human
***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 Previous observational studies of self-reported dairy product consumption and stroke risk have reported mixed findings . Few studies have used circulating biomarkers that provide objective measures of dairy fat intake . OBJECTIVES We tested the hypothesis that the circulating biomarkers of dairy fat , pentadecanoic acid ( 15:0 ) , heptadecanoic acid ( 17:0 ) , and trans palmitoleate ( trans 16:1n-7 ) , were associated with lower incidence of stroke , especially ischemic stroke . Secondarily , we evaluated 14:0 , which is obtained from dairy products and beef , and also endogenously synthesized . DESIGN In participants from 2 large US cohorts ( the Health Professionals Follow-Up Study : 51,529 men ; the Nurses ' Health Study : 121,700 women ) with stored blood sample s in 1993 - 1994 ( n = 18,225 ) and 1989 - 1990 ( n = 32,826 ) , respectively , we prospect ively identified 594 incident stroke cases ( median follow-up : 8.3 y ) and matched them 1:1 to risk-set- sample d control subjects by age , sex , race , and smoking . Total plasma and red blood cell ( RBC ) fatty acids were measured by using gas-liquid chromatography . Covariates were assessed by using vali date d question naires . Stroke events and subtypes were adjudicated by using medical records or other supporting documentation . We used conditional logistic regression to estimate associations of fatty acids with incident stroke , and cohort-specific findings were combined by inverse-variance weights . RESULTS After adjustment for demographic characteristics , lifestyle , cardiovascular disease risk factors , diet , and other circulating fatty acids , no significant associations with total stroke were seen for plasma 15:0 ( pooled HR for highest compared with lowest quartiles : 0.85 ; 95 % CI : 0.54 , 1.33 ) , 17:0 ( 0.99 ; 0.67 , 1.49 ) , trans 16:1 n-7 ( 0.89 ; 0.55 , 1.45 ) , or 14:0 ( 1.05 ; 0.62 , 1.78 ) . Results were similar for ischemic and hemorrhagic stroke subtypes , for RBC fatty acids , and in several different sensitivity analyses . CONCLUSION In 2 large prospect i ve cohorts , circulating biomarkers of dairy fat were not significantly associated with stroke Background Evidence regarding the role of dairy fat intake in  cardiovascular disease (  CVD ) has been mixed and inconclusive . Most earlier studies have used self‐reported measures of dietary intake and focused on relatively racially homogeneous population s. Circulating biomarkers of dairy fat in a multiethnic cohort provide objective measures of dairy fat intake and facilitate conclusions relevant to population s with different diets and susceptibility to CVD . Methods and Results In a multiethnic cohort of 2837 US adults aged 45 to 84 years at baseline ( 2000–2002 ) , phospholipid fatty acids including 15:0 , 14:0 , and trans‐16:1n7 were measured using st and ardized methods , and the incidence of CVD prospect ively adjudicated . Self‐reported whole‐fat dairy and butter intakes had strongest associations with 15:0 , rather than 14:0 or trans‐16:1n7 . In multivariate models including demographics and lifestyle and dietary habits , each SD‐unit of 15:0 was associated with 19 % lower CVD risk ( hazard ratio [ 95 % CI ] 0.81 [ 0.68 to 0.98 ] ) and 26 % lower coronary heart disease ( CHD ) risk ( 0.74 [ 0.60 to 0.92 ] ) . Associations were strengthened after mutual adjustment for 14:0 and trans‐16:1n‐7 and were similar after adjustment for potential mediators . Plasma phospholipid 14:0 and trans‐16:1n‐7 were not significantly associated with incident CVD or CHD . All findings were similar in white , black , Hispanic , and Chinese American participants .  Conclusion Plasma phospholipid 15:0 , a biomarker of dairy fat , was inversely associated with incident CVD and CHD , while no association was found with phospholipid 14:0 and trans‐16:1n‐7 . These findings support the need for further investigation of CVD effects of dairy fat , dairy‐specific fatty acids , and dairy products in general BACKGROUND Dietary fatty acids that are more prone to oxidation than to storage may be less likely to lead to obesity . OBJECTIVE The aim of this study was to determine the effect of chain length , degree of unsaturation , and stereoisomeric effects of unsaturation on the oxidation of individual fatty acids in normal-weight men . DESIGN Fatty acid oxidation was examined in men consuming a weight-maintenance diet containing 40 % of energy as fat .  