are not.  But inevitably there are a few myths out there that just won't die, thanks in large part to clever advertising and labeling.  Heck, all food manufacturers have to do to convince people their product is healthy is to slap an "All Natural" or "Low in Fat" label on it.  Here is a short list of 5 of these "healthy" or "weight-loss" foods that dieters typically turn to and why they're not all they're cracked up to be. 

1.  Veggie Burgers
Ohhh veggie burgers... if I had a nickel for every time I've seen a health-conscious, well-intentioned dieter opt for a veggie burger instead of a real one... well I'd probably have about $10.  But that's a lot of nickels.  Veggie burgers are absolutely not a healthy alternative to beef burgers.  If you look up the ingredients of a typical veggie burger, like the Morningstar Farms Grillers Original burger, you'll learn that these things consist of largely soy and other isolated vegetable proteins.  This is a problem.  Soy is not a health food, especially when it's undergone as much processing as the soy in these burgers has.  There are too many risks of soy to fully explore here, but just to name a few...  1. Soy phytoestrogens disrupt endocrine function and have the potential to cause infertility and to promote breast cancer in adult women.  2. Soy phytoestrogens are potent antithyroid agents that cause hypothyroidism and may cause thyroid cancer.  3. In infants, consumption of soy formula has been linked to autoimmune thyroid disease.  4. Free glutamic acid or MSG, a potent neurotoxin, is formed during soy food processing and additional amounts are added to many soy foods.  Check out the Weston A. Price Foundation for more of this information.  Soy is not good for you, and veggie burgers are made up almost entirely of ingredients made in a food science lab.  Not a good choice.  Just eat a real burger.

Friday, April 15, 2011

Historical Context, Part 6 - The Obesity Epidemic

As I've talked about in previous posts, the government began making dietary recommendations in 1977, beginning with Senator George McGovern's Dietary Goals for the United States.  The torch was then passed to the USDA in 1980, which began drafting dietary recommendations every five years.  The most recent USDA Dietary Guidelines for Americans came out at the end of 2010.  For all intents and purposes, the recommendations have changed very little since 1977.  Let's look at some of the specifics of the government's advice here, and we'll see if Americans have been following it over the past few decades.  First on the list, avoid foods high in saturated fat.  This includes eggs (which everyone has been afraid of since that Time magazine article), red meat, and full-fat dairy.  And when you cut something out of your diet, you have to replace it with something else, right?  The government advised that we eat more starches, grains, and vegetable oils in the place of these high-saturated fat foods, along with more low-fat meats like chicken and fish.  Well, it turns out that Americans have been following this advice. Here are a few graphs showing the recent dietary trends:

Since the 1970's, we have done exactly what was recommended for us to do.  We've eaten fewer eggs, and keep in mind also that the egg data does not take into account the countless yolks that are thrown away for fear of their artery-clogging capabilities.  Until recently, an egg white omelet was a stupid idea, and rightfully so; it tastes awful.  We've reduced red meat consumption and replaced it with chicken and fish.  Red meat has become a poster boy for our health problems, but its consumption has declined as Americans' health has deteriorated over the past few decades.  Whole milk consumption has declined immensely.  Americans drink only about 1/3 of the whole milk that they did in 1970.  It appears as though most Americans have switched over to low-fat or fat-free milk, which have both increased dramatically over the same time period.  And then we come to grains, flour, sugar, and vegetable oil.  All three of these have been on the rise in the American diet over the past few decades.  Remember, the Dietary Guidelines recommended that we increase our grain consumption, and we did just that.  Unfortunately, in our attempt to avoid animal fat, we also consumed more sugar.  Sugar was something that was not stressed in the early Dietary Guidelines, but more recently the USDA has begun to recommend reducing sugar intake.  As for vegetable oil, I could not find a graph showing its consumption, but since it didn't exist before the mid 20th century and now it's considered an essential cooking item, it's safe to assume its consumption has increased exponentially. 

So... we followed the advice that was provided to us.  We ate less red meat and saturated-fat-laden foods.  We ate more grains and flour products.  We chose low-fat protein sources like skim milk and chicken breast, and we cooked with vegetable oils.  Well, here's what happened:

Obesity gone wild.   The first graph is from 1985, which was the first year obesity statistics by state were recorded.  In 1985, no state had an obesity rate over 14%.  Actually, data wasn't available for every state, but West Virginia, which has the highest obesity rate today, was under 14% in 1985, so chances are that was just about the highest in the country.  In 2009, only Colorado had an obesity rate under 19%, and there were 9 states with an obesity rate over 30%.  You could say, based on these numbers, that the obesity rate in America has approximately doubled since 1985, maybe even more than doubled.

But don't say it's because we're eating too much red meat and saturated fat, because we aren't.  Grains, sugar, and other carbohydrates are the foods that have been on the rise in America during this period in which obesity took off.  Besides, we have been eating red meat and saturated-fat-containing foods for millions of years.  The obesity epidemic, and the heart disease epidemic for that matter, only began in the 20th century.  As Sean Croxton of Underground Wellness always says, you can't blame new diseases on old foods.  I agree completely.  The culprits here are not red meat and eggs.  It is our overconsumption of grains, flour, sugar, and vegetable oils that is at the core of our health problems.

But what about the heart disease epidemic?  Did the recent dietary change prevent heart attacks?  It actually may have.  Heart disease rates have leveled off since the mid 1970's (see graph below).  Of course, there are other factors involved here, like the fact that everyone and their mother is on statin drugs, which may help prevent heart disease.  I'm not sold on statins at all, but there is some evidence that it's probably helping a few people prevent heart disease deaths.  It is important to note, though, that we are only talking about heart disease deaths.  Is a diet that can reduce your risk for heart disease, but increase your waistline and make your more susceptible to cancer, really the ideal diet?  I don't think so....

Now here we are in 2011.  The newest Dietary Guidelines have just been released, and we've still got a food pyramid that is based on a nutrient-poor food (grains) that hasn't been consumed for 99% of human history.  But what else is our government to do?  We as humans made a decision 10,000 years ago to commit to a grain-based diet when we adopted agriculture as our means for food production.  We sacrificed our health in return for the ability to support a greater population.  As a result, our modern government is obligated to support a diet that can feed the ever-increasing population; a diet based on grains that are high in calories and can be mass-produced fairly easily and inexpensively.  The USDA Dietary Guidelines will NEVER adopt a lower carb Paleo Diet mindset, regardless of how clear the science is.  Firstly, such a stark change in ideals would admit that they've been wrong for the past three decades.  Secondly, it would ruin the agricultural industry.  Thirdly, eating an optimal human diet is just not possible for everyone to do with our current population.  Like I said, we made the decision to eat a grain-based diet when we decided to adopt agriculture. 

