Significant heterogeneity was not observed by nut type or other factors .
Tree nut intake  lowers total cholesterol , LDL cholesterol , ApoB , and triglycerides .
The major determinant of cholesterol lowering appears to be nut dose rather than nut type .
BACKGROUND The effects of nuts on major cardiovascular disease ( CVD ) risk factors , including dose-responses and potential heterogeneity by nut type or phytosterol content , are not well established .
OBJECTIVES We examined the effects of tree nuts ( walnuts , pistachios , macadamia nuts , pecans , cashews , almonds , hazelnuts , and Brazil nuts ) on blood lipids [ total cholesterol , low-density lipoprotein ( LDL ) cholesterol , high-density lipoprotein , and triglycerides ] , lipoproteins [ apolipoprotein A1 , apolipoprotein B ( ApoB ) , and apolipoprotein B100 ] , blood pressure , and inflammation ( C-reactive protein ) in adults aged ≥18 y without prevalent CVD .
A Walnut Diet Improves Endothelial Function in Hypercholesterolemic Subjects: A Randomized Crossover Trial
Background —Epidemiological studies suggest that nut intake decreases coronary artery disease ( CAD ) risk . Nuts have a cholesterol-lowering effect that partly explains this benefit . Endothelial dysfunction is associated with CAD and its risk factors and is reversed by antioxidants and marine n-3 fatty acids . Walnuts are a rich source of both antioxidants and & agr;-linolenic acid , a plant n-3 fatty acid . Methods and Results —To test the hypothesis that walnut intake will reverse endothelial dysfunction , we r and omized in a crossover design 21 hypercholesterolemic men and women to a cholesterol-lowering Mediterranean diet and a diet of similar energy and fat content  in which walnuts replaced ≈32 % of the energy from monounsaturated fat . Participants followed each diet for 4 weeks . After each intervention , we obtained fasting blood and performed ultrasound measurements of brachial artery vasomotor function . Eighteen subjects completing the protocol had suitable ultrasound studies . Compared with the Mediterranean diet , the walnut diet improved endothelium-dependent vasodilation and reduced levels of vascular cell adhesion molecule-1 ( P < 0.05 for both ) . Endothelium-independent vasodilation and levels of intercellular adhesion molecule-1 , C-reactive protein , homocysteine , and oxidation biomarkers were similar after each diet . The walnut diet significantly reduced total cholesterol ( −4.4±7.4 % ) and LDL cholesterol ( −6.4±10.0 % ) ( P < 0.05 for both ) . Cholesterol reductions correlated with increases of both dietary & agr;-linolenic acid and LDL & ggr;-tocopherol content , and changes of endothelium-dependent vasodilation correlated with those of cholesterol-to-HDL ratios ( P < 0.05 for all ) . Conclusions —Substituting walnuts for monounsaturated fat in a Mediterranean diet improves endothelium-dependent vasodilation in hypercholesterolemic subjects . This finding might explain the cardioprotective effect of nut intake beyond cholesterol lowering
Significant heterogeneity was not observed by nut type or other factors .
Tree nut intake  lowers total cholesterol , LDL cholesterol , ApoB , and triglycerides .
The major determinant of cholesterol lowering appears to be nut dose rather than nut type .
BACKGROUND The effects of nuts on major cardiovascular disease ( CVD ) risk factors , including dose-responses and potential heterogeneity by nut type or phytosterol content , are not well established .
OBJECTIVES We examined the effects of tree nuts ( walnuts , pistachios , macadamia nuts , pecans , cashews , almonds , hazelnuts , and Brazil nuts ) on blood lipids [ total cholesterol , low-density lipoprotein ( LDL ) cholesterol , high-density lipoprotein , and triglycerides ] , lipoproteins [ apolipoprotein A1 , apolipoprotein B ( ApoB ) , and apolipoprotein B100 ] , blood pressure , and inflammation ( C-reactive protein ) in adults aged ≥18 y without prevalent CVD .