Eating 2 Servings of Walnuts a Week Linked to Healthy Aging Process

A new study revealed that eating 1-2 servings of walnuts per week (1/4 cup per serving) could lower incidence of physical function impairment in women, resulting to a more healthy aging process.

Walnuts contain polyunsaturated fat (13 grams per ounce) including the plant-based omega-3 fatty acid alpha-linolenic acid (ALA). Walnuts are also the only nut to contain a significant amount of ALA with 2.5 grams per one ounce serving.

The study, published in The Journal of Nutrition, look into the linked between overall diet quality and reduced risk of physical function impairment. These overall diet qualities include higher consumption of fruits and vegetables, reduced intake of sugar-sweetened beverages, trans fat, and sodium and moderate alcohol intake.

For the study, researchers analyzed the data of 54,762 women in the Nurses' Health Study, which tracked women for over 30 years. These women were asked about their physical function, which includes their ability to perform basic daily activities. Researchers assessed the diet of each women using the Alternative Healthy Eating Index (AHEI-2010), which measures the diet quality, but incorporating foods and nutrients predictive of chronic disease risk based on scientific evidence.

The researchers then discovered that participants in the higher quintiles of AHEI-2010 were less likely to experience incidence of physical function impairment. Aside from walnuts, top contributors to the food components of AHEI-2010 include oranges, orange juice, apples and pears and romaine or leaf lettuce.

"These results add to the large body of evidence that outline the many benefits of a healthy diet for women. Additional research is needed to better understand how diet and lifestyle choices can help maintain our health and well-being as we age," said Dr. Francine Grodstein, ScD, professor of medicine at Brigham and Women's Hospital and Harvard Medical School and co-author of the study, in a statement.

However, researchers noted that several limitations of the study should be considered before interpreting their result. First, the study was only conducted in women, making the results not generalizable to men. Also, the study is purely observational and no causal effect can be traced due to possible human error in the part of the participants, which means the participants may have misreported their dietary intake.