So, to conclude this six-part Historical Context series, THIS is why I reject the low-fat concept, THIS is why I think the Dietary Guidelines are ridiculous, and THIS is why I eat the way I do.  I hope my position is more clear now.  Thank you and goodnight.

Saturday, March 26, 2011

Historical Context, Part 5 - Inadequate Evidence

Following in the McGovern Senate Select Committee's lead, the USDA drafted its first official Dietary Guidelines for Americans in 1980.  The recommendations were strikingly similar to those of McGovern's recommendations, despite the fact that many of the organizations involved in food and nutrition, like the Food and Drug Administration (FDA), the National Academy of Sciences (NAS), and the National Institute of Health (NIH), had considered the original Dietary Goals to be largely a political document instead of a scientific one.  Now, solid scientific evidence was needed to support the low-fat diets they were promoting (that's a little backwards, no?).  In the early 70's, NIH administrators decided against conducting a $1 billion clinical trial that would likely offer a definitive answer to whether or not low-fat diets prolong life.  Instead, they opted to conduct a half-dozen smaller observational studies, at a third of the cost, that they hoped would provide the evidence they were looking for.  The results of these studies were published between 1980 and 1984.

Four of these studies tried to establish relationships between dietary fat and heart disease.  They observed populations in Honolulu, Puerto Rico, Chicago, and Framingham, Massachusetts, and although some of the data suggested an association with fat and heart disease, the data involving all-cause death revealed a different story.  In the Honolulu study, the researchers followed 7,300 men of Japanese descent and found that those who developed heart disease ate slightly more fat and saturated fat than those who didn't.  However, the men who actually died tended to eat less fat and less saturated fat, so low-fat diets were associated with increased mortality.  Similar results were seen in Framingham and Puerto Rico.  The researchers' interpretation of these results is absolutely astounding.  They reported that because men in Puerto Rico and Honolulu who remained free of heart disease ate more starch, the studies suggest that Americans should follow the Dietary Guidelines and eat more starch.  Consequently, in order to avoid eating too many calories, Americans should also reduce fat intake.  WHAT??  Talk about twisting the results to support your hypothesis...

And it gets worse.  Also found in this data, with the exception of the Chicago study, was an association between cholesterol levels and cancer rates.  That is, low cholesterol predicts higher cancer rates.  This link was not abnormal.  In fact, by 1980, this association was showing up regularly in studies like this.  But this connection seemed to present a problem for the diet-heart hypothesis and was never publicized the way it should have been.  Just ask someone on the street today if they've ever heard that high cholesterol may be protective of cancer... they'll probably laugh and walk away.  Regardless, there is a strong link there.  In the Framingham study, men whose total cholesterol was below 190 mg/dl were three times more likely to get colon cancer as men with cholesterol over 220 mg/dl, and they were almost twice as likely to get any form of cancer than those with cholesterol over 280 mg/dl.  This is not an anomaly.  It is in fact very typical of these types of studies.  Those who have higher cholesterol tend to have a slightly greater risk of heart disease, but those with lower cholesterol clearly have a greater risk of cancer, and often times a greater total mortality rate as well.

The National Heart, Lung, and Blood Institute (NHLBI) also published two studies in the early 1980's that were supposed to provide support for the diet-heart hypothesis.  The first was the Multiple Risk Factor Intervention Trial (MRFIT), which collected a group of 12,000 men who were considered at imminent risk of having a heart attack; they all had a total cholesterol level over 290 mg/dl.  The men were randomly divided into two groups, a control group and an intervention group.  The control group was told to live, eat, and address their health problems however they wanted, while the intervention group was counseled to quit smoking, take medication to control their high blood pressure, and eat a low-fat, low-cholesterol diet.  The men were then followed for 7 years.  The results, announced in October 1982, showed that there had been slightly more deaths in the intervention group than in the control group.  Also of note, despite the fact that 21% of those in the intervention group quit smoking compared to only 6% in the control group, the intervention group had more lung cancer.  The researchers attributed this to the fact that those on the low-fat diet had lower cholesterol levels, hence were more likely to succumb to cancer.  I would concur.

The other NHLBI study was the Lipid Research Clinics (LRC) Coronary Primary Prevention Trial.  This trial collected 3,800 men who had cholesterol levels over 265 mg/dl, considered imminently likely to suffer a heart attack.  All of the participants were counseled to eat a cholesterol-lowering diet, but half of them took a cholesterol-lowering drug called cholestyramine, while the control group took a placebo.  So, to clarify, the only difference between the two groups was the presence or absence of the cholesterol-lowering drug.  This means that the only variable being tested was the effectiveness of the drug, nothing else.  Here are the results:  In the control group, cholesterol levels dropped 4%, 158 men suffered non-fatal heart attacks, 38 died from heart attacks, and overall 71 men died.  In the group receiving cholestyramine, cholesterol levels dropped by 13%, 130 men suffered non-fatal heart attacks, 30 died from heart attacks, and overall 68 men died.  Putting the heart disease numbers aside, 71 deaths versus 68 deaths.  This means that the cholesterol-lowering drug had improved by less than 0.2% the chance that any one of the men who took it would live through the next decade.  Very insignificant.  Any right-minded person would wonder, then, how such an unimpressive cholesterol-lowering drug trial was featured in Time magazine as proof that cholesterol was a plague to us all, and that we need to lower our cholesterol by eating low-fat, low-cholesterol diets.  The heading of the article read "Sorry, It's True. Cholesterol Really Is a Killer."  Basil Rifkind, who headed the study, was quoted in the article as saying, "It is now indisputable that lowering cholesterol with diet and drugs can actually cut the risk of developing heart disease and having a heart attack."  That may be true, but it doesn't appear to save any lives, and that's the ultimate goal. 

I hope it is clear at this point that the research backing the diet-heart hypothesis is surprisingly thin.  You would think that for an entire nation to adopt these low-fat diets as the gold-standard in healthy eating, and most of the civilized world for that matter, there would need to be a wealth of research supporting it.   As I've shown here, the science is ambiguous at best, but by this point, the media had grabbed a hold of the low-fat diet so hard that it would never let go.  The USDA Dietary Guidelines for Americans are republished every 5 years and they're considered to be the most comprehensive, unbiased assessment of the science by many in the field of nutrition, even though they've barely changed since 1980.  Dietitians blindly take it as truth and implement it in their work often without questioning it.  To them I say, get some historical context.

