Are anti-sugar studies bunk, or is the sugar lobby busted?
A systematic review of previous research informing daily sugar intake, published Monday in Annals of Internal Medicine, concludes “guidelines on dietary sugar do not meet criteria for trustworthy recommendations and are based on low-quality evidence.”
Meanwhile, an editorial published alongside the review blows the whistle on the study’s funding source. The International Life Sciences Institute (ILSA North America) is a trade group representing The Coca-Cola Company, Dr. Pepper Snapple Group, The Hershey Company, Mars, Inc., Nestle USA and PepsiCo, among others.
The study was conducted by authors representing University of Minnesota, McMaster University and The Hospital for Sick Children Research Institute and University of Toronto in Canada, and Kerman University of Medical Sciences in Iran.
The authors arrived at their conclusion after combing through previous peer-reviewed research from 1995 to 2016 found in MEDLINE, EMBASE and Web of Science databases, as well as “gray literature” which it lists as “bibliographies, Google and experts.”
Per the U.S. Centers for Disease Control and Prevention, “Americans should keep their intake of added sugars to less than 10 percent of their total daily calories as part of a healthy diet. For example, in a 2,000-daily calorie diet no more than 200 calories should come from added sugars.”
One can of Coke contains about 140 calories from sugar.
The authors of the review wrote, “The guidelines scored poorly on AGREE II criteria, specifically in rigor of development, applicability, and editorial independence. Seven recommendations provided nonquantitative guidance; five recommended less than 25 percent to less than 5 percent of calories from nonintrinsic sugars.”
In other words, the authors argued that most of the data informing daily sugar intake was inconsistent in terms of thresholds and methodology. “Public health officials (when promulgating these recommendations) and their public audience (when considering dietary behavior) should be aware of these limitations.”
Not so fast, say the authors of the accompanying editorial, a medical doctor and a dentist from the University of California, San Francisco.
“The guidelines examined were issued between 1995 and 2016; one would expect recommendations spanning more than two decades to evolve as scientific knowledge evolved,” they wrote. “The most recent guidelines from Public Health England, World Health Organization, and the U.S. Department of Agriculture show remarkable consistency, recommending limits ranging from less than 5 percent to less than 10 percent of daily calories from sugar intake.”
As for using AGREE II as a yardstick, the editorial writers argued, “AGREE II is designed for clinical practice guidelines in the treatment of illness. The objective of dietary guidelines is to assess risk of consumption at the population level, not to evaluate interventions to reduce consumption. Using this tool, the authors downgraded the trustworthiness of guidelines because ways to limit sugar intake ‘were not clearly presented’ and because ‘likely barriers and facilitators of implementation’ were not discussed.”
The authors of the editorial noted that many years ago, the tobacco industry made similar arguments in trying to debunk the dangers of secondhand smoke.