***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: 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 quality alone could alter insulin action in humans . Methods . The KANWU study included 162 healthy subjects chosen at r and om to receive a controlled , isoenergetic diet for 3 months containing either a high proportion of saturated ( SAFA diet ) or monounsaturated ( MUFA diet ) fatty acids . Within each group there was a second assignment at r and om to supplements with fish oil ( 3.6 g n-3 fatty acids/d ) or placebo . Results . Insulin sensitivity was significantly impaired on the saturated fatty acid diet ( -10 % , p = 0.03 ) but did not change on the monounsaturated fatty acid diet ( + 2 % , NS ) ( p = 0.05 for difference between diets ) . Insulin secretion was not affected . The addition of n-3 fatty acids influenced neither insulin sensitivity nor insulin secretion . The favourable effects of substituting a monounsaturated fatty acid diet for a saturated fatty acid diet on insulin sensitivity were only seen at a total fat intake below median ( 37E % ) . Here , insulin sensitivity was 12.5 % lower and 8.8 % higher on the saturated fatty acid diet and monounsaturated fatty acid diet respectively ( p = 0.03 ) . Low density lipoprotein cholesterol ( LDL ) increased on the saturated fatty acid diet ( + 4.1 % , p < 0.01 ) but decreased on the monounsaturated fatty acid diet ( MUFA ) ( –5.2 , p < 0.001 ) , whereas lipoprotein ( a ) [ Lp(a ) ] increased on a monounsaturated fatty acid diet by 12 % ( p < 0.001 ) . Conclusions /interpretation . A change of the proportions of dietary fatty acids , decreasing saturated fatty acid and increasing monounsaturated fatty acid , improves insulin sensitivity but has no effect on insulin secretion . A beneficial impact of the fat quality on insulin sensitivity is not seen in individuals with a high fat intake ( > 37E % ) . [ Diabetologia ( 2001 ) 44 : 312–319 Meat contains numerous carcinogens , such as heterocyclic amines , polycyclic aromatic hydrocarbons , and N‐nitroso compounds , which can be derived either from natural food or during the process of food preparation . These carcinogens may increase pancreatic cancer risk . Furthermore , studies in animals showed that polyunsaturated fatty acids , especially linoleic acid , increase pancreatic cancer risk . We examined prospect ively the relation between pancreatic cancer risk and intake of fresh meat , processed meat , fish , eggs , total fat , and different types of fat . The Netherl and s Cohort Study consisted of 120,852 men and women who completed a baseline question naire in 1986 . After 13.3 years of follow‐up , 350 pancreatic cancer cases ( 66 % microscopically confirmed ) were available for analysis . A vali date d 150‐item food‐frequency question naire was used to calculate intake of fresh meat , processed meat , fish , eggs , fat and different types of fat .  No association was found when examining the association between intake of fresh meat , other types of meat , fish , eggs , dietary intake of total fat and different types of fat  and risk of pancreatic cancer . It is important for future studies to investigate the relation between different meat‐cooking methods  and pancreatic cancer . © 2009 Case-control studies suggest that meat and cholesterol intakes may be related to elevated risks of pancreatic cancer . Few prospect i ve studies have examined associations between diet and pancreatic cancer , although in one recent study saturated fat consumption was related to higher risk . In a cohort of US women , the authors confirmed 178 pancreatic cancer cases over 18 years of follow-up . A mailed 61-item food frequency question naire was self-administered at baseline , and health and lifestyle variables were up date d biennially . Analyses were performed using Cox proportional hazards models to adjust for potential confounders . Intakes of total fat , different types of fats , and cholesterol were not associated with pancreatic cancer risk . Similarly , total meat , red meat , and dairy products were not related to risk . Individual food items contributing to intakes of total meat and dairy products , as well as fish and eggs , did not reveal any specific association . Updating dietary exposures by using question naires from 1980 , 1984 , 1986 , and 1990 produced similar findings . The authors ' data do not support previous findings that meat or saturated fat intakes are related to pancreatic cancer risk . Future prospect i ve studies should examine the influence of cooking practice s as well as other dietary habits on the risk of pancreatic cancer BACKGROUND Previous research relating dietary fat , a modifiable risk factor , to pancreatic cancer has been inconclusive . METHODS We prospect ively analyzed the association between intakes of fat , fat subtypes , and fat food sources and exocrine pancreatic cancer in the National Institutes of Health-AARP Diet and Health Study , a US cohort of 308 736 men and 216 737 women who completed a 124-item food frequency question naire in 1995 - 1996 .  Hazard ratios ( HRs ) and 95 % confidence intervals ( CIs ) were calculated using Cox proportional hazards regression models , with adjustment for energy intake , smoking history , body mass index , and diabetes . Statistical tests were two-sided . RESULTS Over an average follow-up of 6.3 years , 865 men and 472 women were diagnosed with exocrine pancreatic cancer ( 45.0 and 34.5 cases per 100 000 person-years , respectively ) . After multivariable adjustment and combination of data for men and women , pancreatic cancer risk was directly related to the intakes of total fat ( highest vs lowest quintile , 46.8 vs 33.2 cases per 100 000 person-years , HR = 1.23 , 95 % CI = 1.03 to 1.46 ; P(trend ) = .03 ) , saturated fat ( 51.5 vs 33.1 cases per 100 000 person-years , HR = 1.36 , 95 % CI = 1.14 to 1.62 ; P(trend ) < .001 ) , and monounsaturated fat ( 46.2 vs 32.9 cases per 100 000 person-years , HR = 1.22 , 95 % CI = 1.02 to 1.46 ; P(trend ) = .05 ) but not polyunsaturated fat . The associations were strongest for saturated fat from animal food sources ( 52.0 vs 32.2 cases per 100 000 person-years , HR = 1.43 , 95 % CI = 1.20 to 1.70 ; P(trend ) < .001 ) ; specifically , intakes from red meat and dairy products were both statistically significantly associated with increased pancreatic cancer risk ( HR = 1.27 and 1.19 , respectively ) . CONCLUSION In this