A handful of walnuts not only makes for a good snack, it also helps lower risk factors for type 2 diabetes and gets people started on a healthier diet, as revealed by a new study.
In this new research, subjects given walnuts daily for six months saw their blood vessel function improve and their levels of LDL or “bad” cholesterol decrease – two risk factors for type 2 diabetes.
The findings were published in the journal BMJ Open Diabetes Research & Care.
Lead study author Dr. David Katz, also Yale-Griffin Prevention Research Center founding director, acknowledged that while walnuts are rich in essential fatty acids (EFAs) and other vital nutrients, they are also high in calories.
“[T]he question was, if we tell people to eat nuts every day, will they over time start to gain weight? And will weight gain over time start to offset the metabolic benefits that come from the high-quality nutrition of nuts?" said Dr. Katz in an interview.
The team analyzed 81 women and 31 men, from ages 25 to 75, who were high-risk for type 2 diabetes. They were assigned to two groups: one that received two ounces of walnuts alongside their regular diet, and another that didn't receive any.
After the six-month period, a 12-week break followed and the two groups were switched. The team then assessed the subjects’ height and weight, body mass index (BMI), waist circumference, quality of diet, cholesterol and glucose status, blood pressure, and blood vessel functioning via ultrasound.
Participants who consumed walnuts saw their blood vessel function and overall diet quality improve, regardless of the diet counseling they received.
Adding walnuts also did not affect blood pressure or HDL (“good”) cholesterol levels. While blood glucose tended to rise notwithstanding dietary advice, waist circumference reduced substantially when the walnut diet was paired with calorie restriction advice.
Dr. Katz explained that people seemed to “do pretty well” and did not gain weight considerably even without being told to make room for the calories. “[But] you may be able to augment those benefits if you do provide some counseling about how to make room for those calories,” he added.
He reminded that in the walnut-rich diet group, participants without calorie restriction counseling had increased body fat, compared to those who were counseled about lowering calorie consumption.
The study received was funded by the California Walnut Commission.
New York State Academy of Nutrition’s Anita Mirchandani called for people to be aware of all fat sources in their diet.
“It is recommended that 20-35 percent of total calories per day come from fats,” she reminded, citing as an example that for those on an 1,800-calorie diet every day, 40 to 70 grams of fat are ideal.
Photo: Erich Ferdinand | Flickr