title: Dietary alpha-linolenic acid inhibits proinflammatory cytokine production by peripheral blood mononuclear cells in hypercholesterolemic subjects. A macadamia nut-rich diet reduces total and LDL-cholesterol in mildly hypercholesterolemic men and women. Substituting Walnuts for Monounsaturated Fat Improves the Serum Lipid Profile of Hypercholesterolemic Men and Women A Walnut Diet Improves Endothelial Function in Hypercholesterolemic Subjects: A Randomized Crossover Trial The effect of walnut intake on factors related to prostate and vascular health in older men The chronic intake of a Mediterranean diet enriched in virgin olive oil, decreases nuclear transcription factor kappaB activation in peripheral blood mononuclear cells from healthy men. Effect of a traditional Mediterranean diet on lipoprotein oxidation: a randomized controlled trial. Serum lipid profiles in Japanese women and men during consumption of walnuts A diet rich in walnuts favourably influences plasma fatty acid profile in moderately hyperlipidaemic subjects Including walnuts in a low-fat/modified-fat diet improves HDL cholesterol-to-total cholesterol ratios in patients with type 2 diabetes. Does regular walnut consumption lead to weight gain? Effects of Plant-Based Diets High in Raw or Roasted Almonds, or Roasted Almond Butter on Serum Lipoproteins in Humans Effects of walnut consumption as part of a low-fat, low-cholesterol diet on serum cardiovascular risk factors. Effects of walnuts on serum lipid levels and blood pressure in normal men. Effect of Walnut-Enriched Restructured Meat in the Antioxidant Status of Overweight/Obese Senior Subjects with at Least One Extra CHD-Risk Factor
abstract: BACKGROUND Atherosclerosis is a chronic inflammatory disease . We previously reported that a diet high in alpha-linolenic acid ( ALA ) reduces lipid and inflammatory cardiovascular disease risk factors in hypercholesterolemic subjects . OBJECTIVE The objective was to evaluate the effects of a diet high in ALA on serum proinflammatory cytokine concentrations and cytokine production by cultured peripheral blood mononuclear cells ( P BMC s ) from subjects fed the experimental diets . DESIGN A r and omized , controlled , 3-diet , 3-period crossover study design was used . Hypercholesterolemic subjects ( n = 23 ) were assigned to 3 experimental diets : a diet high in ALA ( ALA diet ; 6.5 % of energy ) , a diet high in linoleic acid ( LA diet ; 12.6 % of energy ) , and an average American diet ( AAD ) for 6 wk . Serum interleukin (IL)-6 , IL-1beta , and tumor necrosis factor-alpha ( TNF-alpha ) concentrations and the production of IL-6 , IL-1beta , and TNF-alpha by P BMC s were measured . RESULTS IL-6 , IL-1beta , and TNF-alpha production by P BMC s and serum TNF-alpha concentrations were lower ( P < 0.05 and P < 0.08 , respectively ) with the ALA diet than with the LA diet or AAD .  P BMC production of TNF-alpha was inversely correlated with ALA ( r = -0.402 , P = 0.07 ) and with eicosapentaenoic acid ( r = -0.476 , P = 0.03 ) concentrations in P BMC lipids with the ALA diet . Changes in serum ALA were inversely correlated with changes in TNF-alpha produced by P BMC s ( r = -0.423 , P < 0.05 ) . CONCLUSIONS Increased intakes of dietary ALA elicit antiinflammatory effects by inhibiting IL-6 , IL-1beta , and TNF-alpha production in cultured P BMC s. Changes in P BMC ALA and eicosapentaenoic acid ( derived from dietary ALA ) are associated with beneficial changes in TNF-alpha release . Thus , the cardioprotective effects of ALA are mediated in part by a reduction in the production of inflammatory cytokines Epidemiologic studies and clinical trials have demonstrated that the unique fatty acid profile of nuts beneficially affects serum lipids/lipoproteins , reducing cardiovascular disease ( CVD ) risk .  Nuts are low in SFA and high in PUFA and monounsaturated fatty acids ( MUFA ) . Macadamia nuts are a rich source of MUFA . A r and omized , crossover , controlled feeding study ( 5-wk diet periods ) compared a Macadamia nut-rich diet [ 42.5 g ( 1.5 ounces)/8.79 MJ ( 2100 kcal ) ] [ MAC ; 33 % total fat ( 7 % SFA , 18 % MUFA , 5 % PUFA ) ] vs. an average American diet [ AAD ; 33 % total fat ( 13 % SFA , 11 % MUFA , 5 % PUFA ) ] on the lipid/lipoprotein profile of mildly hypercholesterolemic ( n = 25 ; 15 female , 10 male ) subjects .  