***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background / objectives : Small dense low-density lipoprotein ( LDL ) particles and apolipoprotein ( apo ) CIII are risk factors for cardiovascular disease ( CVD ) that can be modulated by diet , but there is little information regarding the effects of dietary saturated fat on their plasma levels . We tested the effects of high vs low saturated fat intake in the context of a high beef protein diet on levels and composition of LDL subclasses and on apoCIII levels in plasma and LDL.Subjects/ methods : Following consumption of a baseline diet ( 50 % carbohydrate ( CHO ) , 13 % protein , 38 % total fat , 15 % saturated fat ) for 3 weeks , 14 healthy men were r and omly assigned to two reduced CHO high beef protein diets ( 31 % CHO , 31 % protein , 38 % fat ) that differed in saturated fat content ( 15 % vs 8 % ) for 3 weeks each in a crossover design . Results : The high saturated fat ( HSF ) diet result ed in higher mass concentrations of buoyant LDL I , medium density LDL II and dense LDL III , but not the very dense LDL IV ; and significant increases in plasma and LDL apoCIII concentration of 9.4 % and 33.5 % , respectively . The saturated fat-induced changes in LDL apoCIII were specifically correlated with changes in apoCIII content of LDL IV . Conclusions : Taken together with previous observations , these findings suggest that , at least in the context of a lower CHO high beef protein diet , HSF intake may increase CVD risk by metabolic processes that involve apoCIII The Minnesota Coronary Survey was a 4.5-year , open enrollment , single end-time , double-blind , r and omized clinical trial that was conducted In six Minnesota state mental hospitals and one nursing home . It Involved 4393 Institutionalized men and 4664 Institutionalized women . The trial compared the effects of a 39 % fat control diet ( 18 % saturated fat , 5 % polyunsaturated fat , 16 % monounsaturated fat , 446 mg dietary cholesterol per day ) with a 38 % fat treatment diet ( 9 % saturated fat , 15 % polyunsaturated fat , 14 % monounsaturated fat , 166 mg dietary cholesterol per day ) on serum cholesterol levels and the Incidence of myocardlal Infa rct ions , sudden deaths , and all-cause mortality . The mean duration of time on the diets was 384 days , with 1568 subjects consuming the diet for over 2 years . The mean serum cholesterol level In the pre-admission period was 207 mg/dl , falling to 175 mg/dl in the treatment group and 203 mg/dl In the control group . For the entire study population , no differences between the treatment and control groups were observed for cardiovascular events , cardiovascular deaths , or total mortality . A favorable trend for all these end-points occurred In some younger age groups BACKGROUND The Mediterranean and Dietary Approaches to Stop Hypertension ( DASH ) diets are characterized by higher intake of fruit , vegetables , whole grains , and unsaturated fatty acids . All of these foods and nutrients may affect cholesterol , inflammation , the development of atherosclerosis , and , therefore , risk of cardiac death . OBJECTIVE Our objective was to examine the association between the Mediterranean and DASH dietary patterns and risk of  sudden cardiac death ( SCD ) in women . DESIGN We used a prospect i ve cohort of 93,122 postmenopausal women enrolled in the Women 's Health Initiative study between 1993 and 1998 and followed for an average of 10.5 y. Women completed a food-frequency question naire ( FFQ ) twice during follow-up . We scored their diets according to how closely the reported diet resembled each dietary pattern . SCD was defined as death that occurred within 1 h of symptom onset . RESULTS A higher Mediterranean diet score was associated with lower risk of SCD ( HR : 0.64 ; 95 % CI : 0.43 , 0.94 ) when women in the highest quintile were compared with women in the lowest quintile after adjustment for age , total energy , race , income , smoking , and physical activity . After adjustment for potential mediators , the association was similar ( HR : 0.67 ; 95 % CI : 0.46 , 0.99 ) . A higher DASH diet score was not associated with risk of SCD . However , sodium intake , which is a crucial component of the DASH dietary pattern , was not well characterized by the FFQ . CONCLUSION The