Next time, in what will definitely be the last part of this Historical Context series, I'll wrap up all of this information in a nice, neat little package and attempt to bring it all together.

Thursday, March 24, 2011

Historical Context, Part 4 - Dietary Goals for the United States

Probably the most influential event in the acceptance of the diet-heart hypothesis, the one that finally cemented the idea that we should all eat less fat and cholesterol, was the 1977 publication of Senator George McGovern's Dietary Goals for the United States.  This was, in McGovern's words, "the first comprehensive statement by any branch of the Federal Government on risk factors in the American diet."  In other words, until now, government had never told Americans what they should be eating.  Unfortunately, what led to the publication of these guidelines had little to do with nutritional science.

The influence of Ancel Keys on this process cannot be understated.  The man should take a large part of the credit (or blame) for convincing the country to fear fat, not just through his research but also through his influence on the American Heart Association (AHA), for which he was a board member.  As early as 1960, a full 17 years prior to the government recommendations, the AHA had begun recommending that Americans eat less saturated fat and cholesterol by avoiding red meat.  By 1970, the AHA had broadened their recommendations to all Americans (formerly they only applied to those with high cholesterol and smokers) and had begun an alliance with the vegetable oil and margarine manufacturers.  Two of these major manufacturers began distributing a "risk handbook" to doctors all over the country, touting the benefits of avoiding saturated fats and eating more polyunsaturated fats from vegetable oils like corn oil.  Doctors, of course, would begin passing this information along to their patients; all it took now was to add a label to a product saying "low in saturated fat and cholesterol" and poof! it's a health food in the public eye.  This alliance between the AHA and the vegetable oil manufacturers dissolved in the early 1970's due to research showing that polyunsaturated fats from vegetable oils and margarine could cause cancer in rats.  Nevertheless, the AHA was becoming more and more well-known by the public and would soon be considered a trusted source.  Today, you can find the AHA logo on such heart-healthy foods as Cocoa Puffs and Lucky Charms.

Another important political problem that was gaining momentum in the early 1970's was the problem of feeding the world's growing population.  The subject of famine in the third world was a constant presence in the news, where images of starving, impoverished children from all over the world were regularly shown.  A growing number of concerned individuals began blaming this world hunger on the wasteful American livestock industry.  The idea was brought to the mainstream through the popularity of a number of books, such as Diet for a Small Planet by Francis Moore Lappe and Appetite for Change by Warren Belasco.  According to Lappe, a 26-year-old vegetarian, the American beef industry required 20 million tons of soy and vegetable protein to produce two million tons of beef.  So, he argued, we would be doing the world's growing population a favor by bypassing this process and simply subsisting on the soy and vegetable protein ourselves.  This argument transformed meat-eating into a social issue, as well as a moral one.  Wrote Warren Belasco in Appetite for Change, "A shopper's decision at the meat counter in Gary, Indiana would affect food availability in Bombay, India."  In the eyes of these people, there wasn't enough food for everyone because the food industry was feeding it to cattle to support our meat-loving nation.  Coincidentally, this sentiment ran parallel to the AHA's stance that Americans should eat less saturated fat, especially red meat.  Just to clarify, I'm not some cold bastard who doesn't care about starving children in the third world, I'm simply trying to make the point that there were other factors at play in this whole diet-heart hypothesis deal that had nothing to do with recommending an optimal diet for health.  Besides, in 1968, before this public starvation scare even took hold, Norman Borlaug created high-yield varieties of dwarf wheat that had ended famines in India and Pakistan and averted the predicted mass starvations.  The hunger problem was already on its way to a solution.

And now we come to Senator George McGovern.  The aforementioned document, the 1977 Dietary Goals for the United States, was a product of McGovern's Senate Select Committee on Nutrition and Human Needs, a bipartisan nonlegislative committee that had been formed in 1968 with a mandate to wipe out malnutrition in America.  In its first five years, McGovern and his colleagues were very successful in implementing federal food-assistance programs to feed the hungry in America.  But by 1977, McGovern's Senate Select Committee was in danger of being reorganized and downgraded to a subcommittee, which would operate under the Senate Committee on Agriculture.  As investigative reporter William Broad explained it in a 1979 article, the Dietary Goals constituted a last-ditch effort to save McGovern's committee from reorganization.  The committee members knew that this was primarily a political move.  Committee staff director Marshall Matz was quoted as admitting, "We really were totally naive, a bunch of kids, who just thought, Hell, we should say something on this subject before we go bankrupt."  So McGovern and his committee decided to "just pick one" and support the diet-heart hypothesis, and recommend that Americans consume less fat and cholesterol.  The committee used the "changing American diet" story for the basis of its position, stating that at the turn of the century Americans consumed less fat and more carbohydrates, and heart disease was rare (refer to part 2 of this series for more on that).  Incidentally, they also loved Ancel Keys' Seven Countries Study (boooo.).They emphasized the need to return to the diet of the past, reducing meat and fat intake in favor of grains and other carbohydrates.

Now, put yourself in George McGovern's shoes for a moment... by endorsing the low-fat diet, you're winning on so many levels.  First, you're promoting the Senate Select Committee's reputation, not to mention your reputation as a politician.  Let's not forget politicians' obligation to make themselves look good.  Second, you're promoting a diet that can feed more people, the kind of diet that a government can get behind.  And third, you're giving the American people concrete advice to follow that you believe will improve their health.  The Dietary Guidelines were a culmination of all of these factors.  The major problem with the guidelines, however, was that now the public thought the debate was over; that fat and cholesterol were killers... and the science didn't support that.  The guidelines make it seem as though the data was clear, while in reality it was anything but.  Skeptics would continue to say that more research was needed in order to offer accurate advice, but unfortunately "more research needed" isn't particularly quotable or catchy.  The key concept to understand here is that the Dietary Guidelines for the United States was not a scientific document; it was a political one.  In the last part of this Historical Context series, I'll address the actual dietary research that refutes this low-fat and cholesterol dogma, and also discuss the ginormous impact that the Dietary Guidelines had on public opinion.

