Nutrition Science and Why It Sucks
Have you ever read one of those studies that says people who drink 2 cups of coffee a day rarely get cancer and then two weeks later and artical in the same publication that says that people who drink 2 cups of coffee a day all die ten years younger than the average life expectancy? What should we make of this? Not much. The problem with most of this data is that its either seriously flawed or seriously biased. When we do nutrition science, it’s almost impossible to hold all things constant and change just one thing - and to do that exact same thing for any large group of people. We also all have our own unique physiology and certain things will affect one person that don’t affect another person.
Let ask ourselves this question. “Does eating 20 blueberries a day decrease your risk of heart disease?” We go out and we recruit the first 200 people that walk into walmart (and I’ll help us out by saying everyone agrees to participate, but we all know that would never happen). Half of these people will be given 20 blueberries a day and the other half will not get any blueberries. I don’t know how one could possibly blind a nutrition study on th participant side. Anyway, in our study, we are just trying to study the blueberry effect, so we tell people they can eat their normal diet. Well, what is the chance that all 200 people eat exactly the same? I’m going to go with 0. We compare groups on things like age, gender, weight/bmi and probably a few other categories. But what other categories? It’s impossible to compare everything that might possibly matter - brand of toothpaste? alcohol consumption? genetic markers? maternal health history? My point is, there is just no way to get a homogenous enough group to know if blueberries really make any difference.
Let’s look at another way to do a study. I give you a food journal and you write down everything you ate in the last month. Do we need to delve into why this is never going to provide good answers? I can barely remember what I ate this morning. You want me to estimate how many servings of veggies I have a week? I can say I don’t generally eat blueberries out of season, so I haven’t had any recently, but we did get some strawberries over new years.
Finally, there is the intuitive science method. We study the food and know what it’s chemical makeup is and what vitamins it contains and therefore we know the perfect diet. Uh, does anyone thing the body is that simple? This ignores how our body interacts with the food completely.
I guess if we can’t do it that way, maybe we can find a whole population of healthy people and study their society. This is where we got the food pyramid from if anyone was wondering - and I mean the 1970s/1980s version. It started with a guy named Ansel Keyes and his groundbreaking 7 Countries Study. He didn’t mention to people that before the “7 Country Study” he did a 50 country study and picked only the ones that supported his theory. Dr. Keyes studied populations in the US, Finland, the Netherlands, Italy, Greece, Yugoslavia (that’s the land between Greece and Turkey for you youngsters who haven’t seen the Owen Wilson movie Behind Enemy Lines) and Japan. Other than being more or less heavily involved in World War 2, what do these countries share? Not much actually, but they did have carbs and not alot of fats, though, have you ever been to Italy? We took my then 8 year old and he thought it was amazing that they started every meal with a plate of charcuterie - and then we would have bread and olive oil. But in the post war devastation, I’m not sure Keyes was really studying Italian food as we would see it today in the 1950s.
So, is there any hope for having good information about nutrition? I there is on the macro level. I think it’s also likely that you will get your best nutritional information by studying your own N=1 population of yourself. It may be that your husband can follow a much more varried and larger diet or that your teenager and each absolute junk and still function fine and you cannot. Maybe there really are people that eat the way diet was portrayed on the Gilmore Girls, and look like the Gilmore Girls, but I am 100% certain I am not one of them. I’ll be following this up with a blog on the New Food Pyramid, and how we know what we know, but it’s a “tale as old as time, a song as old as rhyme” that eating a diet with as little processed food as possible centering around veggies and meats is a healthy diet.