Serum concentrations of total cholesterol ( TC ) and LDL cholesterol ( LDL-C ) following the MAC ( 4.94 + /- 0.17 mmol/L , 3.14 + /- 0.14 mmol/L ) were lower than the AAD ( 5.45 + /- 0.17 mmol/L , 3.44 + /- 0.14 mmol/L ; P < 0.05 ) . The serum non-HDL cholesterol ( HDL-C ) concentration and the ratios of TC : HDL-C and LDL-C : HDL-C were reduced following consumption of the MAC diet ( 3.83 + /- 0.17 , 4.60 + /- 0.24 , and 2.91 + /- 0.17 , respectively ) compared with the AAD ( 4.26 + /- 0.17 , 4.89 + /- 0.24 , and 3.09 + /- 0.18 , respectively ; P < 0.05 ) . There was no change in serum triglyceride concentration . Thus , macadamia nuts can be included in a heart-healthy dietary pattern that reduces lipid/lipoprotein CVD risk factors . Nuts as an isocaloric substitute for high SFA foods increase the proportion of unsaturated fatty acids and decrease SFA , thereby lowering CVD risk Lifestyle modification is the cornerstone of population -based strategies for prevention of coronary heart disease and is the first line of therapy in patients with hypercholesterolemia . Diets low in saturated fatty acids and cholesterol have long been recommended to decrease low-density lipoprotein ( LDL ) cholesterol levels and reduce cardiovascular risk ( 1 ) . Ample evidence suggests that polyunsaturated fatty acids and monounsaturated fatty acids have a similar cholesterol-lowering effect when substituted for saturated fatty acids ( 2 - 4 ) . However , most studies of fatty acids and blood lipids have been done with fats and oils , rarely with whole fatty foods . Because people usually buy and consume whole food products , it is desirable to know the effects of specific foods on risk factors for coronary heart disease . Recent reports suggest that the regular consumption of nuts might reduce cardiovascular risk ( 5 ) . Walnuts are particularly rich in polyunsaturated fatty acids ( 6 ) , and epidemiologic evidence suggests that frequent walnut consumption protects against coronary heart disease ( 7 ) . In a controlled feeding trial by Sabat and colleagues ( 8) , a diet in which walnuts represented 55 % of the energy from fat reduced blood cholesterol levels in normal young men when compared with a st and ard low-fat diet . However , the results can not easily be extrapolated to the population at risk for coronary heart disease because women , older age groups , and hypercholesterolemic persons were not studied ( 8) . In addition , because meals were served at a metabolic kitchen , the study did not address the question of whether free-living persons would incorporate substantial quantities of walnuts into their diets . Because oxidized LDL plays a key role in atherogenesis ( 9 ) and oxidative damage involves peroxidation of polyunsaturated fatty acids in LDL lipids ( 10 ) , there is concern that walnut intake may promote LDL oxidation . Therefore , we design ed a dietary intervention study in free-living adult men and women with polygenic hypercholesterolemia to compare the effects of a walnut-rich diet with those of a cholesterol-lowering Mediterranean diet on serum lipid levels , lipoprotein levels , and LDL resistance to oxidation . Methods Patients Adult men and women with polygenic hypercholesterolemia attending the Lipid Clinic of the Hospital Clnic of Barcelona were eligible if they had serum LDL cholesterol concentrations greater than 3.36 mmol/L ( 130 mg/dL ) and triglyceride concentrations less than 2.82 mmol/L ( 250 mg/dL ) ; no evidence of alcohol , tobacco , or drug abuse ; absence of diabetes mellitus and liver , kidney , thyroid , or other endocrine diseases , as assessed by medical history , a complete physical examination , and laboratory tests ; no intake in the previous 8 weeks of medications known to affect lipid metabolism , including hypolipidemic agents and estrogen compounds in women ; infrequent consumption of nuts and no known history of allergy to them ; and no use of multivitamin or vitamin E supplements  . Because the target population had common ( polygenic ) hypercholesterolemia , we excluded persons whose elevated blood cholesterol levels had a strong genetic basis ( such as heterozygous familial hypercholesterolemia or familial combined hyperlipidemia ) , as established by st and ard criteria . On admission to the Lipid Clinic , all patients were advised to follow a  Mediterranean-type hypolipidemic diet ( 11 ) . For a crossover design , statistical power calculations indicated that to detect mean differences of 0.39 mmol/L ( 15 mg/dL ) , 34 patients would need to complete the two treatment