Friday, March 18, 2011

Historical Context, Part 3 - Ancel Keys

Ancel Keys, a University of Minnesota physiologist, deserves much of the credit for convincing the public that dietary fat and cholesterol are killers.  He initially became famous through his development of the "K-ration" for feeding combat troops in World War II; the "K" stood for Keys.  He then performed a series of human starvation studies and wrote the book "The Biology of Human Starvation", which made him a well-known, reputable nutrition researcher.  Originally, Keys did not believe dietary fat and cholesterol had anything to do with the rising heart disease rates, but his opinion changed when he attended a conference in Rome in 1951, where he spoke with a physiologist from Naples, Italy who boasted about the lack of heart disease in his city.  The diet in southern Italy was low in animal products, and the people there, especially the poor, tended to have lower cholesterol than those in the United States.  The rich in Naples, however, ate more meat, and had higher cholesterol levels and heart disease rates.  This convinced Keys for the first time that dietary fat from meat was driving the heart disease epidemic in the United States.

There were two key observational studies performed by Ancel Keys that ended up having an impact on the public's view of dietary fat.  The first, which many researchers did not taken seriously, was the 1953 study he performed involving six countries, comparing their fat intake to their heart disease rates.  The six countries he reported on (United States, Canada, Australia, UK, Italy, and Japan), showed a very strong association between fat intake and heart disease.  Now, of course, this is only an observational study and no cause and effect can be determined.  But the biggest problem with his study is that he left out the data from the 16 other countries for which data was available.  When all 22 countries are considered, his perfect correlation turns into a much weaker one.

Initially, in 1957, the American Heart Association (AHA) opposed Ancel Keys on the diet-heart hypothesis.  They wrote a 15-page report that year denouncing Keys and similar researchers for jumping to conclusions about the diet-heart hypothesis when there was no good evidence that it was true.  Less than four years later, in December of 1960, the AHA flipped their stance and adopted the diet-heart hypothesis as their new philosophy on heart health, proclaiming that "the best scientific evidence of the time" strongly suggested a low-fat diet, or at least replacing saturated fats with polyunsaturated fats, is preventative of heart disease.  What had changed in that four-year period?  Not the evidence.  There was no new evidence to either confirm or reject the diet-heart hypothesis.  What had changed is that Ancel Keys and Jeremiah Stamler, another supporter of Keys, had now made up two of the six members on the AHA committee.  Soon after, Ancel Keys was enshrined as the face of dietary wisdom in America in an article in Time magazine.  The article discussed Keys' idea of a heart-healthy diet as one in which nearly 70% of calories came from carbohydrates and just 15% from fat.  Despite the fact that there was ZERO evidence from clinical trials to back up this claim, the article only contained one short paragraph explaining that Keys' hypothesis was "still questioned by some researchers with conflicting ideas of what causes coronary heart disease."

The second important study done by Ancel Keys was considered to be his masterpiece, The Seven Countries Study.  This study is still, today, considered to be a landmark study because of the pivotal role it played in the acceptance of the diet-heart hypothesis.  Launched in 1956, Keys' followed 16,000 middle-aged men for over a decade and tracked their diets and their heart-disease risk.  The populations he chose came from seven countries:  Italy, Yugoslavia, Greece, Finland, the Netherlands, Japan, and the United States.  The results showed, again, a remarkably clear association, but this time the association was between saturated fat and heart disease.  Keys drew three conclusions from this study:  1. Cholesterol levels predicted heart disease.  2. The amount of saturated fat predicted cholesterol levels and heart disease.  3. Monounsaturated fats protected against heart disease.

Seems pretty clear huh?  Not quite... there are a number of problems with the study.  First and foremost, this is an observational study, and like I've said a million times, you cannot determine any causality from it.  Secondly, Keys chose countries that he knew would fit his hypothesis.  Had he chosen at random, he may have included countries like France or Switzerland that consume high amounts of saturated fat and have very little heart disease.  Third, we know now that middle-aged men are the only population for which total cholesterol numbers can predict heart disease, and the Seven Countries Study only looked at middle-aged men.  Lastly, and perhaps most importantly, Keys didn't look at total mortality, even though what we really want to know is whether or not we'll live longer.  Coronary heart disease accounted for less than a third of deaths.  He said himself in a 1984 follow-up paper, "little attention was given to longevity or total mortality."  Interestingly, if all-cause death had been taken into account, Keys would have found that the American population he studied lived longer than any other population with the exception of the Crete islanders, despite their high cholesterol. 

Even with all of the problems with Ancel Keys' research, his findings on saturated fat and cholesterol would have a profound impact on the public due to a sort-of perfect storm of events that would eventually lead up to the first government dietary recommendations, Senator George McGovern's 1977 Dietary Guidelines for America.  More on that in part 4!

Wednesday, March 16, 2011

Historical Context, Part 2 - The Diet-Heart Hypothesis

In the 1950's in America, the diet-heart hypothesis was born, theorizing that the fat in our diets caused heart disease.  Proponents of this hypothesis had two very compelling reasons to believe in it.  First, was the increase in heart disease rates, which more than doubled since the 1920's.  The other was the "changing American diet" story; the idea that at the turn of the century, Americans were consuming significantly more grains and less meat and were healthier for it.  These two ideas together formed the basis for the diet-heart hypothesis.  The fat-laden diet of the 1950's must have been the reason for the skyrocketing heart disease rates, right?  I would say no.  Both of these ideas, the foundation for the diet-heart hypothesis, are easily explained by other phenomena.  Much of the information in this and the rest of this historical series will come from Gary Taubes' fantastic book Good Calories, Bad Calories.  I'd recommend it to everyone, but it's so information dense that it reads sort of like a textbook.  Luckily, you have me to summarize for you.

First on the list is the belief that heart disease was rare before the 1920's and grew into America's #1 killer by the 1950's.  Census data showed in 1910 that only 250 Americans out of every thousand would die from heart disease, but in 1950, that number had risen to 560, more than double.  So the real question is, then, did heart disease rates really increase, or was there simply an increase in the awareness of the disease, or perhaps better technology to diagnose it?  As it turns out, the use of the newly invented electrocardiogram in 1918 made heart disease much more easily diagnosable.  People were living longer by the 1950's too due to antibiotics that could control infectious disease; life expectancy had increased from 48 years in 1900 to 67 years in 1950.  As we know today, very few heart attacks are seen in 48-year-olds, and obviously the longer one lives the more likely one is to develop a chronic disease like heart disease or cancer, which, incidentally, also increased in this time span.  An increase in heart disease diagnoses was also due to newly discovered variations of heart disease, like the new cause-of-death category added in 1949 for arteriosclerotic heart disease.  From 1948 to 1949 alone, total heart disease rates increased by 20% for white males and 35% for white females.  A similar pattern was then seen when a category for ischemic heart disease was added in 1965.  Based on all of this information, it appears that this "great epidemic" may not have roots in diet at all.

