Fibre, magnesium may slash diabetes risk
risk of developing diabetes by more than 25 per cent, suggests a
new study from Germany.
Writing in the Archives of Internal Medicine, the researchers report consumption of 29 grams of fibre per day results in a 27 per cent lower risk of developing diabetes, compared to consumption of 15.1 grams per day. "The evidence from our study and previous studies, summarized by means of meta-analysis, strongly supports that higher cereal fibre and magnesium intake may decrease diabetes risk," wrote lead author Matthias Schulze, from the German Institute of Human Nutrition Potsdam-Rehbruecke. "Whole-grain foods are therefore important in diabetes prevention." An estimated 19 million people are affected by diabetes in the EU 25, equal to four per cent of the total population. This figure is projected to increase to 26 million by 2030. In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132bn, with $92bn being direct medication costs, according to 2002 American Diabetes Association figures. The new study involved a prospective study of about 25,000 subjects (9,702 men and 15,365 women) with an average age of 49.6 years. The study population was part of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam. Diets were assessed using a semi-quantitative 148-item food frequency questionnaire (FFQ) and studied for an average of seven years, during which time 844 incident cases of type-2 diabetes were diagnosed. Schulze and co-workers calculated that consumption of fibre through cereal, bread and other grain products (cereal fibre) was associated with a reduced risk of diabetes. Those with the highest fibre intake (an average of 29 grams per day) were calculated to have a 27 per cent lower risk than those with the lowest intake (an average of 15.1 grams per day). No difference in the reduction of risks was observed between soluble or insoluble fibre, said the researchers, and no significant effect was observed for fruit and vegetable intake or magnesium, as calculated from the FFQs. The researchers also conducted a meta-analysis of nine studies of fibre and eight studies of magnesium intake. After pooling the data, Schulze and co-workers report that the highest consumption of cereal fibre was associated with a 33 per cent reduction in the risk of diabetes, while those who consumed the most magnesium had a 23 per cent lower risk, compared to those who consumed the least. Again, no association was found between fruit or vegetable fibre and diabetes risk. "Our meta-analysis showed a significant inverse association between magnesium intake and the risk of type-2 diabetes," wrote the authors. "Still, magnesium intake was not related to diabetes risk in EPIC-Potsdam." The role of magnesium is still controversial, but other studies have proposed reasons for why the mineral may reduce the risk of developing diabetes. Low magnesium levels (hypomagnesemia) have been linked to lower activity of insulin receptors, reducing the effectiveness of insulin and leading to insulin resistance. Commenting independently on the research, Tracy Kelly, care advisor at British charity Diabetes UK, told NutraIngredients.com: "The results of this study are interesting. Obviously, food containing fibre and magnesium are important elements of a good diet. In addition, fibre helps to lower cholesterol levels, which is important in terms of Type 2 diabetes risk. However, these elements alone will not stop someone from developing the condition." Kelly said that the charity would continue to recommend a healthy, balanced diet and regular physical activity to reduce the risk or delay the onset of the condition. Source: Archives of Internal Medicine 2007, Volume 167, Pages 956-965. "Fiber and Magnesium Intake and Incidence of Type 2 Diabetes: A Prospective Study and Meta-analysis" Authors: M.B. Schulze, M. Schulz, C. Heidemann, A. Schienkiewitz, K. Hoffmann, H. Boeing