Eating nuts or peanut butter may help prevent type 2 diabetes, according to a study of over 83,000 women.

Scientists at the Harvard School of Public Health studied the eating habits of 83,818 female nurses aged between 34 and 59 years old, with no history of diabetes, cardiovascular disease or cancer. The participants completed a dietary questionnaire at the start of the survey in 1980. They were then followed up for 16 years, by which time 3,206 had developed type 2 diabetes. 

Some 85% of the 1.3 million people with diabetes in the UK suffer from type 2. Type 2 is a growing problem and is linked to obesity and cardiovascular disease. Previous studies have investigated the role of peanuts in the prevention of cardiovascular disease and obesity, but this study, the results of which have been published in the Journal of the American Medical Association, is the first to investigate the role that peanuts might play in the prevention of type 2 diabetes.

The researchers found that women who ate peanut butter five or more times a week had a 21% lower risk of developing type 2 diabetes compared to women who never or almost never ate peanut butter.

Martha Funnell, head of health care and education for the American Diabetes Association, warned that some brands of peanut butter may contain high amounts of sugar and fatty preserves, reported AP.

Funnell said the study’s message should be that nuts and peanut butter can be beneficial if they are eaten as an alternative to refined grains and foods high in saturated fats rather than in addition to them.