After consuming the diet for 1 wk , subjects were fed fatty acids labeled with (13)C in the methyl or carboxyl position ( 10 mg/kg body wt ) . The fatty acids fed in r and om order were laurate , palmitate , stearate , oleate , elai date ( the trans isomer of oleate ) , linoleate , and linolenate blended in a hot liquid meal . Breath sample s were collected for the next 9 h and the oxidation of each fatty acid was assessed by examining liberated (13)CO(2 ) in breath . RESULTS Cumulative oxidation over the 9-h test ranged from a high of 41 % of the dose for laurate to a low of 13 % of the dose for stearate . Of the 18-carbon fatty acids , linolenate was the most highly oxidized and linoleate appeared to be somewhat conserved . (13)C recovery in breath from the methyl-labeled fatty acids was approximately 30 % less than that from the carboxyl-labeled fatty acids . CONCLUSIONS In summary , lauric acid is highly oxidized , whereas the polyunsaturated and monounsaturated fatty acids are fairly well oxidized . Oxidation of the long-chain , saturated fatty acids decreases with increasing carbon number The aim of this study was to evaluate the association between adipose tissue trans-fatty acid isomers and  adiposity .  This cross-sectional study included 1,785 subjects from Costa Rica . Fatty acid concentrations ( as a percentage of the total fatty acids ) in subcutaneous adipose tissue were assessed by gas – liquid chromatography . Dietary intakes were assessed with a food frequency question naire . Multivariate linear regression models were used to relate adipose tissue trans-fatty acid content to BMI , waist circumference , and skinfold thickness while adjusting for age , sex , and area of residence . To account for variations in lifestyle , we adjusted for smoking , physical activity , income , self-reported history of diabetes and hypertension , and for adipose tissue alpha-linolenic acid and energy intake in a third model . After adjustments , positive associations were found between 18:2t-fatty acids ( primarily from partially hydrogenated oils ) and BMI , waist circumference , and skinfold thickness ( P for each association < 0.01 ) . Rumenic acid was positively associated with skinfold thickness ( P < 0.0001 ) , but not with BMI or waist circumference ( P > 0.05 ) . Inverse associations were found between 16:1n-7t-fatty acids and skinfold thickness and between 18:1t-fatty acids and BMI and waist circumference ( P < 0.0001 ) . This study suggests that individual trans-fatty acid isomers may have divergent effects on adiposity . 18:2t-fatty acids show consistent positive associations with measures of adiposity . These isomer-specific associations are an interesting new finding . Other prospect i ve and intervention studies are necessary to examine these relationships further BACKGROUND Although trans fatty acids ( TFAs ) may increase the risk of dyslipidemia and coronary artery disease ( CAD ) , limited data are available on their association with heart failure ( HF ) . OBJECTIVE Our goal was to assess associations of plasma and dietary TFAs with HF and CAD . DESIGN We used a prospect i ve , nested case-control design to select 788 incident HF cases and 788 matched controls from the Physicians ' Health Study for biomarker analyses and a prospect i ve cohort for the dietary analyses .  Plasma fatty acids were assessed by using gas chromatography , and dietary intake was estimated by using a food-frequency question naire . Self-reported HF was ascertained by using annual follow-up question naires with validation in a sub sample . We used conditional logistic ( or Cox ) regression to estimate multivariable-adjusted ORs ( or HRs ) for HF and CAD . RESULTS Multivariable-adjusted ORs ( 95 % CIs ) for HF across consecutive quintiles of plasma trans 18:2 ( linoleic acid ) fatty acids were 1.0 ( reference ) , 1.10 ( 0.79 , 1.54 ) , 0.88 ( 0.62 , 1.25 ) , 0.71 ( 0.49 , 1.02 ) , and 0.67 ( 0.45 , 0.98 ) ( P-trend = 0.01 ) . Each SD of plasma trans 18:2 was associated with a 22 % lower risk of HF ( 95 % CI : 6 % , 36 % ) . Plasma trans 16:1 and 18:1 were not associated with risk of HF ( P > 0.05 ) . Dietary trans fats were not associated with incident HF or CAD . CONCLUSIONS Our data are consistent with a lower risk of HF with higher concentrations of plasma trans 18:2 but not with trans 16:1 or trans 18:1 fatty acids in male physicians .  Dietary TFAs were not related to incident HF or CAD BACKGROUND Dietary fatty acids may be associated with diabetes but are difficult to measure accurately . OBJECTIVE We aim ed to investigate the associations of fatty acids in plasma and diet with diabetes incidence . DESIGN This was a prospect i ve case-cohort study of 3737 adults aged 36 - 72 y.  