***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: Epidemiologic data and animal experiments suggest that dietary fat may influence risk of  breast cancer .  To determine whether intervention with a low-fat , high-carbohydrate diet would reduce breast cancer incidence in women at increased risk of the disease , we carried out a r and omized controlled trial in Canada . We recruited 4,690 women with extensive mammographic density and r and omized them to an intervention group or a comparison group . The intervention group received intensive dietary counseling to reduce fat intake to a target of 15 % of calories and increase carbohydrate to 65 % of calories . Dietary intakes were assessed throughout using food records . Subjects were followed for at least 7 years and for an average of 10 years . The main outcome was invasive breast cancer . Percentage of calories from fat in the intervention group decreased from 30 % at baseline to 20 % after r and omization and remained 9 % to 10 % lower than the comparison group throughout . There were 118 invasive breast cancers in the intervention group and 102 in the comparison group [ adjusted hazard ratio = 1.19 ( 95 % CI : 0.91 - 1.55 ) ] . Analysis of food records showed that fat intake at baseline and after r and omization was not associated with total breast cancer incidence . Greater weight and lower carbohydrate intake at baseline and after r and omization were associated with an increased risk of estrogen receptor (ER)-positive breast cancer . Our findings suggest that a sustained reduction in dietary fat intake did not reduce risk of breast cancer  in women with extensive mammographic density .  Weight and carbohydrate intakes were associated with risk of ER-positive breast cancer Abstract Background Diabetes prevalence is increasing . The Finnish Diabetes Prevention Study ( DPS ) showed a 58 % reduction in Type 2 Diabetes ( T2D ) incidence in adults with impaired glucose tolerance ( IGT ) . The European Diabetes Prevention Study ( EDIPS ) extends the DPS to different European population s , using the same study design . In the Newcastle arm of this study ( EDIPS-Newcastle ) , we tested the hypothesis that T2D can be prevented by lifestyle intervention and explored secondary outcomes in relation to diabetes incidence . Methods We recruited 102 participants ( 42 men and 60 women , mean age 57 years , mean BMI 34 kgm-2 ) with IGT to EDIPS-Newcastle and r and omised to Intervention and usual care Control groups .  The intervention included individual motivational interviewing aim ed at : weight reduction , increase in physical activity , fibre and carbohydrate intake and reduction of fat intake ( secondary outcomes ) . The primary outcome was diagnosis of T2D . Results Mean duration of follow-up was 3.1 years . T2D was diagnosed in 16 participants ( I = 5 , C = 11 ) . Absolute incidence of T2D was 32.7 per 1000 person-years in the Intervention-group and 67.1 per 1000 person-years in the Control-group . The overall incidence of diabetes was reduced by 55 % in the Intervention-group , compared with the Control-group : RR 0.45 ( 95%CI 0.2 to 1.2).Explanatory survival analysis of secondary outcomes showed that those who sustained beneficial changes for two or more years reduced their risk of developing T2D . Conclusion Our results are consistent with other diabetes prevention trials . This study was design ed as part of a larger study and although the sample size limits statistical significance , the results contribute to the evidence that T2D can be prevented by lifestyle changes in adults with IGT . In explanatory analysis small sustained beneficial changes in weight , physical activity or dietary factors were associated with reduction in T2D incidence . Trial Registration International St and ard R and omised Controlled Trial Number registry ( IS RCT N)Registry number : IS RCT N 15670600 http://www.controlled-trials.com/is rct n/ search .html?srch=15670600%26sort=3%26dir = This double-blind , r and omized crossover study investigated the effects of 6 weeks of treatment with prescription omega-3-acid ethyl esters ( POM3 , 4 g/day ) versus placebo ( soy oil ) on low-density lipoprotein cholesterol ( LDL-C ) and other aspects of the fasting lipid profile in 31 men and women with primary , isolated hypercholesterolemia ( LDL-C 130 - 220 mg/dL and triglycerides less than 150 mg/dL while free of lipid-altering therapies ) . Mean ± st and ard error of the mean baseline concentrations of total cholesterol , LDL-C , high-density lipoprotein cholesterol ( HDL-C ) , very-low-density