Whole grains - regardless of type - are important for preventing type 2 diabetes
A new comprehensive study from researchers at Chalmers University of Technology and the Danish Cancer Society Research Center strongly confirms previous research findings on the importance of whole grains for prevention of type 2 diabetes. The link has been known for a long time but the role of different cereals and cereal products remain unclear.
The study was large, comprising 55,000 participants, with a long median follow-up time of 15 years. The main finding was that it made no difference which type of whole grain product or cereal the participants ate - ryebread, oatmeal, and muesli, for example. All seem to offer similar protection against type 2 diabetes. More important is the amount of whole grain that is consumed each day and the study provides important clarification when it comes to daily intakes associated with lowered risk of developing type 2 diabetes. The participants were divided into 4 different groups, based on how much whole grain they reported eating. Those with the highest intak reported that they ate at least 50 grams of whole grain each day. The development of type 2 diabetes was lowest in this group. In the group with the highest whole grain intake, the diabetes risk was 34 percent lower for men, and 22 percent lower for women, than in the group with the lowest wholegrain intake.
The researchers were surprised that the diabetes risk did not appear to differ between whole grains.
'We hypothesized that whole grain rye and oats would show larger risk reduction compared to whole grain wheat', Professor Rikard Landberg says. 'Rye is the cereal with the highest amount of dietary fibre and it also contains a mixture of fibres with different functionalities compared to wheat and whole gain oats contains dietary fibre that have been shown to beneficially affect blood lipids and glucose levels after a meal. One reason could be that questionnaires used for participants to report their intakes are not precise enough to estimate specific grain intakes', says Landberg.
The study design did not allow the researchers to investigate why whole grain foods appears to lower the risk of developing type 2 diabetes.
'We need more mechanistic studies on the physiological effects of whole grain foods where we use modern techniques and also take gut microbiota and the fact that individuals may respond differently to specific food intakes', Landberg concludes.