In the previous post, I mentioned an article by science writer Gary Taubes which revealed the source of many of the plausible yet bad ideas in the nutrition world. This source is the field of epidemiology (the study of how disease spreads and can be controlled*) and specifically the prospective or cohort study. In these studies, large populations are given questionnaires which assess for all kinds of factors like diet, physical activity and prescription drug use. The group is then followed for a number of years and assessed for disease development and other factors of health looking for associations between habits and disease or wellness. Taubes shows in the article how epidemiology was developed to study infectious disease epidemics but is very poor at elucidating the complex causes of chronic disease. The cohort study can show association but never causation. Consider all the flip flop studies reported in the media over the years. Is coffee good for you or bad for you? What about hormones in post-menopausal women? Low fat vs. Low carb vs. cutting calories for weight loss? Vitamin E for better heart health? This article allowed me to see that a misplaced faith in epidemiology was the cause of massive confusion regarding diet. It explained why so many smart people could believe something about diet which had no connection to well understood basic science. At the end of the article, the editors made note that Taubes had a new book out entitled “Good Calories/Bad Calories”. Although eager to read the book, I had no idea what a game changer it would be. More next week.
*Definition provided by Merriam-Webster.com