Eating more unsaturated fats instead of carbohydrates decreases the risk of developing type 2 diabetes, says research based on new meta-analysis, published in PLOS Medicine.

The team under Senior author Dr. Dariush Mozaffarian, dean of the Friedman School of Nutrition Science and Policy at Tufts University in Medford, MA, and first author Fumiaki Imamura, of the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, United Kingdom, looked at data for 4,660 adults that had been collected in 102 studies. In the randomized, controlled trials, the adults were given meals containing various types and quantities of carbohydrate and fat.

The researchers examined how these variations in diet impacted measures of metabolic health, and specifically, how saturated, monounsaturated and polyunsaturated fats and carbohydrates impact the development of type 2 diabetes. The study focused on key biological markers of glucose and insulin control like blood sugar, blood insulin, insulin resistance and sensitivity, and how well the body was able to produce insulin in response to blood sugar.

Results suggested that consuming foods rich in monounsaturated fat or polyunsaturated fat had a positive effect on blood glucose control, compared with consumption of dietary carbohydrate or saturated fat. For each 5 percent of dietary energy that was switched from carbohydrates or saturated fats to mono- or polyunsaturated fats, they found a drop of around 0.1 percent in HbA1c - a blood marker of long-term glucose control.

Previous research has suggested that for each 0.1 percent decrease in HbA1c, the incidence of type 2 diabetes drops by 22 percent and the chance of developing cardiovascular diseases falls by 6.8 percent. Imamura notes that replacing carbohydrates and saturated fats with polyunsaturated fats appears to be consistently beneficial. Imamura adds: "This is a positive message for the public. Don't fear healthy fats." This is the first time a team has systematically reviewed all the available evidence measuring the effects of carbohydrate and different kinds of fat in the diet.

Read More