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Whole grains prevent type 2 diabetes

Consuming 16 g of whole grains, including rye, oat or wheat cereals, per day was associated with a reduced risk for type 2 diabetes, according to findings published in The Journal of Nutrition.

“Type 2 diabetes is a major health concern worldwide,” Cecilie Kyrø, MSc, PhD, from the Danish Cancer Society Research Center, Copenhagen, Denmark, and colleagues wrote. “Whole grains and cereal fiber may offer protective effects on type 2 diabetes risk. However, few studies have been conducted in cohorts with detailed information on whole-grain cereal intakes and product types and with wide ranges of intake.”

Kyrø and colleagues analyzed data from the Danish Diet, Cancer and Health cohort to examine how whole grain intake affects the risk of type 2 diabetes. A total of 55,465 adults aged between 50 and 65 years were included in the study and completed a food-frequency questionnaire on total whole grain intake including different cereal products and types.

Participants were divided into four groups based on whole grain intake. Men (n = 26,251) with the lowest intake of whole grains consumed 27 g or less per day and those with the highest intake consumed 60 g or more per day, whereas women (n = 29,214) with the lowest intake of whole grains consumed 24 g or less per day and those with the highest intake consumed 50.8 g or more per day.

During follow-up (median, 15 years), 7,417 participants were diagnosed with type 2 diabetes.

The researchers found that each whole grain serving of 16 g per day lowered the risk for type 2 diabetes by 11% among men (HR = 0.89; 95% CI, 0.87-0.91) and by 7% among women (HR = 0.93; 95% CI, 0.91-0.96).

All whole grain cereal types studied, including wheat, rye and oats, were significantly associated with reduced type 2 diabetes risk among men. However, only wheat and oats were significantly associated with a reduced risk among women.

Different whole-grain products, rye bread, whole-grain bread and oatmeal/muesli appeared to significantly lower the risk for type 2 diabetes among both men and women.

Participants who consumed the most whole grains (at least 50 g per day) had the lowest risk for type 2 diabetes. The highest consumption of whole grains was associated with a 34% lower risk for type 2 diabetes among men and a 22% lower risk among women, compared with the lowest whole grain consumption.

“Our results are in line with dietary advice, which recommends switching out foods containing white flour for whole grains,” Rikard Landberg, MSc, PhD, senior author of the study and professor in food and health at Chalmers University of Technology, Gothenburg, Sweden, said in a press release. “You get extra health benefits — white flour has some negative effects on health, while whole grain has several positive effects, beyond protection against type 2 diabetes.”

“When it comes to whole grains, the research results are clear: among the many studies which have been made, in varied groups of people around the world, there hasn't been a single study which has shown negative health effects,” he added. – by Alaina Tedesco

Disclosure: The authors report no relevant financial disclosures.