Fatty acid intake ( /kJ ) and plasma phospholipid fatty acids ( % ) were measured at baseline , and diabetes incidence was assessed by self-report 4 y later . Logistic regression excluding ( model 1 ) and including ( model 2 ) body mass index and waist-hip ratio was used to calculate odds ratios ( ORs ) for plasma phospholipid and dietary fatty acids . RESULTS In plasma phospholipid , positive associations with diabetes were seen for stearic acid [ OR model 1 , highest versus lowest quintile : 4.14 ( 95 % CI : 2.65 , 6.49 ) , P for trend < 0.0001 ] and total saturated fatty acids [ OR model 1 : 3.76 ( 2.43 , 5.81 ) , P for trend < 0.0001 ] , whereas an inverse association was seen for linoleic acid [ OR model 1 : 0.22 ( 0.14 , 0.36 ) , P for trend < 0.0001 ] . Dietary linoleic [ OR model 1 : 1.77 ( 1.19 , 2.64 ) , P for trend = 0.002 ] , palmitic [ OR model 1 : 1.65 ( 1.12 , 2.43 ) , P for trend = 0.012 ] , and stearic [ OR model 1 : 1.46 ( 1.00 , 2.14 ) , P for trend = 0.030 ] acids were positively associated with diabetes incidence before adjustment for body size . Within each quintile of linoleic acid intake , cases had lower baseline plasma phospholipid linoleic acid proportions than did controls . CONCLUSIONS Dietary saturated fat intake is inversely associated with diabetes risk . More research is required to determine whether linoleic acid is an appropriate dietary substitute BACKGROUND Conjugated linoleic acid ( CLA ) is a group of naturally occurring fatty acids mainly present in fats from ruminants . CLA has been shown to be a potential anticarcinogen . OBJECTIVE In this study , the relation between bovine milk fat intake and the occurrence of CLA in human adipose tissue was investigated . DESIGN One hundred twenty-three men weighed and recorded the foods they consumed for 1 wk . Afterward , recall interviews were conducted by telephone monthly for 7 consecutive months to inquire about food consumption during the previous 24 h. The entire dietary recording procedure was repeated once . The fatty acid composition of adipose tissue and serum was analyzed . RESULTS The average amount of one isomer of CLA--9-cis,11-trans-octadecadienoic acid (9c,11t-18:2)--as a percentage of total fatty acids was found to be 0.50 % in adipose tissue and 0.25 % in 
    Output:
    
agent
***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 Previous observational studies of self-reported dairy product consumption and stroke risk have reported mixed findings . Few studies have used circulating biomarkers that provide objective measures of dairy fat intake . OBJECTIVES We tested the hypothesis that the circulating biomarkers of dairy fat , pentadecanoic acid ( 15:0 ) , heptadecanoic acid ( 17:0 ) , and trans palmitoleate ( trans 16:1n-7 ) , were associated with lower incidence of stroke , especially ischemic stroke . Secondarily , we evaluated 14:0 , which is obtained from dairy products and beef , and also endogenously synthesized . DESIGN In participants from 2 large US cohorts ( the Health Professionals Follow-Up Study : 51,529 men ; the Nurses ' Health Study : 121,700 women ) with stored blood sample s in 1993 - 1994 ( n = 18,225 ) and 1989 - 1990 ( n = 32,826 ) , respectively , we prospect ively identified 594 incident stroke cases ( median follow-up : 8.3 y ) and matched them 1:1 to risk-set- sample d control subjects by age , sex , race , and smoking . Total plasma and red blood cell ( RBC ) fatty acids were measured by using gas-liquid chromatography . Covariates were assessed by using vali date d question naires . Stroke events and subtypes were adjudicated by using medical records or other supporting documentation . We used conditional logistic regression to estimate associations of fatty acids with incident stroke , and cohort-specific findings were combined by inverse-variance weights . RESULTS After adjustment for demographic characteristics , lifestyle , cardiovascular disease risk factors , diet , and other circulating fatty acids , no significant associations with total stroke were seen for plasma 15:0 ( pooled HR for highest compared with lowest quartiles : 0.85 ; 95 % CI : 0.54 , 1.33 ) , 17:0 ( 0.99 ; 0.67 , 1.49 ) , trans 16:1 n-7 ( 0.89 ; 0.55 , 1.45 ) , or 14:0 ( 1.05 ; 0.62 , 1.78 ) . Results were similar for ischemic and hemorrhagic stroke subtypes , for RBC fatty acids , and in several different sensitivity analyses . CONCLUSION In 2 large prospect i ve cohorts , circulating biomarkers of dairy fat were not significantly associated with stroke Background Evidence regarding the role of dairy fat intake in  cardiovascular disease (  CVD ) has been mixed and inconclusive . Most earlier studies have used self‐reported measures of dietary intake and focused on relatively racially homogeneous population s. Circulating biomarkers of dairy fat in a multiethnic cohort provide objective measures of dairy fat intake and facilitate conclusions relevant to population s with different diets and susceptibility to CVD . Methods and Results In a multiethnic cohort of 2837 US adults aged 45 to 84 years at baseline ( 2000–2002 ) , phospholipid fatty acids including 15:0 , 14:0 , and trans‐16:1n7 were measured using st and ardized methods , and the incidence of CVD prospect ively adjudicated . Self‐reported whole‐fat dairy and butter intakes had strongest associations with 15:0 , rather than 14:0 or trans‐16:1n7 . In multivariate models including demographics and lifestyle and dietary habits , each SD‐unit of 15:0 was associated with 19 % lower CVD risk ( hazard ratio [ 95 % CI ] 0.81 [ 0.68 to 0.98 ] ) and 26 % lower coronary heart disease ( CHD ) risk ( 0.74 [ 0.60 to 0.92 ] ) . Associations were strengthened after mutual adjustment for 14:0 and trans‐16:1n‐7 and were similar after adjustment for potential mediators . Plasma phospholipid 14:0 and trans‐16:1n‐7 were not significantly associated with incident CVD or CHD . All findings were similar in white , black , Hispanic , and Chinese American participants .  Conclusion Plasma phospholipid 15:0 , a biomarker of dairy fat , was inversely associated with incident CVD and CHD , while no association was found with phospholipid 14:0 and trans‐16:1n‐7 . These findings support the need for further investigation of CVD effects of dairy fat , dairy‐specific fatty acids , and dairy products in general BACKGROUND Dietary fatty acids that are more prone to oxidation than to storage may be less likely to lead to obesity . OBJECTIVE The aim of this study was to determine the effect of chain length , degree of unsaturation , and stereoisomeric effects of unsaturation on the oxidation of individual fatty acids in normal-weight men . DESIGN Fatty acid oxidation was examined in men consuming a weight-maintenance diet containing 40 % of energy as fat .  After consuming the diet for 1 wk , subjects were fed fatty acids labeled with (13)C in the methyl or carboxyl position ( 10 mg/kg body wt ) . The fatty acids fed in r and om order were laurate , palmitate , stearate , oleate , elai date ( the trans isomer of oleate ) , linoleate , and linolenate blended in a hot liquid meal . Breath sample s were collected for the next 9 h and the oxidation of each fatty acid was assessed by examining liberated (13)CO(2 ) in breath . RESULTS Cumulative oxidation over the 9-h test ranged from a high of 41 % of the dose for laurate to a low of 13 % of the dose for stearate . Of the 18-carbon fatty acids , linolenate was the most highly oxidized and linoleate appeared to be somewhat conserved . (13)C recovery in breath from the methyl-labeled fatty acids was approximately 30 % less than that from the carboxyl-labeled fatty acids . CONCLUSIONS In summary , lauric acid is highly oxidized , whereas the polyunsaturated and monounsaturated fatty acids are fairly well oxidized . Oxidation of the long-chain , saturated fatty acids decreases with increasing carbon number The aim of this study was to evaluate the association between adipose tissue trans-fatty acid isomers and  adiposity .  This cross-sectional study included 1,785 subjects from Costa Rica . Fatty acid concentrations ( as a percentage of the total fatty acids ) in subcutaneous adipose tissue were assessed by gas – liquid chromatography . Dietary intakes were assessed with a food frequency question naire . Multivariate linear regression models were used to relate adipose tissue trans-fatty acid content to BMI , waist circumference , and skinfold thickness while adjusting for age , sex , and area of residence . To account for variations in lifestyle , we adjusted for smoking , physical activity , income , self-reported history of diabetes and hypertension , and for adipose tissue alpha-linolenic acid and energy intake in a third model . After adjustments , positive associations were found between 18:2t-fatty acids ( primarily from partially hydrogenated oils ) and BMI , waist circumference , and skinfold thickness ( P for each association < 0.01 ) . Rumenic acid was positively associated with skinfold thickness ( P < 0.0001 ) , but not with BMI or waist circumference ( P > 0.05 ) . Inverse associations were found between 16:1n-7t-fatty acids and skinfold thickness and between 18:1t-fatty acids and BMI and waist circumference ( P < 0.0001 ) . This study suggests that individual trans-fatty acid isomers may have divergent effects on adiposity . 