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 .
Effects of walnuts on serum lipid levels and blood pressure in normal men.
BACKGROUND In a recent six-year follow-up study , we found that frequent consumption of nuts was associated with a reduced risk of ischemic heart disease .  To explore possible explanations for this finding , we studied the effects of nut consumption on serum lipids and blood pressure . METHODS We r and omly placed 18 healthy men on two mixed natural diets  , each diet to be followed for four weeks . Both diets conformed to the National Cholesterol Education Program Step 1 diet and contained identical foods and macronutrients , except that 20 percent of the calories of one diet ( the walnut diet ) were derived from walnuts ( offset by lesser amounts of fatty foods , meat , and visible fat [ oils , margarine , and butter ] ) . RESULTS With the reference diet , the mean ( + /- SD ) serum values for total , low-density lipoprotein ( LDL ) , and high-density lipoprotein ( HDL ) cholesterol were , respectively , 182 + /- 23 , 112 + /- 16 , and 47 + /- 11 mg per deciliter ( 4.71 + /- 0.59 , 2.90 + /- 0.41 , and 1.22 + /- 0.28 mmol per liter ) . With the walnut diet , the mean total cholesterol level was 22.4 mg per deciliter ( 0.58 mmol per liter ) lower than the mean level with the reference diet ( 95 percent confidence interval , 28 to 17 mg per deciliter [ 0.72 to 0.44 mmol per liter ] ) ; the LDL and HDL cholesterol levels were , respectively , 18.2 mg per deciliter ( 0.47 mmol per liter ) ( P < 0.001 ) and 2.3 mg per deciliter ( 0.06 mmol per liter ) ( P = 0.01 ) lower . These lower values represented reductions of 12.4 , 16.3 , and 4.9 percent in the levels of total , LDL , and HDL cholesterol , respectively . The ratio of LDL cholesterol to HDL cholesterol was also lowered ( P < 0.001 ) by the walnut diet .  Mean blood-pressure values did not change during either dietary period . CONCLUSIONS Incorporating moderate quantities of walnuts into the recommended cholesterol-lowering diet while maintaining the intake of total dietary fat and calories decreases serum levels of total cholesterol and favorably modifies the lipoprotein profile in normal men . The long-term effects of walnut consumption and the extension of this finding to other population groups deserve further study
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 .