Written by Jessicca Patella, ND. A large study of 58,063 women aged 52-77 and 79,893 women aged 35-52 has determined that consumption of walnuts lowers risk of diabetes. After 10 years, the participants consuming 1 serving per week of walnuts had a 15% lower risk of type-2 diabetes and those consuming 2 or more servings had a 21% lower risk of type-2 diabetes.
Type 2 diabetes is a major public health concern, affecting an estimated 25.6 million American adults and 366 million people worldwide (2,3). Type 2 diabetes is the most common form of diabetes, making up approximately 90% of all diabetes cases (1). The main ways to help prevent type 2 diabetes are through diet and lifestyle changes and research shows the type of fat intake plays a role in the development of the disease (1,4). Recent research has found that consuming walnuts is associated with a lower risk of type 2 diabetes in women (1).
Walnuts are unique from all other nuts because they contain some of the highest levels of polyunsaturated fats, up to 47% in weight (1,5). Research has shown that diets lower in trans and saturated fats and higher in monounsaturated and polyunsaturated fats are associated with a lower risk of type 2 diabetes (1,4).
The recent research included women from two large cohort studies: the Nurses’ Health Study (NHS) and Nurses’ Health Study II (NHS II)(1). A total of 58,063 women aged 52-77 were in the NHS group (1998-2008) and a total of 79,893 women aged 35-52 were in the NHS II group (1999-2009). All of the women were free of diabetes, cardiovascular disease and cancer at baseline. Consumption of nuts, including walnuts, was part of a 130-food item food questionnaire, given every 4-years, to determine food intake (1).
After 10 years, a total of 5930 women developed type 2 diabetes, 3166 in the NHS group and 2764 in the NHS II group (1). The more walnuts consumed, the lower the risk of diabetes (1). Participants consuming 1 serving per week of walnuts had a 15% lower risk of type 2 diabetes (1 serving =28 grams or 1 ounce), and participants consuming 2 or more servings per week had a 21% lower risk of type 2 diabetes (1).
Women who ate walnuts more frequently tended to be older, weigh less, exercise more and smoke less. Women who consumed more walnuts also tended to eat more fish, whole grains, fruit and vegetables than those who rarely consumed nuts (1). Therefore, more nut consumption was also associated with multiple markers for an overall healthy lifestyle (1).
In conclusion, frequent intake of walnuts was associated with a lower risk of diabetes in women. This was a large study over multiple regions, but further studies are needed to get a better understanding of the association. Because women who consumed more walnuts also tended to have markers of a healthier lifestyle, the effects of walnuts on diabetes needs to be studied independently.
Source: Pan, An, et al. “Walnut consumption is associated with lower risk of type 2 diabetes in women.” The Journal of nutrition 143.4 (2013): 512-518.
© 2013 American Society for Nutrition.
Posted March 13, 2013.
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
References:
- Pan A, et al. Walnut Consumption is Associated with Lower Risk of Type 2 Diabetes in Women. 2013 J. Nutr. doi: 10.3945/jn.112.172171
- Centers for Disease Control and Prevention. Internet. National diabetes fact sheet; 2011
- International Diabetes Federation. IDF diabetes atlas. 5th ed
- Rise ́rus U, et al. Dietary fats and prevention of type 2 diabetes. Prog Lipid Res. 2009;48:44–51.
- USDA ARS, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference.
