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 Green tea is one of the most popular beverages worldwide . This review summarizes the beneficial effects of green tea on cancer prevention . Methods Electronic data bases , including PubMed ( 1966–2008 ) , the Cochrane Library ( Issue 1 , 2008 ) and Chinese Biomedical Data base ( 1978–2008 ) with supplement of relevant websites , were search ed . There was no language restriction . The search es ended at March 2008 . We included r and omized and non-r and omized clinical trials , epidemiological studies ( cohort and case-control ) and a meta- analysis . We excluded case series , case reports , in vitro and animal studies . Outcomes were measured with estimation of relative risk , hazard or odd ratios , with 95 % confidence interval . Results Forty-three epidemiological studies , four r and omized trials and one meta- analysis were identified . The overall quality of these studies was evaluated as good or moderate . While some evidence suggests that green tea has beneficial effects on gastrointestinal cancers , the findings are not consistent . Conclusion Green tea may have beneficial effects on cancer prevention . Further studies such as large and long term cohort studies and clinical trials are warranted BACKGROUND Green tea is one of the most popular beverages in the world . It is believed to have beneficial effects in the prevention and treatment of many diseases , one of which is type 2 diabetes . The aim of the study is to examine the effect of a decaffeinated green tea extract ( GTE ) providing a daily dose of 856 mg of epigallocatechin gallate ( EGCG ) on obese individuals with type 2 diabetes . MATERIAL S AND METHODS The clinical trial was a r and omized , double-blind , placebo-controlled clinical trial conducted from December 2007 through November 2008 . The subjects were r and omly assigned to either receive 1,500 mg of a decaffeinated GTE or placebo daily for 16 weeks . Sixty-eight of 80 subjects , ages 20 - 65 years with BMI > 25 kg/m2 and type 2 diabetes for more than one year , completed this study .  Homeostasis model assessment for insulin resistance ( HOMA-IR ) was used as the major outcome measurement . At baseline and after 16 weeks of treatment , anthropometric measurements , fasting glucose , hemoglobin A1C percent ( HbA1C ) , hormone peptides , and plasma lipoproteins were measured from both groups . RESULTS No statistically significant differences were detected between the decaffeinated GTE and placebo groups in any measured variable . A statistically significant within-group 0.4-percent reduction in HbA1C ( from 8.4 to 8.0 % ) was observed after GTE treatment compared to baseline . Within-group comparison also revealed that the GTE group had significant reductions in waist circumference ( WC ) , HOMA-IR index , and insulin level , and a significant increase in the level of ghrelin . Within-group comparison of those in the placebo group showed a significant increase in the level of ghrelin . CONCLUSIONS This study found no statistical difference in any measured variable between the decaffeinated GTE and placebo groups ; however , there were some statistically significant within-group changes detected . More research is required to determine whether a decaffeinated GTE st and ardized for EGCG content will provide any clinical benefits in obese individuals with type 2 diabetes . Clinical Trial Registration NO : NCT00567905 Objectives : The development of obesity is characterized by an increase in adipose tissue mass and by concomitant and profound changes in almost all organ functions leading to diseases such as hypertension , diabetes mellitus and coronary heart disease . Recent data from human studies indicate that the consumption of green tea and green tea extracts may help reduce body weight , mainly body fat , by increasing postpr and ial thermogenesis and fat oxidation . However , human studies investigating the metabolic effects of the most predominant tea catechin , EGCG , alone are absent . Methods : In a r and omized double blind , placebo-controlled , cross-over pilot study , six overweight men were given 300 mg EGCG/d for 2d . Fasting and postpr and ial changes in energy expenditure ( EE ) and substrate oxidation were assessed . Results : Resting EE did not differ significantly between EGCG and placebo treatments , although during the first postpr and ial monitoring phase , respiratory quotient ( RQ ) values were significantly lower with EGCG compared to the placebo . Conclusions : These findings suggest that EGCG alone has the potential to increase fat oxidation in men and may thereby contribute to the anti-obesity effects of green tea . However , more studies with a greater sample size and a broader range of age and BMI are needed to define the optimum dose BACKGROUND Increasing coffee intake was inversely associated with risk of type 2 diabetes in population s of European descent ; however , data from high-risk Asian population s are lacking as are data on tea intake in general . OBJECTIVE We investigated the prospect i ve associations between intakes of coffee , black tea , and green tea with the risk of type 2 diabetes in Singaporean Chinese men and women . DESIGN We analyzed data from 36 908 female and male participants in the Singapore Chinese Health Study aged 45 - 74 y in 1993 - 1998 who had multiple diet and lifestyle measures assessed and then were followed up between 1999 and 2004 . We used Cox regression models to investigate the association of baseline coffee and tea intakes with incident type 2 diabetes during follow-up , with adjustment for a number of possible confounding or mediating variables . RESULTS In multivariate models participants reporting > or = 4 cups of coffee/d had a 30 % reduction in risk of diabetes [ relative risk ( RR ) : 0.70 ; 95 % CI : 0.53 , 0.93 ] compared with participants who reported nondaily consumption . Participants reporting > or = 1 cup of black tea/d had a suggestive 14 % reduction in risk of diabetes ( RR : 0.86 ; 95 % CI : 0.74 , 1.00 ) compared with participants who reported 0 cups/d , and we observed no association with green tea . CONCLUSION Regular consumption of coffee and potentially black tea , but not green tea , is associated with lower risk of type 2 diabetes in Asian men and women in Singapore Context Caffeine intake from coffee has been associated with a lower incidence of diabetes . Research ers have not studied the relationship of green tea , a popular beverage in Japan , where the incidence