Overall , high-walnut-enriched diets significantly decreased total and LDL cholesterol for the duration of the short-term trials .
BACKGROUND Consumption of nuts has been associated with a decreased risk of  cardiovascular disease events  and death .
Walnuts in particular have a unique profile : they are rich in polyunsaturated fatty acids , which may improve blood lipids and other cardiovascular disease risk factors .
OBJECTIVES We aim ed to conduct a literature review and a meta- analysis to combine the results from several trials and to estimate the effect of walnuts on blood lipids .
Serum lipid profiles in Japanese women and men during consumption of walnuts
Objective : To determine the serum cholesterol , apolipoproteins and LDL oxidizability in young Japanese women and men during walnut consumption and to evaluate its active principle . Design : Experimental study with a r and omized design .Subjects : Twenty healthy women and 20 healthy men . Interventions : Subjects were r and omly assigned to consume each of two mixed natural diets for 4 weeks in a cross-over design . Reference and walnut diets were design ed and the walnut diet had 12.5 % of the energy derived from walnuts ( 44–58 g/day ) . Results : The total cholesterol and serum apolipoprotein B concentrations , and the ratio of LDL cholesterol to HDL cholesterol was significantly lowered in women and men when fed on the walnut diet , than when on the reference diet ( P≤0.05 ) . The LDL cholesterol concentration was significantly lowered in women on the walnut diet ( 0.22 mmol/l , P=0.0008 ) , whereas this decrease was not significant in men ( 0.18 mmol/l , P=0.078 ) . The most prominent change in the fatty acid composition of the cholesteryl esters from serum after the walnut diet was an elevation of α-linolenic acid in women ( 76 % , P<0.001 ) and men ( 107 % , P<0.001 ) . This elevation was negatively correlated to the change in LDL cholesterol in women ( r=0.496 , P=0.019 ) and men ( r=0.326 , P=0.138 ) . The LDL oxidizability in women was not influenced by the diets ( P=0.19 ) . Conclusions : α-Linolenic acid in the walnut diet appears to be responsible for the lowering of LDL cholesterol in women . Sponsorship : Kyushu University ( Fukuoka , Japan ) and the California Walnut Commission ( California , USA )
Overall , high-walnut-enriched diets significantly decreased total and LDL cholesterol for the duration of the short-term trials .
BACKGROUND Consumption of nuts has been associated with a decreased risk of  cardiovascular disease events  and death .
Walnuts in particular have a unique profile : they are rich in polyunsaturated fatty acids , which may improve blood lipids and other cardiovascular disease risk factors .
OBJECTIVES We aim ed to conduct a literature review and a meta- analysis to combine the results from several trials and to estimate the effect of walnuts on blood lipids .