lipoprotein cholesterol , and triglycerides were 229 ± 3 , 146 ± 3 , 60 ± 2 , 23 ± 2 , and 113 ± 8 mg/dL , respectively . POM3 produced a modest increase from baseline in LDL-C ( 3.4 % ) versus the placebo response ( -0.7 % , P = 0.010 ) . Significant changes ( P < 0.05 ) for POM3 ( placebo-corrected ) were observed for very-low-density lipoprotein cholesterol ( -18.8 % ) , triglycerides ( -18.7 % ) , and HDL-C ( 3.3 % ) . Nuclear magnetic resonance-determined very-low-density lipoprotein particle concentration and size and HDL particle concentration decreased significantly more with POM3 versus placebo , whereas LDL and HDL particle sizes increased significantly more with POM3 versus placebo . Total cholesterol , non-HDL-C , apolipoproteins A1 and B , and LDL particle concentration responses did not differ between treatments . These results did not confirm the hypothesis that POM3 treatment would lower LDL-C in primary , isolated hypercholesterolemia . Effects on other variables were consistent with prior results in mixed dyslipidemia Background —Consumption of polyunsaturated fatty acids ( PUFAs ) may reduce coronary heart disease ( CHD ) risk , but n-6 PUFAs may compete with n-3 PUFA metabolism and attenuate benefits . Additionally , seafood-based , long-chain n-3 PUFAs may modify the effects of plant-based , intermediate-chain n-3 PUFAs . However , the interactions of these PUFAs in relation to CHD risk are not well established . Methods and Results —Among 45 722 men free of known cardiovascular disease in 1986 , usual dietary intake was assessed at baseline and every 4 years by using vali date d food-frequency question naires . CHD incidence was prospect ively ascertained . Over 14 years of follow-up , participants experienced 218 sudden deaths , 1521 nonfatal myocardial infa rct ions ( MIs ) , and 2306 total CHD events ( combined sudden death , other CHD deaths , and nonfatal MI ) . In multivariate-adjusted analyses , both long-chain and intermediate-chain n-3 PUFA intakes were associated with lower CHD risk , without modification by n-6 PUFA intake . For example , men with ≥ median long-chain n-3 PUFA intake ( ≥250 mg/d ) had a reduced risk of sudden death whether n-6 PUFA intake was below ( < 11.2 g/d ; hazard ratio [HR]=0.52 ; 95 % confidence interval [CI]=0.34 to 0.79 ) or above ( ≥11.2 g/d ; HR=0.60 ; 95 % CI=0.39 to 0.93 ) the median compared with men with a < median intake of both . In similar analyses , ≥ median intake of intermediate-chain n-3 PUFAs ( ≥1080 mg/d ) was associated with a reduced total CHD risk whether n-6 PUFA intake was lower ( HR=0.88 ; 95 % CI=0.78 to 0.99 ) or higher ( HR=0.89 ; 95 % CI=0.79 to 0.99 ) compared with a < median intake of both . Intermediate-chain n-3 PUFAs were particularly associated with CHD risk when long-chain n-3 PUFA intake was very low ( < 100 mg/d ) ; among these men , each 1 g/d of intermediate-chain n-3 PUFA intake was associated with an ≈50 % lower risk of nonfatal MI ( HR=0.42 ; 95 % CI=0.23 to 0.75 ) and total CHD ( HR=0.53 ; 95 % CI=0.34 to 0.83 ) . Conclusions —n-3 PUFAs from both seafood and plant sources may reduce CHD risk , with little apparent influence from background n-6 PUFA intake . Plant-based n-3 PUFAs may particularly reduce CHD risk when seafood-based n-3 PUFA intake is low , which has implication s for population s with low consumption or availability of fatty fish BACKGROUND Epidemiologic studies of dietary fat and breast cancer risk are inconsistent , and it has been suggested that a true relation may have been obscured by the imprecise measurement of fat intake . OBJECTIVE We examined associations of fat with breast cancer risk by using estimates of fat intake from food diaries and food-frequency question naires ( FFQs ) pooled from 4 prospect i ve studies in the United Kingdom . DESIGN A total of 657 cases of breast cancer in premenopausal and postmenopausal women were matched on study , age , and recruitment date with 1911 control subjects .  