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...