Mediterranean dietary pattern may be associated with lower risk of SCD in women . This trial was registered at clinical trials.gov as NCT00000611 BACKGROUND Some previous prospect i ve studies showed that dietary intake of omega3 polyunsaturated fatty acids was associated with lower risk of heart failure ( HF )  , but no study has examined the association between plasma fatty acids and HF . METHODS We included 3,592 white participants from the Minneapolis field center of the Atherosclerosis Risk in Communities ( ARIC ) Study , aged 45 to 64 at baseline ( 1987 - 1989 ) , initially free of coronary heart disease , stroke , and HF and who had cholesterol ester and phospholipid plasma fatty acids measured . Participants were followed through 2003 , and incident HF was defined by a hospital discharge or death including a HF International Classification of Diseases code . RESULTS During the 14.3-year follow-up , we identified 197 cases of HF ( 110 for men and 87 for women ) . After adjustment for age and other confounders , higher saturated fatty acids , especially myristic ( 14:0 ) acid , were associated positively with incident HF in both men and women . Higher arachidonic ( 20:3,omega6 ) and long-chain omega3 polyunsaturated fatty acids , especially docosahexaenoic ( 22:6,omega3 ) acid , were associated inversely with HF in women but not in men . Neither plasma alpha-linolenic nor eicosapentaenoic acid was associated with incident HF . CONCLUSIONS In both men and women , greater levels of saturated fatty acids may increase risk of HF . In women , arachidonic acid and long-chain omega3 polyunsaturated fatty acids may decrease risk of HF Abstract In a clinical trial of a diet low in saturated fat and cholesterol , and high in unsaturated fat of vegetable origin , carried out on 846 middle-aged and elderly men living in an institution , the subjects were allocated r and omly to the experimental diet or to a control diet , and were followed double-blind . The combined incidence of myocardial infa rct ion , sudden death , and cerebral infa rct ion was significantly lower in the experimental group than in the control group . The incidence of fatal atherosclerotic events was also lower in the experimental group than in the control group , but total mortality-rates were similar for the two groups Objective —To investigate the relationship between plasma levels of  small dense low-density lipoprotein-cholesterol ( sdLDL-C )  and risk for incident coronary heart disease ( CHD )  in a prospect i ve study among Atherosclerosis Risk in Communities ( ARIC ) study participants . Approach and Results —Plasma  sdLDL-C  was measured in 11 419 men and women of the biracial ARIC study using a newly developed homogeneous assay . A proportional hazards model was used to examine the relationship among sdLDL-C , vascular risk factors , and risk for CHD events  ( n=1158 ) for a period of ≈11 years . Plasma sdLDL-C levels were strongly correlated with an atherogenic lipid profile and were higher in patients with diabetes mellitus than non – diabetes mellitus ( 49.6 versus 42.3 mg/dL ; P<0.0001 ) . In a model that included established risk factors , sdLDL-C was associated with incident CHD with a hazard ratio of 1.51 ( 95 % confidence interval , 1.21–1.88 ) for the highest versus the lowest quartile , respectively . Even in individuals considered to be at low cardiovascular risk based on their LDL-C levels , sdLDL-C predicted risk for incident CHD ( hazard ratio , 1.61 ; 95 % confidence interval , 1.04–2.49 ) . Genome-wide association analyses identified genetic variants in 8 loci associated with sdLDL-C levels . These loci were in or close to genes previously associated with risk for CHD . We discovered 1 novel locus , PCSK7 , for which genetic variation was significantly associated with sdLDL-C and other lipid factors . Conclusions —sdLDL-C was associated with incident CHD in ARIC study participants . The novel association of genetic variants in PCSK7 with sdLDL-C and other lipid traits may provide new insights into the role of this gene in lipid metabolism The study deals with 412 men , aged 30 to 64 years , r and omized 1 to 2 years after a first myocardial infa rct ion . For the experimental group a diet low in saturated fats and cholesterol , and high in polyunsaturated fats