large prospect i ve cohort with a wide range of intakes , dietary fat of animal origin was associated with increased pancreatic cancer risk A case-control study was conducted in the Minneapolis-St Paul ( Minnesota , United States ) area to assess the role of dietary factors in the etiology of pancreatic cancer . Cases were White males aged 40 to 84 whose death certificate listed pancreatic cancer ( exocrine only ) . White male controls were ascertained through r and om-digit dialing . Family members were interviewed about the subject 's dietary usage in the two years prior to death ( cases , n=212 ) or prior to interview ( controls , n=220 ) . Energy-adjusted , nutrient-intake , risk estimates were calculated . Among all respondents , negative trends were observed for polyunsaturated fat , linoleic acid , vitamin C , and β-carotene . Positive trends were observed for riboflavin and retinol . Point estimates were , in general , comparable between the analyses of all respondents and spouse-only respondents . The nutrients associated with a decreased risk for pancreatic cancer occur primarily in vegetables and fruits , of which the consumption of cruciferous and β-carotene-rich vegetables and citrus fruits provided the greatest reduction in risk To examine the relation between diet and pancreatic cancer , we conducted a population -based case-control study in western Washington . Cases ( n = 148 ) were married men , aged 20 - 74 years , who were diagnosed with pancreatic cancer from July 1982 to June 1986 . Controls ( n = 188 ) , identified by r and om digit dialing , were frequency matched to the cases by 5-year age groups . Wives responded as surrogates for both cases and controls . Wives were interviewed by telephone , and they completed a mailed , self-administered food frequency question naire . Results indicated that pancreatic cancer risk increased with increasing protein intake . The increased risk for heavy consumers of protein was largely confined to individuals aged 65 years and above . In that group , the odds ratio for those in the highest quartile of protein intake , relative to the lowest , was 6.0 ( 95 % confidence interval 1.7 - 20.6 ) . No association was found between pancreatic cancer risk and the intake of total fat , saturated fat , cholesterol , omega-3 fatty acids , or  vitamins A and C. There was an unexpected inverse association between calcium intake and pancreatic cancer risk in these data . These findings are discussed in relation to possible etiologic mechanisms that they suggest Background Few epidemiologic studies have examined the role of nutrient intake in the development of pancreatic cancer in Japan . We addressed this association in a population -based case-control study . Methods The cases were 109 patients who were newly diagnosed with pancreatic cancer between January 2000 and March 2002 , and controls were selected by a r and om procedure from the general population . Data on  dietary intake  were collected by in-person interview , with the use of a food-frequency question naire . The risk of pancreatic cancer associated with nutrient intake was estimated by using the odds ratios ( ORs ) and 95 % confidence intervals ( CIs ) derived from a conditional logistic model . Results A statistically positive trend in risk was observed with increasing cholesterol intake , with subjects in the highest tertile experiencing a two fold increased risk ( OR , 2.06 ; 95 % CI , 1.11–3.85 ; Ptrend = 0.02 ) . Vitamin C intake  was negatively associated with risk of pancreatic cancer . The OR was 0.45 ( 95 % CI , 0.22–0.94 ) for subjects in the highest tertile compared to the lowest tertile ( Ptrend = 0.04 ) . Conclusions Our study indicates that high cholesterol intake is significantly associated with an increased risk of pancreatic cancer and that high vitamin C intake decreases the risk of pancreatic cancer BACKGROUND Meat intake has been associated with risk of  exocrine pancreatic cancer  , but previous findings have been inconsistent . This association has been attributed to both the fat and cholesterol content of meats and to food preparation methods . We analyzed data from the prospect i ve Multiethnic Cohort Study to investigate associations between intake of meat , other animal products , fat , and cholesterol and pancreatic cancer risk . METHODS During 7 years of follow-up , 482 incident pancreatic cancers occurred in 190,545 cohort members .  Dietary intake  was assessed using a quantitative food frequency question naire . Associations for foods and nutrients relative to total energy intake were determined by Cox proportional hazards models stratified by gender and time on study and adjusted for age , smoking status , history of diabetes mellitus and familial pancreatic cancer , ethnicity , and energy intake . Statistical tests were two-sided . RESULTS The strongest association was with processed meat ; those in the fifth quintile of daily intake ( g/1000 kcal ) had a 68 % increased risk compared with those in the lowest quintile ( relative risk = 1.68 , 95 % confidence interval = 1.35 to 2.07 ; Ptrend < .01 ) . The age-adjusted yearly incidence rates per 100,000 persons for the respective quintiles were 41.3 and 20.2 . Intakes of pork and of total red meat were both associated with 50 % increases in risk , comparing the highest with the lowest quintiles ( both Ptrend < .01 ) . There were no associations of pancreatic cancer risk with intake of poultry , fish , dairy products , eggs , total fat , saturated fat , or cholesterol . Intake of total and saturated fat from meat was associated with statistically significant increases in pancreatic cancer risk but that from dairy products was not . CONCLUSION Red and processed meat intakes were associated with an increased risk of pancreatic cancer . Fat and saturated fat are not likely to contribute to the underlying carcinogenic mechanism because the findings for fat from meat and dairy products differed . Carcinogenic substances related to meat preparation methods might be responsible for the positive association Although mounting evidence suggests that insulin resistance is involved in pancreatic carcinogenesis 
    Output:
    
There was no evidence of publication bias or significant heterogeneity between subgroups on meta-regression analyses .
The results of this meta- analysis do not support an independent association between diets high in total fat and pancreatic cancer risk