18:2t-fatty acids show consistent positive associations with measures of adiposity . These isomer-specific associations are an interesting new finding . Other prospect i ve and intervention studies are necessary to examine these relationships further BACKGROUND Although trans fatty acids ( TFAs ) may increase the risk of dyslipidemia and coronary artery disease ( CAD ) , limited data are available on their association with heart failure ( HF ) . OBJECTIVE Our goal was to assess associations of plasma and dietary TFAs with HF and CAD . DESIGN We used a prospect i ve , nested case-control design to select 788 incident HF cases and 788 matched controls from the Physicians ' Health Study for biomarker analyses and a prospect i ve cohort for the dietary analyses .  Plasma fatty acids were assessed by using gas chromatography , and dietary intake was estimated by using a food-frequency question naire . Self-reported HF was ascertained by using annual follow-up question naires with validation in a sub sample . We used conditional logistic ( or Cox ) regression to estimate multivariable-adjusted ORs ( or HRs ) for HF and CAD . RESULTS Multivariable-adjusted ORs ( 95 % CIs ) for HF across consecutive quintiles of plasma trans 18:2 ( linoleic acid ) fatty acids were 1.0 ( reference ) , 1.10 ( 0.79 , 1.54 ) , 0.88 ( 0.62 , 1.25 ) , 0.71 ( 0.49 , 1.02 ) , and 0.67 ( 0.45 , 0.98 ) ( P-trend = 0.01 ) . Each SD of plasma trans 18:2 was associated with a 22 % lower risk of HF ( 95 % CI : 6 % , 36 % ) . Plasma trans 16:1 and 18:1 were not associated with risk of HF ( P > 0.05 ) . Dietary trans fats were not associated with incident HF or CAD . CONCLUSIONS Our data are consistent with a lower risk of HF with higher concentrations of plasma trans 18:2 but not with trans 16:1 or trans 18:1 fatty acids in male physicians .  Dietary TFAs were not related to incident HF or CAD BACKGROUND Dietary fatty acids may be associated with diabetes but are difficult to measure accurately . OBJECTIVE We aim ed to investigate the associations of fatty acids in plasma and diet with diabetes incidence . DESIGN This was a prospect i ve case-cohort study of 3737 adults aged 36 - 72 y.  Fatty acid intake ( /kJ ) and plasma phospholipid fatty acids ( % ) were measured at baseline , and diabetes incidence was assessed by self-report 4 y later . Logistic regression excluding ( model 1 ) and including ( model 2 ) body mass index and waist-hip ratio was used to calculate odds ratios ( ORs ) for plasma phospholipid and dietary fatty acids . RESULTS In plasma phospholipid , positive associations with diabetes were seen for stearic acid [ OR model 1 , highest versus lowest quintile : 4.14 ( 95 % CI : 2.65 , 6.49 ) , P for trend < 0.0001 ] and total saturated fatty acids [ OR model 1 : 3.76 ( 2.43 , 5.81 ) , P for trend < 0.0001 ] , whereas an inverse association was seen for linoleic acid [ OR model 1 : 0.22 ( 0.14 , 0.36 ) , P for trend < 0.0001 ] . Dietary linoleic [ OR model 1 : 1.77 ( 1.19 , 2.64 ) , P for trend = 0.002 ] , palmitic [ OR model 1 : 1.65 ( 1.12 , 2.43 ) , P for trend = 0.012 ] , and stearic [ OR model 1 : 1.46 ( 1.00 , 2.14 ) , P for trend = 0.030 ] acids were positively associated with diabetes incidence before adjustment for body size . Within each quintile of linoleic acid intake , cases had lower baseline plasma phospholipid linoleic acid proportions than did controls . CONCLUSIONS Dietary saturated fat intake is inversely associated with diabetes risk . More research is required to determine whether linoleic acid is an appropriate dietary substitute BACKGROUND Conjugated linoleic acid ( CLA ) is a group of naturally occurring fatty acids mainly present in fats from ruminants . CLA has been shown to be a potential anticarcinogen . OBJECTIVE In this study , the relation between bovine milk fat intake and the occurrence of CLA in human adipose tissue was investigated . DESIGN One hundred twenty-three men weighed and recorded the foods they consumed for 1 wk . Afterward , recall interviews were conducted by telephone monthly for 7 consecutive months to inquire about food consumption during the previous 24 h. The entire dietary recording procedure was repeated once . The fatty acid composition of adipose tissue and serum was analyzed . RESULTS The average amount of one isomer of CLA--9-cis,11-trans-octadecadienoic acid (9c,11t-18:2)--as a percentage of total fatty acids was found to be 0.50 % in adipose tissue and 0.25 % in 
    Output:
    