Whole Grain Destruction

Bread... destroyed

Aaand back to the sciencey posts.  I do like the more philosophical rant posts, but truthfully, I get my jollies off in two ways... reading about scientific research and drinking endless coffee (take note ladies).  Consider both covered.  Big nerd?  Probably.  Bored because the weather is shitty and everyone I know is at work?  Absolutely.

Today’s topic is grains.  More specifically, whole grains.  Many of you may know my stance on grains; I think they’re nutritionally useless, potentially harmful, and they often displace the more nutritious foods we could be eating (ie. fruits, vegetables, meats, seafood).   But today, I offer more convincing evidence against grains in the form of randomized, controlled scientific research.  Yup, the gold standard.

Let’s go over the levels of scientific evidence, just briefly so no one's confused.  For my purposes today, I’ll be talking about two types of study designs: epidemiological research and randomized, controlled trials.  The weaker of the two is epidemiological research.  In this type of study, participants are recruited, asked about their dietary patterns, and followed for a period of time to see who lives and who gets sick and/or dies.  It's observational in nature, and you can't infer cause and effect.  Blah, blah, blah, etc, etc, etc... the best you can do is to find a connection between two variables.  For instance, you might see that people who eat more whole grains tend to have less incidence of cardiovascular disease (1,2).  That doesn’t mean eating whole grains caused a reduction in heart disease; it just means the two happened at the same time.  It could be, instead, that people who consume more whole grains are typically more health conscious.  So in addition to eating whole grains, they exercise more, eat more fruits and vegetables, and choose not to smoke.  Maybe the grains were just along for the ride, while the other variables were what really mattered.  There's no way to know for sure.  

What you can do, though, is use this information to set up a randomized, controlled trial. In this type of study, you can isolate one variable that you think is important, like whole grains, so that you can determine cause and effect.  You need a control group, which would eat refined grains (or no grains), and an experimental group, which would eat whole grains.  Then, you can measure the difference in health outcomes; maybe vitamin/mineral status, blood sugar control, or risk of heart disease.  The key, in this case, is that you have a much clearer idea of causality. 

The point is, randomized, controlled trials trump epidemiological research.  Which is why I'm so glad I found this article by Anthony Colpo, in which he discusses all of this randomized, controlled research on grains.  There's a reason why the only research you hear to support whole grains is observational... because the controlled trials destroy them.  In fact, whole grains may be even worse than the refined variety.  Feast your eyes on this here research...

Whole Grains and Mineral Status

I've written about it before.  Whole grains are full of antinutrients, like phytates, that make minerals unavailable to the body.  This is the result...

As far back as 1949, researchers from the University of Ceylon in Sri Lanka found feeding brown rice to healthy male medical students for three weeks worsened their calcium and magnesium status, even though their intake of these nutrients was higher than when they ate white rice (3).  A 1960 paper by Indian researchers reported similar findings for calcium and warned “the exclusive consumption of brown rice in diets containing marginal or submarginal amounts of calcium is not to be recommended as it may produce negative calcium balances (4).”

In addition, a 1976 paper reported a tightly controlled metabolic ward study in Iran in which two men ate 2 different diets for 20 days each. During the first 20 days, more than 50% of their energy intake was provided by white bread. During the second 20-day period, the white bread was replaced with Bazari, a traditional whole grain bread. Apart from the different breads, the experimental diets contained identical amounts of cheese, milk, mutton, fruits and vegetables, beans, rice, turnips, oils, tea/water, and sugar.  The whole wheat bread diet was shown to significantly worsen zinc, calcium, and magnesium status, despite the increase in both calcium and magnesium consumption during this period (5).

Looks like whole grains increase your requirement for critical minerals like calcium, magnesium, and zinc.  Osteoporosis anyone?  You may even be better off with white rice and white bread!  Continuing on...

LDL Oxidation

LDL oxidation is a key player in cardiovascular disease.  LDL particles on their own may not be harmful, but oxidized LDL particles certainly are.  They may even have a causal role in the development of atherosclerotic plaque.  Having said that, check out this paper by Jenkins et al. Researchers gave type 2 diabetics a low-wheat fiber diet and a high-wheat fiber diet containing bran-rich bread and breakfast cereal for three months each. LDL oxidation increased during the high-wheat fiber phase (6).

It's only three months, which is too short to see any effect on the rate of heart disease, but increasing oxidized LDL certainly indicates a problem.

