We assessed the effect of walnuts on lipid and glucose metabolism, adipokines, inflammation and endothelial function in healthy Caucasian men and postmenopausal women 鈮?#xA0;50 years old.
Forty subjects (mean 卤 SEM: age 60 卤 1 years, BMI 24.9 卤 0.6 kg/m2; 30 females) were included in a controlled, cross-over study and randomized to receive first a walnut-enriched (43 g/d) and then a Western-type (control) diet or vice-versa, with each lasting 8 weeks and separated by a 2-week wash-out. At the beginning and end of each diet phase, measurements of fasting values, a mixed meal test and an assessment of postprandial endothelial function (determination of microcirculation by peripheral artery tonometry) were conducted. Area under the curve (AUC), incremental AUC (iAUC) and treatment 脳 time interaction (shape of the curve) were evaluated for postprandial triglycerides, VLDL-triglycerides, chylomicron-triglycerides, glucose and insulin.
Compared with the control diet, the walnut diet significantly reduced non-HDL-cholesterol (walnut vs. control: 鈭?#xA0;10 卤 3 vs. 鈭?#xA0;3 卤 2 mg/dL; p = 0.025) and apolipoprotein-B (鈭?#xA0;5.0 卤 1.3 vs. 鈭?#xA0;0.2 卤 1.1 mg/dL; p = 0.009) after adjusting for age, gender, BMI and diet sequence. Total cholesterol showed a trend toward reduction (p = 0.073). Fasting VLDL-cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides and glucose, insulin, HOMA-IR, and HbA1c did not change significantly. Similarly, fasting adipokines, C-reactive protein, biomarkers of endothelial dysfunction, postprandial lipid and glucose metabolism and endothelial function were unaffected.
Daily consumption of 43 g of walnuts for 8 weeks significantly reduced non-HDL-cholesterol and apolipoprotein-B, which may explain in part the epidemiological observation that regular walnut consumption decreases CHD risk.