High fibre diets bad for controlling diabetes, heart disease
A Canadian study found that beans, peas, pasta, lentils and boiled rice are healthier for controlling type-2 diabetes and heart disease risks than high-fibre diets like cereals and whole grain bread.
The study "Effect of a Low Glycemic Index or a High Cereal Fibre Diet on Type-2 Diabetes: A Randomized Trial" has found that these foods are better at managing glycemic control for type-2 diabetes and risk factors for coronary heart disease than high-fiber diets.
Professor David Jenkins of Toronto-based St. Michael’s Hospital, who led the study, said their research assumes importance as the incidence of type-2 diabetes is likely to double in the next 20 years.
"Our study shows that a low GI (glycemic index) diet can also minimise the risk factors associated with cardiovascular disease. It does this better than a diet high in fiber, but with a higher GI," he said.
GI is a measure for calculating the glucose level of the blood. A low GI diet contains foods that have a low glucose level.
"Pharmaceuticals used to control type-2 diabetes have not shown the expected benefits in terms of reducing cardiovascular disease. Our hope is that the low GI diet may help all the complications of diabetes," he added.
As part of their study, Jenkins and his team picked up 210 patients with type-2 diabetes and divided them into two groups for diet treatment.
They compared the effects of a low GI diet versus a high-fibre diet on glycemic control and cardiovascular risk factors for these patients for a period of six months.
After the six-month diet treatment, the researchers found that the hemoglobin level (blood glucose level) decreased by -0.50 percent in the group that was served the low glycemic index diet.
On the other hand, it decreased by only -0.18 percent in the group that was served the high cereal fibre diet, clearly indicating that high-fibre diets were not good for type-2 diabetes patients.
In relation to the effects of these two set of diets in heart stroke control, the researchers observed the ratio of high-density lipoprotein cholesterol (HDL-C) and the low-density lipoprotein cholesterol (LDL-C).
They found that the ratio showed a greater reduction in the low glycemic index diet group compared with the high-fibre diet group, showing the latter group was at higher risk of heart stroke.
The findings have been published in the Dec 17 issue of Journal of the American Medical Association.