Whole Grains for Diabetics

Your run-of-the-mill dietitian will tell you diabetics need to eat brown rice instead of white rice, since it has more fiber and a lower glycemic index.  Well they'd be wrong.  Actually, brown and white rice have virtually the same glycemic index; what really matters is the type of rice.  Long grain rice strains have higher amylose contents than their short grain cousins, so wherever possible opt for long grain rices like Basmati and Doongara, as they tend to have lower GI scores than instant, converted and short-grain varieties.  Jasmine is an exception to the rule as it sports a higher GI despite its long grain status (7,8).

A recent clinical trial from China further puts lie to the claim that brown rice has some sort of anti-diabetic effect. Researchers randomly assigned 202 middle-aged adults with diabetes or a high risk for diabetes to consume either white or brown rice ad libitum for 16 weeks. No differences were noted in BMI, waist circumference, glycated hemoglobin, blood glucose or insulin concentrations between the two groups (9).  

Brown rice better than white rice?? Pshhhh, I don't think so.

Arsenic in Brown Rice

Unless you exclusively eat rice grown and watered under strict organic growing conditions, it is true that you may get a little something extra from brown rice. Unfortunately, that something extra happens to be a group 1 carcinogen. You see, vitamins, minerals, amino acids and trace elements are not the only things plants absorb from the soil and water in which they grow. Toxic metals like arsenic also find their way into plants; analyses of hundreds of varieties of white and brown rice have found the latter to contain higher levels of arsenic than white rice (10,11). The higher concentration of arsenic in brown rice is attributed to the fact it still retains its outer layers; rice bran is an especially rich source of arsenic (12).

Total Antioxidant Capacity

You've probably heard of antioxidants.  They fight free radicals, protecting our cells from damage.  Total antioxidant capacity is simply a measure of our body's ability to do this.  Do whole grains help our bodies in this regard?  Conventional nutrition may assume they do, since whole grains contain antioxidants.  Let's see... In a University of Minnesota experiment, healthy young males and females followed a refined grain diet, or a diet in which refined grains were replaced by whole grain and whole meal products in random order. Despite its higher content of the antioxidant nutrients vitamin B6, folate, selenium, zinc, magnesium and cysteine, the whole grain diet produced no improvement whatsoever in blood antioxidant capacity, nor in urinary markers of antioxidant status (13).  Looks like the answer is a clear no.

But fruits and vegetables, on the other hand, do increase our total antioxidant capacity.  When young and older adult subjects doubled their usual intake of fruit and vegetables from five to 10 servings daily, substantial increases in blood antioxidant capacity were seen after 15 days (14). In a Danish study, healthy males and females who consumed an extra 600 grams of fruit and vegetables daily for 25 days experienced reductions in lipoprotein oxidation and increases in the activity of glutathione peroxidase, an enzyme in the body that is a powerful scavenger of free radicals (15).

The lesson?  Whole grains provide shitty protection from free radicals, but fruits and vegetables are awesome.  As you know.

Heart Disease

Remember those observational studies I cited earlier?  The ones showing that people who ate more whole grains had lower rates of heart disease?  Yeah, the ones that mean absolutely nothing.  Well, the only randomized, clinical trial in existence to test the hypothesis shows no connection.  Actually, it shows a slight increase in coronary and overall mortality in those eating whole wheat (16).  I wish there were more studies done here, but the fact is it's difficult to study diet's impact on chronic disease.  It's expensive.  Maybe some day.  But for now, whole grains do NOT appear to be protective of heart disease.

Colon Cancer

We're constantly told about the benefits of whole grains for our digestive health, especially colon cancer.  While confounder-prone epidemiological studies backing this notion are easy to find, none of the numerous randomized controlled intervention trials conducted in this area support the possibility that high cereal fiber intakes prevent the progression of colon cancer (17). In fact, some of these trials noted worse outcomes in the treatment groups (18, 19).

The evidence is clear on colon cancer.  There is no benefit.  None at all.


The Bottom Line
So whole grains aren't what their cracked up to be.  And that's putting it nicely.  And this isn't just me spouting off about grains being low in nutrients (20), or me ranting about the decline in human health when we adopted grains as a food source (21).  Not that that stuff is useless.  It has its place.  But this is real science.   This is whole grains, being studied to the best of our ability, and failing miserably.

This is important.  Because everyone and their mother is currently going out of their way to eat more whole grains, putting up with the shitty taste because they think they're doing their body a favor.  You're not.  Stop it.  We need to be eating less whole grains, and less grains in general.  And I think you can now see why.  Tell all your friends.