periods ( statistic , 0.05 ; power>0.8 ) . From a computerized register of clinical records , 75 hypercholesterolemic patients ( 35 women and 40 men ) who initially met the eligibility criteria were selected for screening and were asked to participate in the study . They were offered free walnuts but no monetary compensation . Study Design A crossover design was used . Patients were r and omly assigned to the two diet sequences by using a computer-generated r and om-number table , with stratification by sex . Because patients followed each diet for 6 weeks and lipoprotein changes due to dietary intervention stabilize in less than 4 weeks ( 12 ) , we did not incorporate a washout period between diets . In their crossover feeding study with walnuts , Sabat and colleagues ( 8) did not observe a carryover effect . In the week before the trial began , patients received expert dietary counseling individually and in a group class . Twice during the pretrial week and on weeks 5 and 6 of each one of the two dietary periods , patients came to the clinic for a medical visit , an interview with the dietitian , anthropometric measurements , and blood extraction . The main outcomes of the study were changes in serum levels of total and LDL cholesterol from the control diet period to the walnut diet period . Secondary outcomes were changes in other lipid variables and oxidizability of LDL particles . The study protocol was approved by the institutional review board of the Hospital Clnic of Barcelona , and all patients gave informed consent . Diets The experimental diets were individually prescribed and were based on estimated energy requirements . Because participants ate on their own , detailed dietary information was provided to them and , if appropriate , to their partners .  Diets were calculated in increments of 200 kcal to cover the range from 1600 to 2200 kcal . The control diet was Mediterranean and was composed of natural foodstuffs . Red meat and eggs were limited , vegetable products and fish were emphasized , olive oil was indicated for culinary use , and no nuts were allowed . The walnut diet was similar to the control diet , but walnuts partially replaced olive oil and other fatty foods . Prepackaged daily allowances of raw , shelled walnuts were provided daily in amounts varying from 41 g to 56 g ( the equivalent of 8 to 11 walnuts ) , according to the participants ' total energy intake . Walnuts were consumed as snacks or with meals in desserts or salads . In the walnut diet , walnuts contributed approximately 18 % of the total energy and 35 % of the total fat . To improve compliance , each family unit was given 1000-g packs of walnuts at the beginning of the walnut diet period .  Adherence to the study diets was carefully monitored . Unannounced 24-hour diet recalls were performed weekly by telephone during the two dietary periods , for a total of 12 recalls per patient . This method allows reliable estimations of food intake ( 13 ) . The nutrient composition of the diets was calculated with Food Processor Plus software , version 5.0 ( ESHA Research , Salem , Oregon ) , which was adapted to nutrient data bases of specific Mediterranean foods when appropriate . We defined noncompliance as at least 20 % deviation from dietary instructions regarding walnut or nutrient intake . Compliance during the walnut diet was also assessed at each clinic visit by a count of the empty walnut packages . The fatty acid content of LDL lipids was analyzed as a biological measure of adherence to the prescribed diets . Laboratory Measurements Blood sample s were obtained after an overnight fast , and serum and EDTA plasma were collected and processed immediately . Serum lipid and apolipoprotein levels were determined as described elsewhere ( 11 ) . In brief , serum cholesterol and triglyceride levels were measured by using enzymatic reagents ( Trinder , Bayer Diagnostics , Tarrytown , New York ) adapted to a Cobas Mira automated analyzer ( Hoffmann-LaRoche , Basel , Switzerl and ) . High-density lipoprotein ( HDL ) cholesterol was quantified after precipitation with phosphotungstic acid and magnesium chloride . Levels of apolipoprotein A-I and apolipoprotein B were determined by an immunoturbidimetric method ( Unimate 3 , Roche Diagnostic Systems , Basel , Switzerl and ) . Measurements of the cholesterol content of very-low-density lipoprotein particles and LDL particles were based on preparative ultracentrifugation ( 11 ) . Lipoprotein(a ) levels were measured by using an immunoturbidimetric method ( Lipoprotein[a ] SPQ II Test Kit , DiaSorin , Stillwater , Minnesota ) . To obtain the LDL fraction for fatty acid and oxidizability studies , lipoproteins were fractionated by sequential centrifugation adjusting with NaBr to separate very-low-density lipoprotein particles ( d=1.006 g/mL ) and to obtain LDL particles ( d=1.063 g/mL ) , as described elsewhere ( 14 ) . Low-density lipoprotein fatty acids were measured by capillary gas chromatography in the cholesteryl ester , phospholipid , and triglyceride lipid fractions ( 14 ) . Low-density lipoprotein susceptibility to oxidation was determined by measuring the -tocopherol content of LDL particles and conjugated diene kinetics after incubation of 50 g of LDL protein with 5 mol of copper sulfate at 37 C ( 15 , 16 ) . Statistical Analysis The two measurements obtained at baseline and at the end of each dietary period were averaged . Means and SDs are presented for each measurement . With methods described by Fleiss ( 17 ) , two-tailed t-tests were used to compare changes in outcome variables in response to dietary treatment and diet period and carryover effects for the two-period crossover design . Differences between the walnut and control diets were also tested by analysis of covariance using general linear models ; baseline values or sex were used as covariates . Analyses were performed by using SAS software ( SAS , Inc. , Cary , North Carolina ) ( 18 ) . Role of the Funding Sources The California Walnut Commission provided funding and walnuts . Research grants were also obtained from national and local nonprofit agencies . The funding sources were not involved in the design of the study and had no role in the collection , analysis , or interpretation of the data or in the decision to su bmi t the manuscript for publication . None of the authors has any financial interest in the nut food industry . Results Patient Characteristics Of the 75 eligible patients , 20 left the study before r and omization for 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 Background Tocopherols may protect against prostate cancer and cardiovascular disease ( CVD ) . Methods We assessed the effect of walnuts , which are rich in tocopherols , on markers of prostate and vascular health in men at risk for prostate cancer . We conducted an 8-week walnut supplement study to examine effects of walnuts on serum tocopherols and prostate specific antigen ( PSA ) . Subjects ( n = 21 ) consumed ( in r and om order ) their usual diet + /- a walnut supplement ( 75 g/d ) that was isocalorically incorporated in their habitual diets . Prior to the supplement study , 5 fasted subjects participated in an acute timecourse experiment and had  blood taken at baseline and 1 , 2 , 4 , and 8 h after consuming walnuts ( 75 g ) . Results During the timecourse experiment , triglycerides peaked at 4 h , and gamma-tocopherol ( γ-T ) increased from 4 to 8 h. Triglyceride – normalized γ-T was two-fold higher ( P = 0.01 ) after 8 versus 4 h. In the supplement study , change from baseline was + 0.83 ± 0.52 μmol/L for γ-T , -2.65 ± 1.30 μmol/L for alpha-tocopherol ( α-T ) and -3.49 ± 1.99 for the tocopherol ratio ( α-T : γ-T ) . A linear mixed model showed that , although PSA did not change , the ratio of free PSA : total PSA increased and approached significance ( P = 0.07 ) . The α-T : γ-T ratio decreased significantly ( P = 0.01 ) , partly reflecting an increase in serum γ-T , which approached significance ( P = 0.08 ) . Conclusion The significant decrease in the α-T : γ-T ratio with an increase in serum γ-T and a trend towards an increase in the ratio of free PSA : total PSA following the 8-week supplement study suggest that walnuts may improve biomarkers of prostate and vascular status OBJECTIVE Nuclear transcription factor kappaB ( NF-kappaB ) plays a key role in the inflammatory response and can be modulate by dietary fat . We have examined the effect of three diets , with different fat composition , on the activation of NF-kappaB on peripheral blood mononuclear cells ( P BMC s ) . METHODS Sixteen healthy men followed three 4-week diets , in a r and omised crossover design : a Western diet , rich in saturated fat ( SFA ) [ 22 % SFA , 12 % monounsaturated fat ( MUFA ) and 0 , 4 alpha-linolenic acid ] ; a Mediterranean diet [ < 10 % SFA , 24 % MUFA and 0.4 % alpha-linolenic acid ] , and a low fat