The other half of this argument, the "changing American diet" story can be challenged as well.  Ancel Keys, a University of Minnesota researcher who will be the subject of the next piece in this series, wrote in 1953, "The present high level of fat in the American diet did not always prevail, and this fact may not be unrelated to the indication that coronary disease is increasing in this country."  Keys, and other supporters of the diet-heart hypothesis, envisioned the turn of the century as an era free of chronic disease due to a high-carbohydrate, low-fat diet. The food disappearance data, though, which this assertion is based on, were not reliable.  The statistics date back to 1909, but the USDA only began compiling the data in the early 1920's.  The resulting numbers for per-capita consumption are acknowledged to be, at best, rough estimates.  Here's an example of the kind of data I'm talking about:  this one shows estimated flour and grain consumption.

The data before 1942 were particularly sketchy, especially when it came to any foods that were grown in a garden or eaten straight off the farm, such as animals slaughtered for local consumption.  In fact, David Call, a former dean of the Cornell University College of Agriculture and Life Sciences, when asked about the early food disappearance data, stated that "Until World War II, the data are lousy, and you can prove anything you want to prove."  Historians of American dietary habits can provide some insight into the diet before the turn of the century, siting several sources indicating that in the 1800's, Americans were a nation of meat-eaters, typically eating meat 3 or 4 times per day.  Also of historical note is the fact that at the turn of the century, pasta was considered by the general public to be "a typical and peculiarly Italian food", according to The Grocer's Encyclopedia of 1911, and rice was still an exotic item imported from the Far East, so Americans may not have been eating much of these foods.  But, if it is true that grain consumption was high and meat consumption was low by 1909, it was probably a brief departure from our meat-based diets of the past.  At the time, the cattle industry was reportedly having trouble producing enough meat to feed the growing United States population, so there would have been less meat available.  Americans would have had to cut back.

What is most interesting to me, is that if these diet-heart hypothesis supporters wanted to use the food disappearance data as evidence to support their claim, why then did they choose to ignore the data on fruit and vegetable consumption?  In these years between 1909 and the 1950's when heart disease rates doubled, vegetable consumption increased dramatically.  Americans nearly doubled their consumption of leafy green and yellow vegetables, tomatoes, and citrus fruit.  Why was this not taken into account?  This is one of many examples of proponents of the diet-heart hypothesis choosing to ignore the evidence that doesn't support their ideals.  This is exactly the type of thing a good scientist tries to avoid, but this type of bias occurred frequently in the development of the low-fat theory.

So in the end, the diet-heart hypothesis was created in order to provide an explanation for the "heart disease epidemic".  But if you look deep enough, there was already an explanation for it; one that made a whole lot more sense.  And if you look at American dietary history before 1909, it looks like we ate a lot of meat, making the low-meat, high-grain diet of the early 19th century a deviation from the norm.  Taken one step further using the lens of evolutionary biology, which they did not have the luxury of in the 1950's, prehistoric humans ate more meat than Americans ever did, they lived into their 70's, and heart disease was virtually nonexistent.  Nonetheless, many researchers, Ancel Keys in particular, became enamored with the idea that a low-fat diet was the key to keeping heart disease at bay, and he was determined to prove he was right.  Stay tuned for part 3!

Tuesday, March 15, 2011

Historical Context, Part 1 - Hunter-gatherers

It's no secret that I tend to disagree with the mainstream dietary advice we're getting from the government recommendations.  I'm clearly in the minority here, but I would attribute that to the fact that the majority of people don't dig deep enough into nutrition to find the truth.  The information that makes it to the public eye has become so convoluted, through politics, lobbyists, capitalism, etc, that it's just an incoherent mess.  I may go into that conflict of interest on another day, so let's close that can of worms for now. 

What I'd like to do, in an attempt to make my view seem a little less crazy, is provide some historical context to the human diet and how we came to where we are today.  In my opinion, knowledge of history is vital to understanding any topic of interest.  In order to know where you stand, you must know where you came from.  I'll begin with a review of hunter-gatherer diets and move through up to the current era, when we began to believe in this high-carb nonsense.  So without further delay, here is part one of this historical context series.

For more than 99% of human history, our diets were drastically different than they are today.  Before the adoption of agriculture began in approximately 8000 B.C.E., humans hunted and gathered their food, consuming whatever was available to them in their environment.  And "whatever was available" definitely did not include grains, legumes, or dairy, although there is some evidence that grains were eaten in emergency situations when there were no other options.  The most commonly sited example of hunter-gatherer diets is the example from northeast Africa.  According to Loren Cordain and S. Boyd Eaton, two of the leading researchers in paleolithic nutrition, the diet of northeast Africans is likely the ideal human diet because the majority of human history likely took place here; we are in fact nearly 100% genetically identical to these African ancestors.  A typical African hunter-gatherer diet would consist of wild meat, vegetables, fruit, nuts, and seeds, clearly a stark contrast between the diets of modern civilization.  Note the large meat and fish consumption, which was much higher than ours today.  A typical hunter-gatherer would have consumed 55-65% of his calories from meat and fish. Research shows that vegetable and fruit consumption was much higher than in modern diets as well, even the most vegetable-rich modern diets. In terms of macronutrient ratios, African hunter-gatherers would consume 25-30% of calories from protein, 30-35% from carbohydrates, and 40-45% from fat. In contrast, modern Americans consume 15% of calories from protein, 55% from carbohydrates, and 30% from fat.

Once humans migrated out of Africa, approximately 100,000 years ago, they survived and thrived on a  variety of diets.  Some migrated to similarly warm climates and probably ate a similar diet, but many moved to colder climates where there were far fewer edible plants.  In these cases, they relied much more heavily on animals, especially in the winter months.   The latest ice age, which spanned from 60,000 years ago to 20,000 years ago, also had a significant impact on human diets, forcing them again to rely on mostly, and sometimes exclusively, animal foods.  In these cases, fat must have made up at least 70% of their calories, and probably even more than that.  As a general rule, those who settled in colder climates ate more calories from animal products, while those in more tropical climates ate more fruit and vegetables year round.

Clearly, humans were able to adapt and survive eating a wide variety of foods.  But none of these groups ate grains, legumes, or dairy as any significant part of their diets until the agricultural revolution, which began around 10,000 years ago.  At this time, domestication of animals made dairy foods a possibility, and the ability to grow food made grains (whole grains, mind you) an important part of the human diet.  Aside from obvious benefits of agriculture, though, like the ability to feed a larger population, human health took a hit.  In fact, there are a surprising number of unfortunate consequences that resulted from the adoption of agriculture, but this post is already too long and I'd rather not explain them.  If you're interested, check out Jared Diamond's outstanding article entitled "The Worst Mistake in the History of the Human Race."  But the idea that human health declined after the agricultural revolution is not debatable, despite the fact that it is contrary to popular belief today.  Humans essentially sacrificed health in order to support a greater population.

