Abstract
Even though many studies have shown that walnuts have beneficial effects on lipid profiles in various populations, there have been limited data on the effects of walnuts in Korean populations. We examined not only the effects of walnut intake on lipid profiles among Korean adults but also focused on the sub-classification by waist circumference (WC). 89 subjects out of 119 completed trial with daily consumption of 45g of walnuts for 16 weeks. Blood lipid profiles including triglycerides (TG), non-HDL cholesterol (non-HDL-C), LDL cholesterol (LDL-C), total cholesterol (TC), and HDL cholesterol (HDL-C), apolipoprotein B, anthropometric measurements (WC, weight, body mass index (BMI) and blood pressure) and glucose metabolism parameters including fasting blood sugar and insulin levels were assessed. Whose WC was greater than 85 cm for female and 90 cm for male were classified as higher WC group (n = 48) and others were classified as normal WC group (n = 41). Blood levels of non-HDL-C, LDL-C, TC and apolipoprotein B were improved after daily consumption of 45g of walnuts (P = 0.003, P = 0.011, P = 0.002, and P = 0.012, respectively) compared to baseline levels. Systolic blood pressure, TG, non-HDL-C, LDL-C and TC were significantly decreased in the higher WC groups (P = 0.048, P = 0.002, P = 0.002 and P = 0.001, respectively) compared to normal WC group. The results suggest that consuming 45 g of walnuts daily for 16 weeks had beneficial effects on lipid profiles in general, and These results were even much stronger among the subjects with abdominal obesity as waist circumference compared to those with non-abdominal obesity. This trial was registered at ClinicalTrials.gov as NCT03267901.