Nutrient intakes were estimated from food diaries and FFQs . Conditional logistic regression was used to estimate ORs for breast cancer associated with total , saturated , monounsaturated , and polyunsaturated fat intakes with adjustment for relevant covariates . RESULTS Neither the food diaries nor the FFQs showed any positive associations between fat intake and overall breast cancer risk . ORs ( 95 % CIs ) for the highest compared with lowest quintiles of percentage of energy from total fat were 0.90 ( 0.66 , 1.23 ) for food diaries and 0.80 ( 0.59 , 1.09 ) for FFQs . CONCLUSION In this study , breast cancer risk was not associated with fat  intake in middle-aged women in the United Kingdom , irrespective of whether diet was measured by food diaries or by FFQs CONTEXT Observational studies and polyp recurrence trials are not conclusive regarding the effects of a low-fat dietary pattern on risk of colorectal cancer , necessitating a primary prevention trial . OBJECTIVE To evaluate the effects of a low-fat eating pattern on risk of colorectal cancer in postmenopausal women . DESIGN , SETTING , AND PARTICIPANTS The Women 's Health Initiative Dietary Modification Trial , a r and omized controlled trial conducted in 48,835 postmenopausal women aged 50 to 79 years recruited between 1993 and 1998 from 40 clinical centers throughout the United States . INTERVENTIONS Participants were r and omly assigned to the  dietary modification intervention  ( n = 19,541 ; 40 % ) or the  comparison group  ( n = 29,294 ; 60 % ) . The intensive behavioral modification program aim ed to motivate and support reductions in dietary fat , to increase consumption of vegetables and fruits , and to increase grain servings by using group sessions , self-monitoring techniques , and other tailored and targeted strategies . Women in the comparison group continued their usual eating pattern . MAIN OUTCOME MEASURE Invasive colorectal cancer incidence . RESULTS A total of 480 incident cases of invasive colorectal cancer occurred during a mean follow-up of 8.1 ( SD , 1.7 ) years . Intervention group participants significantly reduced their percentage of energy from fat by 10.7 % more than did the comparison group at 1 year , and this difference between groups was mostly maintained ( 8.1 % at year 6 ) . Statistically significant increases in vegetable , fruit , and grain servings were also made . Despite these dietary changes , there was no evidence that the intervention reduced the risk of invasive colorectal cancer during the follow-up period . There were 201 women with invasive colorectal cancer ( 0.13 % per year ) in the intervention group and 279 ( 0.12 % per year ) in the comparison group ( hazard ratio , 1.08 ; 95 % confidence interval , 0.90 - 1.29 ) . Secondary analyses suggested potential interactions with baseline aspirin use and combined estrogen-progestin use status ( P = .01 for each ) . Colorectal examination rates , although not protocol defined , were comparable between the intervention and comparison groups . Similar results were seen in analyses adjusting for adherence to the intervention . CONCLUSION In this study , a low-fat dietary pattern intervention did not reduce the risk of colorectal cancer  in postmenopausal women during 8.1 years of follow-up . CLINICAL TRIALS REGISTRATION Clinical Trials.gov Identifier : NCT00000611 Aims /hypothesis . The amount and quality of fat in the diet could be of importance for development of insulin resistance and related metabolic disorders . Our aim was to determine whether a change in dietary fat 
    Output:
    
Convincing evidence was found that partial replacement of saturated fat ( SFA ) with polyunsaturated fat ( PUFA ) or monounsaturated fat ( MUFA ) lowers fasting serum/plasma total and LDL cholesterol concentrations .
The evidence was probable for a decreasing effect of fish oil on concentration of serum/plasma total triglycerides as compared with MUFA .
Beneficial effect of MUFA both on insulin sensitivity and fasting plasma/serum insulin concentration was considered as probable in comparisons of MUFA and carbohydrates versus SFA , whereas no effect was found on fasting glucose concentration in these comparisons .
There was probable evidence for a moderate direct association between total fat intake and BW .
Furthermore , there was convincing evidence that partial replacement of SFA with PUFA decreases the risk of CVD , especially in men .
This finding was supported by an association with biomarkers of PUFA intake ; the evidence of a beneficial effect of dietary total PUFA , n-6 PUFA , and linoleic acid ( LA ) on CVD mortality was limited suggestive .
Evidence for a direct association between total fat intake and risk of T2DM was inconclusive , whereas there was limited-suggestive evidence from biomarker studies that LA is inversely associated with the risk of T2DM .
However , there was limited-suggestive evidence in biomarker studies that odd-chain SFA found in milk fat and fish may be inversely related to T2DM , but these associations have not been supported by controlled studies .
The evidence for an association between dietary n-3 PUFA and T2DM was inconclusive .