Dr David J A Jenkins, of St. Michael's Hospital and the University of Toronto, and colleagues found that a diet high in food with a low glycemic index, such as nuts, beans and lentils, was associated with better glycemic control and improved coronary heart disease risk factors than a diet that emphasized high cereal whole grains diet.

They conducted randomized, controlled, parallel study, with 210 type 2 diabetes patients who were being treated with antihyperglycemic drugs and assigned them to either receive advice on a high cereal fibre diet like” brown" or whole grain foods such as whole grain bread, whole grain breakfast cereal, brown rice,

potatoes with skins, whole wheat bread and crackers or a low glycemic index diet like beans, peas, lentils, pasta, rice boiled briefly, low glycemic index bread such as pumpernickel, rye pitta, and quinoa and flaxseed, and cereals such as large flake oatmeal and oat bran. Each patient was on one of the diets for 6 months during the period September 2004 to May 2007. Both diets also emphasized fruit and vegetables.

Each patient's blood was tested for blood glucose and cardiovascular risk factors before and after they went on the diet.

.The researchers found that HbA1c level (average blood sugar) went down by 0.5 per cent absolute units in the low-glycemic diet compared to 0.18 decrease in the high-cereal fibre diet.

There was an increase of high-density lipoprotein (HDL) cholesterol of 1.7 mg/dL, and a decrease of HDL-C in the high-cereal fibres diet of 0.2 mg/dL.
There was a greater reduction in the ratio between "bad" cholesterol (low density lipoprotein cholesterol or LDL-C) and good cholesterol (LDL -C: HDL-C) in the low-glycemic index diet group compared with the high-cereal fibres diet group.

The authors concluded: "In patients with type 2 diabetes, 6-month treatment with a low-glycemic index diet resulted in moderately lower HbA1c levels compared with a high- cereal fibre diet."

One important point to note is that high fat food items like ice creams also come under Low-glycemic index diet, but are not recommended for diabetes patients due to their high fat content.

Sources: JAMA