diet enriched in alpha-linolenic acid [ < 10 % SFA , 12 % MUFA and 2 % alpha-linolenic acid ] . NF-kappaB ( electrophoretic mobility shift assay ) in mononuclear cells and plasma concentrations ( ELISA ) of soluble vascular cellular adhesion molecule 1 ( VCAM-1 ) were examined after either diets . RESULTS Western diet increased 2.7-fold NF-kappaB compared with the Mediterranean diet ( p=0.038 ) and 1.79-fold with the alpha-linolenic acid diet ( p=0.07 ) . No differences were found between the last two . Furthermore , an increase on plasma VCAM-1 was observed with the Western diet ( p<0.05 ) . CONCLUSIONS The Mediterranean diet diminished NF-kappaB activation in mononuclear cells , compared with Western diet , supporting its cardioprotective properties . The effect of the n-3 enriched diet was intermediate BACKGROUND Despite the richness in antioxidants of the Mediterranean diet , to our knowledge , no r and omized controlled trials have assessed its effect on in vivo lipoprotein oxidation . METHODS A total of 372 subjects at high cardiovascular risk ( 210 women and 162 men ; age range , 55 - 80 years ) , who were recruited into a large , multicenter , r and omized , controlled , parallel-group clinical trial ( the Prevención con Dieta Mediterránea [ PREDIMED ] Study ) directed at testing the efficacy of the traditional Mediterranean diet ( TMD ) on the primary prevention of coronary heart disease , were assigned to a low-fat diet ( n = 121 ) or one of 2 TMDs ( TMD + virgin olive oil or TMD + nuts ) . The TMD participants received nutritional education and either free virgin olive oil for all the family ( 1 L/wk ) or free nuts ( 30 g/d ) . Diets were ad libitum . Changes in oxidative stress markers were evaluated at 3 months . RESULTS After the 3-month interventions , mean ( 95 % confidence intervals ) oxidized low-density lipoprotein ( LDL ) levels decreased in the TMD + virgin olive oil ( -10.6 U/L [ -14.2 to -6.1 ] ) and TMD + nuts ( -7.3 U/L [ -11.2 to -3.3 ] ) groups , without changes in the low-fat diet group ( -2.9 U/L [ -7.3 to 1.5 ] ) . Change in oxidized LDL levels in the TMD + virgin olive oil group reached significance vs that of the low-fat group ( P = .02 ) . Malondialdehyde changes in mononuclear cells paralleled those of oxidized LDL . No changes in serum glutathione peroxidase activity were observed . CONCLUSIONS Individuals at high cardiovascular risk who improved their diet toward a TMD pattern showed significant reductions in cellular lipid levels and LDL oxidation . Results provide further evidence to recommend the TMD as a useful tool against risk factors for CHD . Trial Registration is rct n.org Identifier : IS RCT N35739639 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 ) Objective : To compare two low fat diets one rich in walnuts on parameters of lipid metabolism in a group of hyperlipidaemic subjects . Design : A r and omised cross over study . Setting : Department of Human Nutrition , University of Otago , Dunedin , New Zeal and Subjects : Twenty one men with mean ( s.d ) levels of total and LDL cholesterol of 6.58 ( 0.60 ) and 4.63 ( 0.58 ) respectively . Interventions : For two periods of four weeks subjects were asked to consume two low fat diets ( fat 30 % total energy ) , one containing , on average , 78 g/d walnuts . Walnuts obtained through Lincoln University and the Walnut Growers Group ( South Canterbury ) . Results : Participants reported a higher total fat intake on the walnut diet ( 38 % compared with 30 % on the low fat diet P<0.01 ) The most consistent change in fatty acid profile of triacylglycerol , phospholipid and cholesterol ester on the walnut diet was a significant ( P<0.01 ) increase in linoleic acid . Triacylglycerol linolenate also increased significantly ( P<0.01 ) . Total and LDL cholesterol were lower on both experimental diets than at baseline , 0.25 mmol/l and 0.36 mmol/l respectively on the walnut diet and 0.13 mmol/l and 0.20 mmol/l respectively on the low fat diet . High density lipoprotein cholesterol was higher on both the walnut and low fat diets when compared to baseline ( 0.15 mmol/l and 0.12 mmol/l , respectively ) . When comparing the walnut and low fat diets only apo B was significantly lower ( P<0.05 ) on the walnut diet . Conclusions : Despite an unintended increase in the total fat intake on the walnut diet , fatty acid profile of the major lipid fractions showed changes which might be expected to reduce risk of