In part 2 of this series of blog posts, I'll fast forward to 20th century America and we'll begin to get into modern nutritional science.  Stay tuned.

Saturday, March 12, 2011

A Tale of Two LDL's

When looking at blood lipid profiles, doctors tend to stress LDL cholesterol to their patients, but high LDL levels alone don't necessarily indicate high risk of heart disease.  It turns out, further research has uncovered that there are in fact two types of LDL.  You have pattern A LDL, which is large and fluffy, and you also have pattern B, which is small and dense.  The large, fluffy type is not associated with an increased risk of heart attacks, while the small, dense type very much is.  People with these larger LDL particles tend to have normal levels of other risk factors:  they typically have high HDL and low triglycerides.  People with small LDL experience the opposite:  they typically have low HDL and elevated triglycerides.  These two types of LDL clearly exhibit the exact opposite effect in terms of cardiovascular health, so why are we still so concerned with LDL?  Well, probably because doctors don't normally test for LDL particle size.  Maybe they should hop on that.

The discovery that there are two very different types of LDL has far-reaching implications, most notably in the saturated fat debate.  For years, the USDA Dietary Guidelines have stressed to us that we should reduce saturated fat and cholesterol intake because they raise LDL levels.  So what if they raise LDL levels?  Do they raise pattern A or pattern B LDL?  Research shows, saturated fat in the diet tends to raise the benign, large, fluffy pattern A LDL.  This study from Sweden shows that people who consume more milk fat (whole milk, cheese, butter, etc.) have predominantly large, fluffy LDL.  This study from UConn and this one out of Mexico both show that consumption of eggs, which are high in both saturated fat and cholesterol, result in the non-atherogenic large, fluffy LDL.  This of course makes evolutionary sense as well.  It is estimated that hunter-gatherers consumed at least 10-15% of their calories from saturated fat.  The Dietary Guidelines say we should keep it under 10%.  Maybe the USDA should actually read research instead of making recommendations that will sell more processed foods made from corn and soy.

My advice:  pay no attention to your overall LDL level and don't fear saturated fat or cholesterol.  Your total LDL number is meaningless unless you know which type of LDL you predominantly have.  Even if your doctor doesn't check for LDL particle size, though, there is still a good way to predict which type of LDL you've got.  If your HDL is high and your triglycerides low, you're probably safe regardless of your LDL count because it's going to be the large and fluffy pattern A.  If your HDL is low and your triglycerides high, then you're in trouble, even if your LDL level isn't high.  In the end, it looks like total LDL just isn't all that important of a predictor of heart disease.  If you've read this and my previous blog post, you have to wonder...  why is everyone so concerned about cholesterol??

Wednesday, March 9, 2011

High Cholesterol = Longer Life?

The issue of cholesterol is complex, to say the least.  You might not realize it from watching cholesterol-lowering drug commercials, or even from talking to your doctor.  But there is way more to the story than simply keeping your cholesterol low.  This will probably be a frequent topic on my blog, as there are so many aspects of it to be explored, but for today I'd like to focus on total cholesterol.

Check out this very eye-opening paper.  It's an outstanding review of some of the more intriguing cholesterol research, and one of the few papers that I've actually found difficult to put down.  I seriously couldn't stop reading it.  And it blew my mind.

According to several studies, older adults with higher cholesterol live the longest. In fact, groups with the lowest cholesterol levels typically have the highest morbidity rate.  Here's the breakdown from a couple of these studies...  Dr. Harlan Krumholz found in 1994 that old people with low cholesterol were twice as likely to die from coronary heart disease than those with high cholesterol.  Another study of 92 women aged 60 or over found that those with a total cholesterol level of about 270 mg/dl lived the longest.  Those with the highest cholesterol, over 300 mg/dl, were only 1.8 times more likely to die, while the lowest cholesterol group, 154 mg/dl, was 5.4 times more likely to die.

Interesting stuff huh?  That review paper discusses 20 studies just like these, where blood cholesterol levels were either not associated with cardiovascular disease or all-cause death, or there was an inverse relationship.  This quote from the paper sums up the situation quite nicely...

"It is true that high t-C is a risk factor for coronary heart disease, but mainly in young and middle-aged men. If high t-C or LDL-C were the most important cause of cardiovascular disease, it should be a risk factor in both sexes, in all populations, and in all age groups. But in many populations, including women, Canadian and Russian men, Maoris, patients with diabetes, and patients with the nephrotic syndrome; the association between t-C and mortality is absent or inverse; or increasing t-C is associated with low coronary and total mortality. Most strikingly, in most cohort studies of old people, high LDL-C or t-C does not predict coronary heart disease or all-cause mortality; in several of these studies the association between t-C and mortality was inverse, or high t-C was associated with longevity. These associations have mostly been considered as a minor aberration from the LDL-receptor hypothesis, although by far the highest mortality and the greatest part of all cardiovascular disease are seen in old people."

 In case you're having trouble with the terminology, t-C just means total cholesterol, LDL-C means LDL cholesterol.  A couple of key points here...  if cholesterol is the cause of heart disease, then shouldn't it be a risk factor for everybody, regardless of age, sex, or ethnicity?  It should.  But it's not.  While cholesterol levels can be somewhat predictive of one's risk of heart disease, cholesterol doesn't cause the problem.  The second bolded quote is very key as well.  Studies done in older adults, like these ones showing that those with high cholesterol have less risk of cardiovascular disease, should not be taken as an aberration.  By far the highest risk group is adults over 60, so if the conventional wisdom doesn't hold true for them, it doesn't hold true at all.  These studies should indicate that our current thinking about cholesterol is highly flawed.  Cholesterol simply cannot be the cause of heart disease when it is so notoriously unreliable as a predictor of heart disease in the most at-risk populations.  It's that simple.

