New Analysis Finds No Correlation Between Intake of Refined Grains and Type 2 Diabetes

A commentary just published in Mayo Clinic Proceedings presents data showing no evidence linking refined grain consumption with risk of developing type 2 diabetes (T2D).  Written by Glenn Gaesser, Ph.D., professor in the College of Health Solutions at Arizona State University, the commentary includes data from all published observational cohort studies that looked at the associations between refined grain intake and risk of T2D. Based on findings from 11 different populations of adults, totaling nearly 400,000 men and women, results revealed no relation between consumption of refined grains and risk of T2D.

These findings refute the commonly held belief that refined and non-whole grains can directly lead to T2D when consumed. Eating refined staple grain foods, such as breads, cereals, and pasta were not associated with T2D risk, and total grain intake was consistently associated with lower risk of T2D. Even in studies that included indulgent grain foods such as cakes, cookies, sweet rolls, and muffins in the refined grain food category, no association with T2D risk was observed. However, several studies included in the review indicated that high consumption of white rice may increase risk of T2D but appeared to be mainly in Asian populations.  

“While these findings may seem surprising after years of maligning grains, in particular refined grains, there is actually a simple explanation,” said Dr. Gaesser. “Much of the research linking refined grain consumption to T2D risk is based on dietary patterns, which typically categorizes refined grains along with red and processed meat, sugar-sweetened beverages, French fries, and high-fat dairy products. It is important to note the distinct difference between the higher-risk categories like red and processed meat and sugar-sweetened beverages, compared with the refined grains category, which is often mistakenly associated with the aforementioned contributors to T2D.”

Adds Dr. Gaesser: “It’s important to remember that most refined grains consumed in America are enriched with thiamin, riboflavin, niacin, iron, and folic acid, and include many other essential nutrients that help make up for nutritional deficiencies that can occur in some American diets.  Grains are much healthier than people give them credit for.”

“This study continues to provide evidence to what we have been saying for years: it is ok, and even healthy, to eat grains,” said Erin Ball, GFF’s Acting Executive Director. “Whether it is a bowl of fortified breakfast cereal, a whole grain sandwich at lunch or even a small cookie eaten as part of a celebration, grains enrich both our lives and our health.” 

The full commentary can be viewed here. This work was supported in part by the Grain Foods Foundation. For more information about the Foundation, research findings, and grain foods’ role in a healthful diet, visit