Refining Diet-based Approaches to Lowering Type 2 Diabetes Risk

By Brittain Whiteside-Galloway
Thursday, December 1, 2016

Not all plant-based foods provide equal benefit in terms of reducing risk of diabetes, a new Harvard study finds.

Researchers assessed the link between plant-based dietary patterns and lower risk of Type 2 diabetes. A team led by Ambika Satija, ScD, postdoctoral fellow in Nutrition at Harvard T.H. Chan School of Public Health, and Frank Hu, MD, PhD, Professor of Medicine at Harvard Medical School and Professor of Nutrition at the School of Public Health, analyzed data from three prospective cohort studies that followed more than 200,000 U.S. health professionals for more than two decades.

Published in PLOS Medicine, the study found that eating a predominantly plant-based diet reduced the risk of developing Type 2 diabetes by roughly 20 percent. Consuming a version of this diet focused on healthful plant foods such as fruits, vegetables, nuts, legumes and whole grains was linked to a 34 percent lower risk of Type 2 diabetes. However, a plant-based diet high in foods such as potatoes, refined grains, and sugar-sweetened beverages and fruit juices was linked to a 16 percent greater risk.

The study adds definition to scientists’ understanding of food choices that may stave off diabetes and helps redirect that conversation, according to the researchers.

“[Because] not all plant-based foods are created equal, when we talk about a plant-based diet, we should put more emphasis on high-quality or healthy plant-based foods,” Dr. Hu adds.

Quantifying Benefits

Reducing diabetes risk significantly did not require a radical dietary overhaul.

“It’s important to emphasize we’re not talking about drastic changes in people’s diets,” Dr. Hu says. “We’re not talking about becoming vegetarian or vegan — we’re talking about moderate changes.”

Participants reduced but did not eliminate meat from their diets, Satija notes. On average, participants who loosely adhered to a plant-based diet had five to six servings of animal-based foods per day; stricter adherents had about four servings per day.

“Though the difference between daily servings wasn’t much, the difference in reduction of Type 2 diabetes risk between the two groups was substantial,” Satija says. “You don’t have to make extreme changes to see a substantial reduction in risk of Type 2 diabetes.”

A Distinction

As with plant foods, not all animal-based foods carry equal potential for greater risk of Type 2 diabetes.

“Fish and seafood, for example, are healthy sources of protein that are not linked to increased risk of diabetes, ... unlike red and processed meats,” says Christine McKinney, RD, CDE, clinical nutritionist and diabetes specialist with Johns Hopkins Bayview Medical Center in Baltimore, who was not involved in the study.