Whole Grain

From The Experts

Type Two Diabetes

A study recently published in the European Journal of Clinical Nutrition has found strong evidence for the role of wholegrains in the prevention and management of diabetes (Venn and Mann, 2004).7 The study examined current epidemiological and experimental research and found that people who included three or more serves of wholegrains each day were 20-30% less likely to develop Type 2 diabetes. Authors also found that wholegrains can help control glycaemic responses, a key component of diabetes management. The authors concluded that promoting consumption of wholegrain foods, along with fruits, vegetables and legumes, is beneficial for the people with diabetes, and for the general population.

The Nurses’ Health Study is a large study which followed over 161,000 women over 12-18 years. After assessing dietary intake it was shown that wholegrain intake was inversely associated with type 2 diabetes. Of the women that consumed either moderate or high amounts of wholegrains there was at least a 17% reduction in the incidence of type 2 diabetes. When looking at different parts of the grain it was shown that bran had a more protective effect than the germ (de Munter et al., 2007).1 The bran is often removed during the refining process, so wholegrains are a better source of bran than refined grains.

Breakfast cereals are a major source of wholegrains in many people’s diets. A study looking at the association between breakfast cereal consumption and diabetes showed those that eat breakfast cereals have lower risk of type 2 diabetes. This reduction in risk was strongest in wholegrain cereals and weakest in refined cereals. The more times a week wholegrain cereals were eaten the stronger the association (Kochar et al., 2007).3

A study which looked at individual’s at risk of developing type 2 diabetes showed those that were given a wholegrain-based dietary product had lower fasting insulin and insulin resistance compared to individuals that were put on a non-wholegrain dietary product. It was suggested that the insoluble dietary fibre in the wholegrains helped improve the insulin profile and reduce the risk of developing type 2 diabetes (Rave et al., 2007).5

There are many different causes linked to type 2 diabetes. The increased intake of refined carbohydrates is one possible cause and fits with statistics that show type 2 diabetes incidence has increased in parallel with our increased intake of processed grains, soft drinks and refined flours. Gross et al. (2004) has shown a strong association between our increase in corn syrup and refined grains and decrease in fibre and the increased in type 2 diabetes. It has been suggested that we can decrease our risk of type 2 diabetes by replacing our intake of these highly refined carbohydrates with a less processed wholegrain alternative.

A recent review of 12 studies all showed that wholegrain consumption decreases the risk of type 2 diabetes, while refined grains increased the risk. It was suggested that the fibre in wholegrains play an important role in reducing type 2 diabetes incidence (Okarter and Liu, 2010).4

Because of the growing evidence supporting the role of wholegrains in the prevention and management of diabetes, encouraging wholegrains is now recommended as a core component of health promotion messages. A study published by Schulze and Hu (2005), emphasises the need to encourage people to replace refined grain products with whole grains, as part of health promotion strategies for targeting diabetes. Along with physical activity, replacing saturated and trans fats with unsaturated fats, moderating alcohol consumption and maintaining a healthy body weight, including wholegrains has been identified as a crucial element in diabetes prevention.

References

  1. DE MUNTER, J. S. L., HU, F. B., SPIEGELMAN, D., FRANZ, M. & VAN DAM, R. M. 2007. Whole grain, bran, and germ intake and risk of type 2 diabetes: a prospective cohort study and systematic review. PLoS Medicine / Public Library of Science, 4, e261.
  2. GROSS, L. S., LI, L., FORD, E. S. & LIU, S. 2004. Increased consumption of refined carbohydrates and the epidemic of type 2 diabetes in the United States: an ecologic assessment. American Journal of Clinical Nutrition, 79, 774-9.
  3. KOCHAR, J., DJOUSSE, L. & GAZIANO, J. M. 2007. Breakfast cereals and risk of type 2 diabetes in the Physicians' Health Study I. Obesity, 15, 3039-44.
  4. OKARTER, N. & LIU, R. H. 2010. Health benefits of whole grain phytochemicals. Critical Reviews in Food Science & Nutrition, 50, 193-208.
  5. RAVE, K., ROGGEN, K., DELLWEG, S., HEISE, T. & TOM DIECK, H. 2007. Improvement of insulin resistance after diet with a whole-grain based dietary product: results of a randomized, controlled cross-over study in obese subjects with elevated fasting blood glucose. British Journal of Nutrition, 98, 929-36.
  6. SCHULZE, M. B. & HU, F. B. 2005. Primary prevention of diabetes: what can be done and how much can be prevented? Annual Review of Public Health, 26, 445-67.
  7. VENN, B. J. & MANN, J. I. 2004. Cereal grains, legumes and diabetes. European Journal of Clinical Nutrition, 58, 1443-61.