Daily Handful of Walnuts Linked to Better Diet and Improvements in Some Health Risk Factors
What to Know
Walnuts boast numerous nutritional benefits. They’re a rich source of essential fatty acids, folate, vitamin E and other nutrients, and they appear to be good for the heart. However, they pack a lot of calories. Can walnuts be part of a healthy diet for people with diabetes without contributing to weight gain?
Researchers recruited 31 men and 81 women between the ages of 25 and 75. All were at high risk of developing diabetes. Randomly divided into two groups, half followed a reduced-calorie diet accompanied by counseling designed to curb calorie consumption, while the other group were assigned a reduced-calorie diet without counseling. Within each group, half were randomly selected to include 2 ounces of walnuts in their daily diet for six months; the other half were told not to eat walnuts. At intervals, for 15 months, researchers measured the participants’ weight, blood pressure, blood glucose levels, cholesterol, and other health markers.
By the end of the study, participants who ate walnuts had lower total and “bad” (LDL) cholesterol and improved blood vessel function, both of which are risk factors associated with type 2 diabetes. In addition, although high in calories, walnuts were not associated with weight gain in the study. And while body fat increased in the group that did not restrict their calories, waist circumference—an important marker of health risks—went down in those who did curb calories. Walnuts had no impact on blood pressure, blood glucose levels, or "good" (HDL) cholesterol, regardless of dietary counseling.
If you’re at risk for diabetes, one daily handful of walnuts—no more!—may lower your chances of developing diabetes by improving your diabetes risk factors. It also may help improve your overall diet. Be aware that this study included many more women than men, and it was not very diverse. It’s unclear whether these results would apply to all types of people.
Walnut ingestion in adults at risk for diabetes: effects on body composition, diet quality, and cardiac risk measures. BMJ Open Diab Res Care 2015;3:e000115; http://dx.doi.org/10.1136/bmjdrc-2015-000115