***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: Hyperinsulinemia may explain excess colorectal cancer among individuals who are overweight or inactive . Recent studies have observed elevated colorectal cancer risk among individuals with elevated insulin levels 2 hours after oral glucose challenge or with elevated plasma C-peptide levels . The effect of consuming a high glycemic diet on colorectal risk , however , remains uncertain . Two prospect i ve cohort studies , the Nurses ' Health Study and the Health Professionals Follow-up Study , contributed up to 20 years of follow-up . After exclusions , 1,809 incident colorectal cancers were available for analyses .  Dietary glycemic load ( GL ) was calculated as a function of glycemic index ( postpr and ial blood glucose response as compared with a reference food ) , carbohydrate content , and frequency of intake of individual foods reported on food frequency question naires . Multivariable Cox proportional hazards models were used to adjust for potential confounders . Intakes of dietary carbohydrate , GL , overall glycemic index , sucrose , and fructose were not associated with  colorectal cancer risk in women . A small increase in risk was observed in men with high dietary GL ( multivariate relative risk , 1.32 ; 95 % confidence interval , 0.98 - 1.79 ; highest versus lowest quintile ) , sucrose or fructose ( multivariate relative risk , 1.37 ; 95 % confidence interval , 1.05 - 1.78 ; highest versus lowest quintile of fructose , P = 0.008 ) . Associations were slightly stronger among men with elevated body mass index ( > or = 25 kg/m(2 ) ) . Results among women were similar after stratifying by body mass index or physical activity . High intakes of GL , fructose , and sucrose were related to an elevated  colorectal cancer risk among men . For women , however , these factors did not seem to increase the risk of colorectal cancer OBJECTIVE To examine associations between type 2 diabetes and fiber , glycemic load ( GL ) , dietary glycemic index ( GI ) , and fiber-rich foods . RESEARCH DESIGN AND METHODS This was a prospect i ve study of 36,787 men and women aged 40 - 69 years without diabetes . For all self-reported cases of diabetes at 4-year follow-up , confirmation of diagnosis was sought from medical practitioners . Case subjects were those who reported diabetes at follow-up and for whom there was no evidence that they did not have type 2 diabetes . Data were analyzed with logistic regression , adjusting for country of birth , physical activity , family history of diabetes , alcohol and energy intake , education , 5-year weight change , sex , and age . RESULTS Follow-up was completed by 31,641 ( 86 % ) participants , and 365 cases were identified . The odds ratio ( OR ) for the highest quartile of white bread intake compared with the lowest was 1.37 ( 95 % CI 1.04 - 1.81 ; P for trend = 0.001 ) . Intakes of carbohydrate ( OR per 200 g/day 0.58 , 0.36 - 0.95 ) , sugars ( OR per 100 g/day 0.61 , 0.47 - 0.79 ) , and magnesium ( OR per 500 mg/day 0.62 , 0.43 - 0.90 ) were inversely associated with incidence of diabetes , whereas intake of starch ( OR per 100 g/day 1.47 , 1.06 - 2.05 ) and dietary GI ( OR per 10 units 1.32 , 1.05 - 1.66 ) were positively associated with diabetes . These relationships were attenuated after adjustment for BMI and waist-to-hip ratio . CONCLUSIONS Reducing dietary GI while maintaining a high carbohydrate intake may reduce the risk of type 2 diabetes . One way to achieve this would be to substitute white bread with low-GI breads BACKGROUND Little is known about the effects of the amount and type of carbohydrates on risk of coronary heart disease ( CHD ) .  OBJECTIVE The objective of this study was to prospect ively evaluate the relations of the amount and type of carbohydrates with risk of CHD . DESIGN A cohort of 75521 women aged 38 - 63 y with no previous diagnosis of diabetes mellitus , myocardial infa rct ion , angina , stroke , or other cardiovascular diseases in 1984 was followed for 10 y. Each participant 's dietary glycemic load was calculated as a function of glycemic index , carbohydrate content , and frequency of intake of individual foods reported on a vali date d food-frequency question naire at baseline . All dietary variables were up date d in 1986 and 1990 . RESULTS During 10 y of follow-up ( 729472 person-years ) , 761 cases of CHD ( 208 fatal and 553 nonfatal ) were documented . Dietary glycemic load was directly associated with risk of CHD after adjustment for age , smoking status , total energy intake , and other coronary disease risk factors . The relative risks from the lowest to highest quintiles of glycemic load were 1.00 , 1.01 , 1 . 25 , 1.51 , and 1.98 ( 95 % CI : 1.41 , 2.77 for the highest quintile ; P for trend < 0.0001 ) . Carbohydrate classified by glycemic index , as opposed to its traditional classification as either simple or complex , was a better predictor of CHD risk . The association between dietary glycemic load and CHD risk was most evident among women with body weights above average ¿ ie , body mass index ( in kg/m(2 ) ) > /= 23 . CONCLUSION These epidemiologic data suggest that a high dietary glycemic load from refined carbohydrates increases the risk of CHD , independent of known coronary disease risk factors BACKGROUND Dietary carbohydrates may influence the development of  type 2 ( non-insulin-dependent ) diabetes  , for example , through effects on blood glucose and insulin concentrations . OBJECTIVE We examined the relations of baseline intake of carbohydrates , dietary fiber , dietary magnesium , and carbohydrate-rich foods and the glycemic index with incidence of diabetes . DESIGN This was a prospect i ve cohort study of 35988 older Iowa women initially free of diabetes . During 6 y of follow-up , 1141 incident cases of diabetes were reported . RESULTS  