PLOS ONE HAS PUBLISHED (Feb. 27) a major study on the linkage between dietary-intake of sugar and the development of type 2 diabetes.

The Relationship of Sugar to Population-Level Diabetes Prevalence: An Econometric Analysis of Repeated Cross-Sectional Data Sanjay Basu, Paula Yoffe, Nancy Hills, Robert H. Lustig Research Article | published 27 Feb 2013 | PLOS ONE 10.1371/journal.pone.0057873

“ABSTRACT: While experimental and observational studies suggest that sugar intake is associated with the development of type 2 diabetes, independent of its role in obesity, it is unclear whether alterations in sugar intake can account for differences in diabetes prevalence among overall populations. Using econometric models of repeated cross-sectional data on diabetes and nutritional components of food from 175 countries, we found that every 150 kcal/person/day increase in sugar availability (about one can of soda/day) was associated with increased diabetes prevalence by 1.1% (p ,0.001) after testing for potential selection biases and controlling for other food types (including fibers, meats, fruits, oils, cereals), total calories, overweight and obesity, period-effects, and several socioeconomic variables such as aging, urbanization and income. No other food types yielded significant individual associations with diabetes prevalence after controlling for obesity and other confounders. The impact of sugar on diabetes was independent of sedentary behavior and alcohol use, and the effect was modified but not confounded by obesity or overweight. Duration and degree of sugar exposure correlated significantly with diabetes prevalence in a dose-dependent manner, while declines in sugar exposure correlated with significant subsequent declines in diabetes rates independently of other socioeconomic, dietary and obesity prevalence changes. Differences in sugar availability statistically explain variations in diabetes prevalence rates at a population level that are not explained by physical activity, overweight or obesity.”

Readers are also directed to Mark Bittman’s New York Times Op-Ed, published on February 28, 2013, in which Bittman discusses the PLOS ONE study.

We are pleased to see Bittman’s reference to this study meeting the famous “Bradford-Hill criteria:

“The study controlled for poverty, urbanization, aging, obesity and physical activity. It controlled for other foods and total calories. In short, it controlled for everything controllable, and it satisfied the longstanding “Bradford Hill” criteria for what’s called medical inference of causation by linking dose (the more sugar that’s available, the more occurrences of diabetes); duration (if sugar is available longer, the prevalence of diabetes increases); directionality (not only does diabetes increase with more sugar, it decreases with less sugar); and precedence (diabetics don’t start consuming more sugar; people who consume more sugar are more likely to become diabetics).”

This author has long believed that an understanding of the Bradford-Hill criteria is fundamental to the developing the ability to distinguish meaningful and significant association in the evaluation of scientific studies in the biological sciences.

Please see our essay on “Causation in Law and Association in Science” on our Essays Pages. (Jan. 24, 2012). Readers will find a PDF file of the famous Bradford-Hill paper which we consider “must-reading” for Regulatory Science Professionals. 

Austin Bradford Hill, “The Environment and Disease: Association or Causation?,”Proceedings of the Royal Society of Medicine, 58 (1965), 295-300.

Because this author believes that both the United States and the European Union will, in due course, adopt mandatory food labeling for added (as opposed to  naturally occurring) sugar, we also have added Michael Moss’ recently published book to our list of the Best Science Books of the past decade which we maintain on our Essays Pages.

Moss, Michael, “Salt Sugar Fat: How the Food Giants Hooked Us”, Random House, 2013.