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...

Oh, and I should probably define red meat.  Red meat signifies meat from just about every animal that isn't a bird or a fish.  That includes beef, pork, lamb, veal, bison, venison, etc.

Overcooking Meat and Cancer
      Here's something that's rarely talked.  Believe it or not, there is a wealth of information out there showing a link between overcooked red meat and several types of cancers, including that of the colon, stomach, pancreas, and prostate (1, 2, 3, 4).  Let me define "overcooked".  Meat that is medium-well or well-done is typically defined as overcooked.  Here's an example:  a National Cancer Institute study assessed the diets and cooking habits of 176 people diagnosed with stomach cancer and 503 people without cancer. The researchers found that those who ate their beef medium-well or well-done had more than three times the risk of stomach cancer than those who ate their beef rare or medium-rare.  Sorry, bloody is better (and tastier).  But there are also health risks of high-heat cooking methods, such as grilling or broiling.  It is believed that high heat cooking causes the formation of heterocyclic amines (HCAs), which are carcinogenic compounds formed from excessive browning or blackening of the meat.  Cooking with low heat by braising, boiling, or using the crockpot would be the best from this standpoint.  Not always the tastiest way to prepare meat, I know.  I'm not saying you should avoid grilling or broiling entirely, but when you do use these cooking methods, it's a good idea to cook your meat rare or medium-rare to minimize HCA formation.

So, do you think this overcooking factor is controlled for in the studies demonizing red meat?  No, not typically.  But it damn sure has a strong influence on that red meat and cancer association.

Processed vs. Unprocessed Red Meat
I've told you how I define red meat.  Beef, pork, lamb, veal, bison, and venison.  But there's something you should know about red meat studies... they often include processed meats in that definition.  That means foods like salami, slim jims, bacon, and ham, all of which can be jacked full of preservatives and chemicals, are lumped into the same category as unprocessed meats like steak and pork loin.  Anybody see a problem??  Well you aren't the only one.  Dr. Renata Micha and colleagues at the Harvard School of Public Health decided to do something about it.  In 2010, they performed a very comprehensive meta-analysis examining all of the existing research done concerning red meat and its effect on heart disease, stroke, and diabetes (5).  But they took it one step further.  They were able to separate processed red meat intake from unprocessed red meat intake.  The results showed virtually no association between unprocessed red meat and heart disease, diabetes, or stroke.  Conversely, processed meat intake was found to be associated with a 42% higher risk of heart disease and a 19% higher risk of diabetes (impact on stroke was not statistically significant).  And this was done using the very same evidence that once demonized all red meat!  It's clear that the issue is not with red meat itself; it's the act of turning it into ham and salami that is problematic.

Lifestyle Confounders
One of the problems with these observational studies is the lack of control over the participants' lifestyle choices.  What if people who eat more red meat tend to be smokers, be move overweight, exercise less, and have lower fruit, vegetable, and fiber intake?  Then I guess you couldn't blame their health problems on red meat could you?  It turns out, that's exactly what happens in these red-meat-hating studies.  Take this one, entitled "Meat Intake and Mortality", which found an association between red/processed meat and total mortality, cancer mortality, and cardiovascular mortality (6).  To quote the authors, "Subjects who consumed more red meat tended to be married, more likely of non-Hispanic white ethnicity, more likely a current smoker, have a higher body mass index, and have a higher daily intake of energy, total fat and saturated fat, and they tended to have lower education and physical activity levels and lower fruit, vegetable, fiber, and vitamin supplement intakes."  Sounds like a recipe for disaster to me.  Saying people like this were killed by red meat is like saying Amy Winehouse was killed by her coffee addiction.  It's wrong.  Smoking, overeating, lack of exercise, and lack of fruit and vegetable intake are all highly correlated with mortality.  Red meat isn't the bad guy here. 

 

       
Evolution
As I'm sure you all know, I like to use evolution and historical evidence as a lens to view anything in nutrition.  And if there was ever a time to use it, this would be it.  Red meat has been an important part of the human diet for upwards of 2 million years.  At times, hunter-gatherer societies likely lived exclusively on red meat from big game for months at a time.  In other words, we have evolved as a species for the past 2 million years using red meat as a staple food.  Cavemen didn't paint pictures of big game animals on the cave walls just out of pure boredom.  They worshiped these animals; there was no life without them.  Q:  If red meat causes heart disease, cancer, and diabetes, how is it that our ancestors were able to eat so much of the stuff and live chronic-disease-free into their 60s and 70s (only if they were able to avoid tragedy, of course), without modern medicine and conveniences?  A:  Because red meat doesn't cause heart disease, cancer, and diabetes!  Now of course, you could make the argument that the meat we eat today is different from the meat our ancestors ate.  And it was different; it came from wild, free-living animals, and the species were different than our main sources of red meat today.  But there is good news.  Pastured, grass-fed beef, which is available here, is virtually identical to the wild ruminant meat that our ancestors ate (7). Or, you could track down some wild venison (deer).  Everybody has an uncle that hunts.  But even if you can't do those things, conventional, grain-fed red meat isn't that far off from the wild meat of the past, as long as you stick to leaner cuts.  Old foods don't cause new diseases folks, it just doesn't make sense. And red meat has been around from the beginning.
        
Conclusion
So please, next time you see something in the news claiming that red meat increases your risk of dying from heart disease, diabetes, shark attacks, and drive-by-shootings, don't take it too seriously.  It doesn't mean red meat is inherently bad.  But keep the following tips in mind...
1.  Learn to like your meat rare, or at least medium rare.  And don't burn it on the outside.
2.  Avoid processed meats, especially the excessively processed ones like slim jims or shelf-stable bacon.  Any meat that doesn't require refrigeration has no business being in your body.
3.  Don't be a typical red meat eater.  Don't smoke, get some exercise, and eat your fruits and veggies.  And if you're feeling really ambitious, don't be of non-Hispanic white ethnicity (haha.).
4.  Either choose leaner cuts of meat, or eat the wild or grass-fed stuff.  There's nothing wrong with the fat, as long as you're eating the right type of meat.


Now please, go treat yourself to a steak!



3 comments:

  1. very informative, now I can enjohy a steak, stopped for awhile, don't eat a lot but would like to enjoy what I do eat.

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  2. gonna go eat a steak in your honor! thanks for this informative post

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  3. This comment has been removed by a blog administrator.

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