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Increasing daily intake of walnuts has been linked to lower cholesterol levels, overall weight, and quality of diet.
Increasing daily intake of walnuts has been linked to lower cholesterol levels, overall weight, and quality of diet.
Although technically not a nut, but rather a dense and fatty foodstuff, walnuts are made of approximately 15% protein and 65% fat. Additionally, walnuts are rich in magnesium, and vitamins B and E.
While prior studies have touted the walnut’s ability to halt prostate cancer, reduce cholesterol and insulin sensitivity, and lower levels of IGF-1 in prostate and breast cancers, the current study led by David Katz, MD, Yale University Prevention Research Center, Griffin Hospital, New Haven, CT, more closely investigated these health claims.
The trial involved a total of 112 individuals 25-75 years old (all likely to develop diabetes) who were randomized to either receive counseling to gain a lower caloric diet or no counseling.
The two main groups were randomly separated into two more subgroups. The first ate 56g of walnuts daily, while the other avoided walnuts for six months. Following a 3-month break, the interventions were switched.
After taking factors such as age, regular exercise, and calorie/fat intake into consideration, the study authors found walnuts were, in fact, associated with improved quality of diet. More specifically, the study results indicated improved epithelial functioning and reduction in bad (LDL) cholesterol in the group who consumed walnuts.
It is important to note that since walnuts do have high caloric levels, the walnut-eating group did see an increase in total body fat, but a decrease in waist circumference.
Also, adding walnuts to their diets did not appear to have any significant effect on blood pressure, blood glucose, or good (HDL) cholesterol.
The authors concluded, “Our data suggest that inclusion of walnuts in the diet, with or without dietary counseling to adjust caloric intake, improved diet quality and may also improve endothelial function, and reduce total and LDL cholesterol in this sample o adults at risk for diabetes.”