Eating Walnuts Cut Diabetes Risk in Women

BOSTONEating two or more servings of walnuts a week is associated with a 21% and 15% lower risk of incident type 2 diabetes before and after adjusting for body mass index (BMI) respectively, according to a new study published in the Journal of Nutrition.

Walnuts contain the highest antioxidant levels of any nut and are rich in polyunsaturated fatty acids and have been shown to improve various cardiometabolic risk factors. Researchers at the Harvard School of Public Health investigated the association between walnut intake and incident type 2 diabetes in two large cohort studies: the Nurses Health Study (NHS) and NHS II. They followed 58,063 women aged 52 to 77 years in NHS (1998-2008) and 79,893 women aged 35 to 52 years in NHS II (1999-2009) without diabetes, cardiovascular disease or cancer at baseline.

Consumption of walnuts and other nuts was assessed every four years using validated food frequency questionnaires. Self-reported type 2 diabetes was confirmed by a validated supplemental questionnaire. They documented a total of 5,930 incident type 2 diabetes cases during a 10-year follow-up.

They found two or more servings (1 serving = 28 grams) of walnuts per week to be associated with a 21% and 15% lower risk of incident type 2 diabetes before and after adjusting for body mass index (BMI), respectively.

A 2009 study published in the European Journal of Clinical Nutrition found dietary fat can be manipulated with whole foods like walnuts, producing reductions in fasting insulin levels.