cardiovascular disease . The reduction of apolipoprotein B suggests a reduction in lipoprotein mediated risk , the relatively low myristic acid content of both diets perhaps explaining the absence of more extensive differences in lipoprotein levels on the two diets . Sponsorship : Nutrition Department University of Otago , New Zeal and OBJECTIVE The aim of this study was to examine the effect of a moderate-fat diet inclusive of walnuts on blood lipid profiles in patients with type 2 diabetes . RESEARCH DESIGN AND METHODS This was a parallel r and omized controlled trial comparing three dietary advice groups each with 30 % energy as fat : low fat , modified low fat , and modified low fat inclusive of 30 g of walnuts per day .  Fifty-eight men and women , mean age 59.3 + /- 8.1 years , started the trial . Dietary advice was given at baseline with monthly follow-up and fortnightly phone calls for support .  Body weight , percent body fat , blood lipids , HbA1c , total antioxidant capacity , and erythrocyte fatty acid levels were measured at 0 , 3 , and 6 months . Data were assessed by repeated- measures ANOVA with an intention-to-treat model . RESULTS The walnut group achieved a significantly greater increase in HDL cholesterol-to-total cholesterol ratio ( P=0.049 ) and HDL ( P=0.046 ) than the two other treatment groups . A 10 % reduction in LDL cholesterol was also achieved in the walnut group , reflecting a significant effect by group ( P=0.032 ) and time ( P=0.036 ) . There were no significant differences between groups for changes in body weight , percent body fat , total antioxidant capacity , or HbA1c levels . The higher dietary polyunsaturated fat-to-saturated fat ratio and intakes of omega-3 fatty acids in the walnut group were confirmed by erythrocyte biomarkers of dietary intake . CONCLUSIONS Structured " whole of diet " advice that included 30 g of walnuts/day delivering substantial amounts of polyunsaturated fatty acid improved the lipid profile of patients with type 2 diabetes Studies consistently show the beneficial effects of eating nuts , but as high-energy foods , their regular consumption may lead to weight gain . We tested if daily consumption of walnuts ( approximately 12 % energy intake ) for 6 months would modify body weight and body composition in free-living subjects . Ninety participants in a 12-month r and omized cross-over trial were instructed to eat an allotted amount of walnuts ( 28 - 56 g ) during the walnut-supplemented diet and not to eat them during the control diet , with no further instruction . Subjects were unaware that body weight was the main outcome . Dietary compliance was about 95 % and mean daily walnut consumption was 35 g during the walnut-supplemented diet . The walnut-supplemented diet result ed in greater daily energy intake ( 557 kJ ( 133 kcal ) ) , which should theoretically have led to a weight gain of 3.1 kg over the 6-month period . For all participants , walnut supplementation increased weight ( 0.4 ( se 0.1 ) kg ) , BMI ( 0.2 ( se 0.1 ) kg/m(2 ) ) , fat mass ( 0.2 ( se 0.1 ) kg ) and lean mass ( 0.2 ( se 0.1 ) kg ) . But , after adjusting for energy differences between the control and walnut-supplemented diets , no significant differences were observed in body weight or body composition parameters , except for BMI ( 0.1 ( se 0.1 ) kg/m(2 ) ) . The weight gain from incorporating walnuts into the diet ( control-->walnut sequence ) was less than the weight loss from withdrawing walnuts from the diet ( walnut-->control sequence ) . Our findings show that regular walnut intake result ed in weight gain much lower than expected and which became non-significant after controlling for differences in energy intake Objective : To compare the lipid-altering effect of roasted salted almonds and roasted almond butter with that of raw almonds , as part of a plant-based diet . Methods : Thirty-eight free-living , hypercholesterolemic men ( n = 12 ) and women ( n = 26 ) with a mean total serum cholesterol ( TC ) of 245 + 29 mg/dL ( mean + SD ) followed a heart-healthy diet  including 100 g of one of three forms of almonds : roasted salted almonds , roasted almond butter or raw almonds for four weeks . Measurements of serum TC , triglycerides ( TG ) , selected lipoproteins and blood pressure were taken at baseline and after four weeks . Results : All three forms of almonds in the context of a heart-healthy diet significantly lowered low-density lipoprotein-cholesterol ( LDL ) from baseline to the completion of the study . Both raw and roasted almonds significantly lowered TC , whereas the decrease by almond butter ( in a smaller cohort ) did not reach statistical significance . High-density lipoprotein-cholesterol ( HDL ) did not significantly change with raw or roasted almonds but slightly increased with almond butter . At the end of the study , blood pressure did not change significantly from baseline values for any of the groups . Conclusion : These results suggest that unblanched almonds — whether raw , dry roasted , or in roasted butter form — can play an effective role in cholesterol-lowering , plant-based diets Serum components , such as lipoproteins , coagulation factors ( factor VII , tissue plasminogen activator ( tPA ) , plasminogen activator inhibitor-1 ( PAI-1 ) , fibrinogen ) , and homocysteine have been associated with cardiovascular disease . Dietary intervention with a low-fat , low-cholesterol diet has favorably influenced cardiovascular disease and certain food , specifically the consumption of nuts , has been associated with reduced cardiovascular risks . The effects of walnuts , as part of a low-fat , low-cholesterol diet , on serum cardiovascular risk factors were determined . Sixty-seven ( 67 ) out patients with borderline high total cholesterol following a low-fat , low-cholesterol diet for six weeks before being r and omly assigned to continue the diet or have 64 grams/day of walnuts in conjunction with the diet . After six weeks , the patients ' diets were switched . Therefore , all patients consumed 64 grams/day of walnuts for six weeks during part of the trial as part of a low-fat , low cholesterol diet .  Serum lipids demonstrated a significant reduction in triacyglycerols and favorable trend with decreases in total cholesterol , low-density lipoprotein ( LDL ) cholesterol , and a slight increase in high-density lipoprotein ( HDL ) cholesterol . No statistical effects on homocysteine or the coagulation factors were observed . However , there was a slight favorable trend for tPA and PAI-1 . This study demonstrated that walnuts , when consumed as part of a low fat , low-cholesterol diet , have a beneficial effect on serum cardiovascular risk factors . However , these changes may not explain all of the beneficial effects that walnut consumption has on cardiovascular disease 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 Background : A number of recent studies indicate that antioxidants reduce the oxidative stress associated with the development of coronary heart diseases ( CHD ) . Objective : ( i ) To investigate whether the erythrocyte catalase ( CAT ) , superoxide dismutase ( SOD ) , total glutathione , reduced glutathione ( GSH ) , oxidized glutathione ( GSSG ) , and lipid peroxidation ( LPO ) , and serum uric acid and paraoxonase-1 ( PON1 ) are modified at increased CHD-risk individuals consuming walnut-enriched meat ( WM ) , ( ii ) to evaluate whether these changes were influenced by basal serum cholesterol , body mass index or smoking habit . Design : The study was a non blinded , cross-over , placebo-controlled trial in which 22 volunteers ( 60 % overweight and 40 % obese ) with increased CHD-risk were r and omly assigned to receive WM or control meat ( CM ) during two different periods of 5 weeks . Results : A significant interaction time*treatment ( p < 0.05 ) was observed in all enzymes and substrates tested except HDL-C , uric acid and LPO . The treatment significantly increased CAT activity , total glutathione and GSSG ( p < 0.05 ) . Significant gender*time*treatment interaction ( p = 0.043 ) for total glutathione was found increasing at the end of the WM period in male but not changing in female . Total glutathione and GSH/GSSG ratio ( p < 0.05 ) were lower in smokers . Hypercholesterolemics presented higher uric acid ( p < 0.05 ) but no enzyme activities or substrate concentrations were different from those of normocholesterolemics . Conclusions : The WM tested appears to be a functional food as it improved the antioxidant status of increased CHD-risk volunteers . Despite its high energy content , it also appears adequate for overweight and obese people because did not exert negative effect upon body weight
target: Overall , high-walnut-enriched diets significantly decreased total and LDL cholesterol for the duration of the short-term trials .
background: 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 .