was recommended . After 5 years , as reported previously , the incidence of fatal and nonfatal myocardial reinfa rct ion was found to be significantly reduced . “ Sudden death ” was uninfluenced . Major coronary heart disease ( CHD ) relapses , including fatal and nonfatal events ( MI ) , were significantly reduced ( P = 0.05).After 11 years , death from all causes had occurred in 101 of the original dieters and 108 controls . A significantly reduced myocardial infa rct ion mortality in the original diet group was found ( 32 versus 57 , P = 0.004 ) . The total number of coronary deaths ( fatal myocardial infa rct ion and sudden death ) was 79 in the diet group and 94 in the control group ( P = 0.097).The CHD mortality was correlated with age , serum cholesterol level , blood pressure , body weight , smoking habits , and a combination of these risk factors OBJECTIVE To describe the nutrient and food composition of the diets tested in the Optimal Macronutrient Intake Trial to Prevent Heart Disease ( OmniHeart ) . DESIGN Two center , r and omized , three-period crossover , controlled feeding trial that tested the effects of three healthful diet patterns on blood pressure , serum lipid levels , and estimated cardiovascular risk . SUBJECTS/ SETTING One hundred sixty-four participants with prehypertension and hypertension . During the 19 weeks of feeding , participants were required to consume only food prepared as part of the trial . INTERVENTION The OmniHeart trial studied three diet patterns that differed in macronutrient composition : a carbohydrate-rich diet similar to the Dietary Approaches to Stop Hypertension diet ( 58 % carbohydrate , 15 % protein , and 27 % fat ) , a higher protein diet that had 10 % more protein and 10 % less carbohydrate ( 48 % carbohydrate , 25 % protein , and 27 % fat ) , and a higher unsaturated fat diet that had 10 % more unsaturated fat and 10 % less carbohydrate ( 48 % carbohydrate , 15 % protein , and 37 % fat ) . Each diet contained 6 % saturated fat and 100 to 200 mg cholesterol . Sodium was 2,300 mg at the 2,100 kcal energy level and was indexed across energy levels . Calcium , magnesium , and potassium were consistent with recommendations for the Dietary Approaches to Stop Hypertension diet and also indexed to energy levels . Each diet pattern met the major nutrient recommendations set by the Dietary Guidelines for Americans 2005 . The 10 % protein increase in the higher protein diet emphasized plant protein ; however , meat and dairy food sources were also increased somewhat . Olive oil , canola oil , and olive oil spread were used liberally to achieve the unsaturated fat content of the higher unsaturated fat diet . The 10 % reduction in carbohydrate in the higher protein diet and the higher unsaturated fat diet was achieved by replacing some fruits with vegetables , reducing sweets , and using smaller portions of grain products . All three diets reduced blood pressure , total and low-density lipoprotein cholesterol levels , and estimated coronary heart disease risk . CONCLUSIONS The OmniHeart diet patterns offer substantial flexibility in macronutrient intake that should make it easier to eat a heart-healthy diet and reduce cardiovascular disease risk Low‐density lipoprotein ( LDL ) subclass pattern B is a common genetically influenced lipoprotein profile characterized by a predominance of small , dense LDL particles , and associated with increased levels of triglyceride‐rich lipoproteins , reductions in high‐density lipoprotein cholesterol ( HDL‐C ) , and increased risk of coronary artery disease compared to individuals with a predominance of larger LDL ( pattern A ) . We sought to determine whether LDL subclass patterns are associated with response of plasma lipoprotein levels to changes in dietary fat and carbohydrate content . In a r and omized cross‐over study , 105 men consumed , for six weeks each ,  high‐fat ( 
    Output:
    
The effects of reducing SFA on CHD risk vary with the nutrient of comparison , whether carbohydrates , monounsaturated or polyunsaturated fatty acids .
Substitution of SFA with polyunsaturated fatty acids was associated with a lower incidence of cardiovascular disease , while the effects of substitution with monounsaturated fatty acids or high-glycemic index carbohydrates are less clear