Eating Walnuts can help Improve Quality of Diets, Study Says
Eating a moderate amount of walnuts everyday can improve one's overall diet, a new study reported.
"We know nuts are really nutritious, but they're really loaded with calories. So the 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?" Dr. David Katz, lead author and the founding director of the Yale-Griffin Prevention Research Center in Derby, Connecticut, said to Live Science.
For this study, the researchers recruited 112 (31 men, 81 women) participants, who were divided into two groups. The first group followed a diet with the help of counseling that was geared at reducing caloric intake and the second group did not get any help.
The two groups were then divided into two more groups each based on walnut consumption. One group ate two ounces of walnuts per day where as the other group did not eat any walnuts at all. The researchers reversed the dietary interventions at the three-month point. The participants were between the ages of 25 and 75, and they were all considered high-risk for type 2 diabetes.
The researchers recorded the participants' height, weight, body mass index (BMI), blood pressure, cholesterol, fasting blood glucose and glycated haemoglobin (HbA1c) as well as their food intake at the start of the study and then after three, six, 12 and 15 months.
The researchers found that people who ate walnuts had improved blood vessel cell wall function. They also experienced improvements in their bad cholesterol. A walnut-rich diet did not seem to affect blood pressure, blood glucose, fasting blood glucose or good cholesterol levels. HbA1c increased in all of the groups. People who were not on the walnut diet also had improvements in their cell wall function and cholesterol levels.
The team also found that people who ate walnuts but did not receive diet counseling saw an increase in their body fat. In the walnut-group with counseling, the participants finished the study with smaller waist circumference.
"Our data suggest that inclusion of walnuts in the diet, with or without dietary counselling to adjust caloric intake, improved diet quality and may also improve [endothelial function], and reduce total and LDL cholesterol in this sample of adults at risk for diabetes," conclude the researchers.
Walnuts are a great source of fatty acids, folate, vitamin E and other nutrients.