Sunday, March 6, 2011

Dietary Fat and Breast Cancer, Part 2

Finally, on to part 2.  Let's talk about a study I found through showing that a high fat and cholesterol diet causes faster growth and proliferation of tumors than a "normal" diet.  The study was done in rats; the control group of rats received rat chow 5010, while the other group received a higher fat "Western Diet 57BD."  Looking at the macronutrient breakdown, there appears to be nothing wrong with the diets.  The rat chow diet consisted of 29% protein, 13% fat, and 58% carbohydrates, while the Western diet contained 15% protein, 41% fat, and 44% carbohydrates.  You can read the whole study and find nothing about the actual ingredients in the diets, but a quick Google search will yield you the spec sheets.  Here are the contents of the control group's rat chow:
  • Ground corn
  • Dehulled soybean meal
  • Wheat middlings
  • Fish meal
  • Ground wheat
  • Wheat germ
  • Brewers dried yeast
  • Ground oats
  • Dehydrated alfalfa meal
  • Porcine animal fat
  • Ground soybean hulls
  • Soybean oil
  • Dried beet pulp
  • Added vitamins and minerals
And for the Western diet...
  • Sucrose (31% by weight)
  • Milk fat (21%)
  • Casein (19 %)
  • Maltodextrin (10%)
  • Powdered Cellulose (5%)
  • Dextrin (5%)
  • Added vitamins and minerals
Problem #1 - The Western diet group didn't even receive real food... these are chemically isolated compounds that have been removed from their real-world context.
Problem #2 - Their diet consisted of 31% sugar????  That's their main carbohydrate source.  Sugar.  There's a lot of research showing a link between insulin and cancer growth, and sugar requires a hefty insulin release. Here, here, and here.  And this study, which studied mammary tumor growth, showed that mice fed sucrose had 100% tumor incidence, meaning every single mouse developed breast cancer.
Problem #3 - Casein.  Casein, which is a protein derived from milk, was used in rat studies conducted by T. Colin Campbell, who wrote The China Study.  He found that a diet of just 5% casein promotes tumor growth in rats.  The diet in this experiment has 19% casein.

So how can the researchers claim that a high-fat and cholesterol diet proliferates cancer cell growth?  If they really wanted to test their hypothesis, they would have done their best to keep as many variables as possible unchanged between the two groups.  They wouldn't have fed the experimental group a laundry list of chemically isolated compounds.  So in my mind we have two possible reasons why the researchers would have used a diet full of known cancer-promoting non-food items.  One, they're stupid.  And I refuse to believe they're stupid, because they wouldn't be where they are today without knowing the basics of science.  The second option, which I like, is that the researchers' goal from the beginning was to confirm their hypothesis.  So they fed the rats a diet which, while higher in fat, was also higher in substances which would be sure to cause tumor growth.  I don't know why they would have done this, perhaps there was some influence from the drug or food industries.  Maybe the researchers had giant egos and were so convinced high-fat diets promoted cancer that they didn't want to risk being wrong.  The only thing I know for sure is that this is really bad science.

Saturday, March 5, 2011

Side Note on Sunlight and Vitamin D

Perhaps I should have elaborated more on the vitamin D and cancer connection.  I doubt anyone will actually watch that one-hour vitamin D lecture I posted a link to, and I know everyone's been told for years to stay out of the sun because it'll give you skin cancer.  So simply telling you that sun exposure reduces cancer rates probably isn't convincing.  Allow me to explain myself.

First off, how serious is the skin cancer problem?.  One look at the cancer statistics from 2010 shows that non-melanoma skin cancer is surprisingly benign.  In 2010, less than 1,000 people in the United States died from skin cancer.  That's about 0.0003% of the population, and less than 0.2% of total cancer deaths, according to the National Cancer Institute's statistics.  There are at least 12 other types of cancer that are more deadly.  Perhaps the problem has been a bit overstated.

But on to the task at hand.  Let me begin with these two maps... the one on the left shows the amount of UVB radiation received across the nation, and on the right is a map of breast cancer prevalence.  There are maps like this for all types of cancer, and they all show similar patterns.

They're strikingly similar.  Areas with more UVB exposure, the type of sunlight that your skin uses to make vitamin D, tend to have lower cancer rates.  Here's another chart, this one's pretty old, but still very relevant...

Cities that see more solar radiation from the sun have lower rates of breast cancer.  But like I explained in my last post, correlations like these don't indicate causality.  That's where the new research on vitamin D comes into play.  High blood levels of vitamin D, 25(OH)D, are clearly associated with a lower risk of cancer.  According to this study, supplemental vitamin D combined with sun exposure is enough to raise blood levels of vitamin D to 52 ng/ml, a level that is associated with a 50% reduction in the incidence of breast cancer.  Another study, this time a controlled, clinical trial, tested the impact of vitamin D and calcium supplementation on cancer rates in postmenopausal women.  The study showed that the group receiving both vitamin D and calcium, as opposed to just calcium, or a placebo, showed a "60% or greater reduction in all forms of cancer."  Very significant.

Let's put this all together.  Climates receiving more UVB exposure from the sun, the type that forms vitamin D in our bodies, are associated with lower cancer rates.  High vitamin D blood levels are associated with lower cancer rates.  Vitamin D supplementation significantly lowers the risk of developing cancer.  Add to this the fact that it makes evolutionary sense that the sun would be beneficial for us:  When humans migrated further and further from the equator, their skin became lighter and lighter, becoming more efficient at making vitamin D through limited sun exposure.  And while we're at it, throw in some common sense too:  Why would the very thing that gives us life on earth, the sun, kill us at the same time?  Connect the dots, and it looks like sun exposure probably prevents cancer more than promotes it.  At least that's my interpretation of the evidence.

Now I'm not saying you should go out in the sun and tan all day long to the point where you burn.  That's not good for anybody.  However, it is completely unnatural to avoid the sun altogether.  There's nothing wrong with moderate sun exposure.  And take it easy on the sunscreen.  Sunscreen prevents UVB absorption, meaning you won't get burned but you also won't make vitamin D.  If you'll be in the sun all day, at least hold off on the sunscreen until you've had a chance to get the benefits of sun exposure. 

Could it be that the conventional medical advice to stay out of the sun has actually caused more cancer than it has prevented??  Let that marinate for a while.

Thursday, March 3, 2011

Dietary Fat and Breast Cancer, Part 1

Ah, dietary fat.  So delicious, yet so frowned upon.  If you look hard enough, you can find dietary fat associated with just about anything out there, from heart disease, to diabetes, to colon cancer, even in-grown toenails (not really).  But the breast cancer link is something I've heard about for years in the media, and from talking to people who watch too much local news.  A few weeks ago, in one of my classes, my professor showed us a graph of the relationship between dietary fat intake and prevalence of breast cancer by country. Here it is... you'll probably have to click on it to view the full-size version.