Total grain , whole-grain , total dietary fiber , cereal fiber , and dietary magnesium intakes  showed strong inverse associations with incidence of diabetes after adjustment for potential nondietary confounding variables . Multivariate-adjusted relative risks of diabetes were 1.0 , 0.99 , 0.98 , 0.92 , and 0.79 ( P for trend : 0.0089 ) across quintiles of whole-grain intake ; 1.0 , 1.09 , 1.00 , 0.94 , and 0.78 ( P for trend : 0.005 ) across quintiles of total dietary fiber intake ; and 1.0 , 0.81 , 0.82 , 0.81 , and 0.67 ( P for trend : 0.0003 ) across quintiles of dietary magnesium intake . Intakes of total carbohydrates , refined grains , fruit and vegetables , and soluble fiber and the glycemic index were unrelated to diabetes risk . CONCLUSION These data support a protective role for grains ( particularly whole grains ) , cereal fiber , and dietary magnesium in the development of diabetes in older women BACKGROUND Metabolism of many of the most commonly consumed carbohydrates in the United States results in a high plasma glucose response , which can be quantified by the glycemic load . Although hyperglycemia is a risk factor for cataract , there is no information on the potential effect of a high dietary glycemic load on the incidence of age-related cataract . OBJECTIVE Our objective was to prospect ively examine the association between dietary glycemic load and incident age-related cataract . DESIGN We studied 2 cohorts-71 919 women and 39 926 men-aged > or = 45 y who had no previous diagnosis of cataract , diabetes mellitus , or cancer and who were followed for 14 and 12 y , respectively , for the occurrence of cataract extraction . We calculated dietary glycemic load from data reported on multiple vali date d food-frequency question naires and used pooled logistic regression models to estimate the association with incident cataract extraction . We performed analyses separately for each cohort and then calculated pooled estimates across cohorts . RESULTS During 980 683 person-years of follow-up , we confirmed 4865 incident age-related cataract extraction s.  After adjustment for age , cigarette smoking , body mass index , total caloric intake , dietary intake of lutein and zeaxanthin , and alcohol consumption , there was no significant relation of dietary glycemic load to risk of cataract extraction ( P for trend = 0.10 ) . The pooled relative risk between the highest and lowest quintiles of dietary glycemic load was 0.95 ( 95 % CI : 0.81 , 1.11 ; P for heterogeneity by cohort = 0.1 ) . CONCLUSION These prospect i ve epidemiologic data do not support the hypothesis that a high dietary glycemic load , primarily a result of consumption of refined carbohydrates , increases the risk of cataract extraction BACKGROUND Reducing the glycemic load ( GL ) is considered beneficial for managing insulin resistance . The GL can be reduced either by reducing carbohydrate intake or by reducing the glycemic index ( GI ) . OBJECTIVE We studied whether these 2 dietary maneuvers have the same long-term effects on postpr and ial plasma glucose , insulin , triacylglycerol , and free fatty acid ( FFA ) concentrations in subjects with impaired glucose tolerance ( IGT ) . DESIGN Thirty-four subjects with IGT were r and omly assigned to high-carbohydrate , high-GI ( high-GI ) ; high-carbohydrate , low-GI ( low-GI ) ; and low-carbohydrate , high-monounsaturated fatty acid ( MUFA ) diets for 4 mo . Plasma glucose , insulin , and FFAs were measured from 0800 to 1600 at baseline in response to high-GI meals ( 60 % carbohydrate , GI = 61 , GL = 63 ) and after 4 mo in response to meals representative of the study diet . RESULTS Carbohydrate intake ( % of energy ) , GI , and GL in the high-GI , low-GI , and MUFA groups ( breakfast and lunch meals combined ) , respectively , were 60 % , 61 , and 63 ; 60 % , 53 , and 55 ; and 49 % , 61 , and 52 . Compared with the change after 4 mo of the high-GI diet , both the low-GI and MUFA diets reduced 0 - 8-h mean plasma glucose concentrations by 0.35 mmol/L ( P < 0.05 ) . Mean plasma insulin was approximately 20 % higher ( P < 0.05 ) and FFAs approximately 12 % lower ( P < 0.05 ) after the low-GI diet than after the high-GI diet , with no significant effect of MUFA . Changes in 0 - 8-h mean plasma triacylglycerols in the 3 treatment groups differed significantly : -0.14 , 0.04 , and 0.18 mmol/L , respectively , with the high-GI , MUFA , and low-GI diets . CONCLUSIONS In subjects with IGT , reducing the GI of the diet for 4 mo reduced postpr and ial plasma glucose by the same amount as did reducing carbohydrate intake . The 2 dietary maneuvers had different effects on postpr and ial plasma insulin , triacylglycerols , and FFAs BACKGROUND Increasing evidence suggests an important role of carbohydrate quality in the development of type 2 diabetes . OBJECTIVE Our objective was to prospect ively examine the association between glycemic index , glycemic load , and dietary fiber and the risk of type 2 diabetes in a large cohort of young women . DESIGN In 1991 , 91249 women completed a semiquantitative food-frequency question naire that assessed dietary intake .  The women were followed for 8 y for the development of incident type 2 diabetes , and dietary information was up date d in 1995 . RESULTS We identified 741 incident cases of confirmed type 2 diabetes during 8 y ( 716 300 person-years ) of follow-up . After adjustment for age , body mass index , family history of diabetes , and other potential confounders 
    Output:
    
Low-GI and /or low-GL diets are independently associated with a reduced risk of certain chronic diseases .
In diabetes and heart disease , the protection is comparable with that seen for whole grain and high fiber intakes .
The findings support the hypothesis that higher postpr and ial glycemia is a universal mechanism for disease progression