I found this one through a Google search.  Interestingly, the two points that don't seem to fit in line with the others, South Africa and Israel, were left out of the graph we saw in class, I guess my professor gave them the Ancel Keys treatment... but that's not the point here.  At first glance, this looks like a pretty strong relationship.  The more fat a nation eats, the higher its rate of death from breast cancer.  And even though this is just a correlation, meaning no cause and effect can be determined, it certainly piqued my interest.  I'm always very skeptical any time a study blames fat for anything; I find it impossible not to be after reading Good Calories, Bad Calories.  And I began to wonder, what else could possibly account for this correlation?  And that's when it clicked.  Sunlight.

If you look closely at the graph, the countries that consume less fat and have less mortality from breast cancer tend to be warmer climates, while the ones that consume more fat and have more mortality from breast cancer are colder climates.  Knowing that vitamin D (from sunshine) seems to have strong anti-cancer properties, of course the countries that get more sun would have less mortality from breast cancer.  If you're interested, watch Dr. Mercola's lecture on vitamin D, I don't want to get into the details here.  So I decided to plot this information in an excel graph.  I estimated the degrees of latitude from the equator for each country, and plotted that against breast cancer mortality rates.  Here's what I came out with...

That's what is called a confounding factor.  Not quite as neat of a correlation as the dietary fat graph, but there's clearly an association there.  So what does all this mean?  Does it mean vitamin D is the problem, not dietary fat?  I'd put my money on vitamin D deficiency playing a larger role in the deaths from breast cancer than dietary fat intake.  Actually, I'd argue against the very notion of lumping all types of fat into one group like this, doesn't make sense... but that's a topic for another day.  From an objective standpoint, you can't infer much of anything this data.  In observational studies like these, there are so many uncontrolled factors involved that you can't determine any cause and effect at all.  Here's a few other confounding factors that could be at play here...
  1. People who eat less fat tend to eat more vegetables.
  2. People in warmer climates are able to grow vegetables for a longer part of the year, so are more likely to eat them.
  3. People in cooler climates tend to eat more refined grains.
  4. People in warmer climates are more likely to get more physical activity.
I bet if I could plot that information in three more graphs, I'd get nice correlations as well.  The point is that when you see something on the local news about how breast cancer is associated with dietary fat, it doesn't mean dietary fat causes or even influences breast cancer.  It just means that the two occur at the same time.  Did you hear that fire trucks are associated with fires?  It's true, there's a strong association between fire trucks and fires, every time there's a fire, fire trucks are there... they must be causing the fires!  No...

What these observational studies are actually good for, however, is to form hypotheses that can be tested in more controlled trials.  It's been done in rats, and quite poorly I might add... we'll discuss that in part 2 of this series.

Wednesday, March 2, 2011

Robb Wolf and Art Devany on ABC Nightline!

Paleo has gone mainstream! Sort of.  I think it's great that these guys were able to do a story on a huge mainstream media outlet like Nightline, that is fantastic for getting the word out.  They're going a bit overboard with the "caveman" stuff, making it seem like sort of a novelty or a fad, which it is NOT!  But any publicity is good publicity I suppose.  At least it's better than the kind that Charlie Sheen is getting these days.  Check out the Nightline story here

Tuesday, March 1, 2011

The $#!T We Used To Know

People think I'm crazy.  When I say things like "grains aren't healthy" or "saturated fat might even be good for you", people probably tend to ignore me; everyone knows grains should be the foundation of a healthy diet, and saturated fat causes heart disease.  Today, I'd like to bring up a few historic examples of the ridiculous "facts" we used to know.  Brace yourself.

1.  Doctors don't need to wash their hands.  Before the 1920's, it was not common practice for doctors to wash their hands with soap before working with a patient, or even between surgeries.  Doctors didn't realize its importance until a Hungarian physician, Ignaz Semmelweis, discovered it was an effective means of preventing common diseases.  Could you imagine a doctor performing a surgical procedure on you, right after he had his hands all up inside another patient?  It used to happen.

2.  Frontal Lobotomy for mental illness.  In the mid 1900's, a procedure called the lobotomy was used in an attempt to cure mental illness.  In fact, Antonio Egas Moniz received the Nobel Prize for Physiology or Medicine in 1949 for his discovery of the therapeutic value of the procedure in treating certain conditions.  So what exactly is a frontal lobotomy?  Doctors would impale a patient's head with a large needle, forming a rather large hole from the inside of the left eye socket all the way to the prefrontal cortex of the brain.  Yes, they literally stabbed patients in the head.  The procedure may have been somewhat effective in reducing symptoms of mental illness, but it predictably had side effects.  As many as 3% of patients were killed by the procedure, according to the 1970 Psychiatric Dictionary.  But besides that, it essentially made the patients easier to control by reducing their mental capacity.  Good for nurses in the psychiatric ward, bad for humanity in general.

3.  Exercise ruins your bones.  This myth was commonplace until the 1950's.   The typical conventional wisdom of the day was that resistance training wears down your muscles and bones, and should be avoided, especially by older adults who are at risk of degeneration and osteoporosis.  Today, this sounds ridiculous.  Personally, I don't know how anyone ever believed this.  If you look at it from a historical perspective, always useful, people knew lifting heavy things was good for you as far back as Ancient Greece.  Not sure how the message got lost in translation but, at least that myth is dead now.

4.  The sun revolves around the earth.  Yup.  Before the early 1600's, everyone knew Earth was the center of the universe.  That is, until Galileo Galilei came along with his telescope and determined mathematically that the earth was in fact orbiting the sun, not vise versa.  The Roman Inquisition, of course, didn't like that because it challenged the Catholic Church's view that God created the earth and made humans to run the place because they are above the laws of nature because they can control it by growing their own food and invent new ones like bread, and by coercing formerly wild animals to live beside them only to be killed for their consumption.  That may have been a run-on-sentence.  But the point is we know now that the sun is the center of our solar system and Galileo was right all along.  Take that Pope.

5.  Cigarettes are endorsed by physicians.  This one might not be too hard to believe, I mean considering all the drugs physicians support these days.  But it's true, doctors used to support cigarettes for "throat protection against irritation against cough."  Grammatical considerations aside, it actually took a long time for the tobacco companies to finally fall to the mound of data linking smoking to lung cancer.  Today, it's widely accepted that cigarettes smoking does cause lung cancer, and we can all laugh about these old ads. 

I'm sure there are plenty more examples of this type of thing, but my point with this post is to say that people today tend to think we know everything.  These examples seem silly, knowing what we know today, but if you were able to take yourself back in time, you would probably accept the conventional wisdom just as everyone else did.  So, next time you hear something that challenges your most precious beliefs about health and nutrition, or anything else for that matter, don't simply dismiss it because "everyone knows the truth."  The conventional wisdom of the time is often far from the truth.