of diabetes is increasing rapidly . Contributions The authors estimated the intake of caffeine-containing beverages in a community-based survey in Japan and measured the 5-year incidence of diabetes . Greater intake of green tea or coffee was associated with a reduced incidence of diabetes . The effect of green tea was largely observed in women , was dose-related , and reflected caffeine intake . Implication s Higher intake of caffeine , whether from coffee or green tea , is associated with a lower incidence of diabetes . The Editors The prevalence of type 2 diabetes has increased worldwide , particularly in Asian countries where it was previously low ( 1 ) . In Japan , population -based studies have shown a 2-fold increase in the prevalence of diabetes during the past 2 decades , from 5 % to 10 % to 10 % to 15 % ( 2 ) . Several cohort studies done in Europe and in the United States reported an association between coffee consumption , a major source of caffeine , and reduced risk for diabetes ( 3 - 7 ) . Although these studies did not show any association between consumption of black tea and the risk for diabetes , they did not examine the effect of green or oolong teas , major sources of caffeine in Asian countries . Consumption of green tea is common in Japan ; 80 % of the population drinks green tea , and the average consumption per capita is 2 cups per day ( 8) . We wanted to determine whether there is a relationship between consumption of green tea and the risk for type 2 diabetes and , if so , whether caffeine fully accounts for this relationship . To examine these questions , we analyzed data from a large cohort study of 19487 middle-aged men and women in 25 communities across Japan . We also examined the effect of age , sex , body mass index ( BMI ) , family history , smoking status , alcohol use , magnesium intake , and physical activity on the association between this mode of caffeine consumption and risk for diabetes . Methods The Japan Collaborative Cohort Study for Evaluation of Cancer Risk ( JACC Study ) started between 1988 and 1990 . A total of 110792 individuals ( 46465 men and 64327 women ) who were 40 to 79 years of age and living in 45 communities across Japan participated in municipal health screening examinations and completed self-administered question naires regarding lifestyle and medical history of cardiovascular disease and cancer ( 9 ) . Informed consent was obtained before the completion of the question naire . Participants from 25 of the 45 communities completed 5-year follow-up surveys . Among 35690 participants ( 15177 men and 20513 women ) who were 40 to 65 years of age at baseline without a history of type 2 diabetes , stroke , coronary heart disease , or cancer , 17413 individuals ( 49 % ; 6727 men and 10686 women ) completed the 5-year follow-up question naire and provided valid responses on tea or coffee consumption and history of type 2 diabetes . The data from these 17413 individuals were used for the analyses . The mean age of the nonrespondents was 1 year younger for men ( 52.3 vs. 53.3 years of age ) and did not differ for women ( 53.1 vs. 53.0 years of age ) compared with the respondents . The mean BMI and the prevalence of a BMI of 25.0 kg/m2 or greater did not differ between the respondents and nonrespondents . Mean BMI was 22.7 kg/m2 versus 22.8 kg/m2 for men and 22.8 kg/m2 versus 22.9 kg/m2 for women , respectively ; the prevalence of overweight was 18 % versus 19 % for men and 21 % versus 22 % for women , respectively . The ethical committees at Nagoya University and the University of Tsukuba approved the study . Assessment of Consumption of Tea and Coffee and Caffeine Intake At baseline , consumption of tea and coffee  was assessed by using a self-administered dietary question naire . Participants were asked to state their average consumption of green tea , black tea , oolong tea , and coffee during the previous year . They could select any of 4 frequency responses : less than once a week , about 1 to 2 times a week , about 3 to 4 times a week , and almost every day . Participants who selected the response of almost every day were also asked to state their average consumption of these beverages in number of cups per day . We classified the categories of consumption as less than 1 cup per week , 1 to 6 cups per week , 1 to 2 cups per day , 3 to 5 cups per day , and 6 or more cups per day . The highest 2 or 3 consumption categories were combined for coffee , black tea , and oolong tea because of the small number of participants in these categories . The consumption of decaffeinated coffee or tea  was not recorded because these products were not commercially available in Japan in the early 1990s . The total intake of caffeine was calculated by adding the caffeine content from each specific beverage ( 1 cup for coffee or tea ) and multiplying it by the participant 's weight proportional to the frequency of caffeine use . We estimated the size of the cup for each beverage from a validation study ( 10 ) and the caffeine content per 100 mL of each beverage from the Japan Food Tables ( 11 ) . The estimated caffeine content was 153 mg per cup ( 170 mL ) of coffee , 30 mg per cup ( 200 mL ) of green tea , 51 mg per cup ( 170 mL ) of black tea , and 38 mg per cup ( 190 mL ) of oolong tea . The mean caffeine intake was 229 mg/d for men and 215 mg/d for women .  Relative proportions of caffeine intake by beverage were 46 % from green tea , 44 % to 47 % from coffee , 3 % from black tea , and 4 % to 5 % from oolong tea . For reproducibility , the Spearman correlation coefficients between the 2 question naires , administered 1 year apart for 85 participants ( 8 men and 77 women ) , were 0.79 for green tea , 0.87 for coffee , 0.77 for black tea , and 0.56 for oolong tea ( 10 ) . The validity of the data was confirmed for the 85 participants by comparing the data from the question naire with those from four 3-day dietary records collected approximately 3 to 4 months apart ( 10 ) . The mean frequency of consumption of green tea  was 25.4 cups per week according to the question naire and 30.1 cups per week according to four 1-week dietary records ( Spearman correlation coefficient , 0.47 ) . The respective mean frequencies were 8.0 cups and 7.1 cups per week with a correlation coefficient of 0.79 for coffee , 1.4 cups and 1.6 cups per week with a correlation coefficient of 0.70 for black tea , and 1.8 cups and 1.2 cups per week with a correlation coefficient of 0. 
    Output:
    
agent
The consumption of green tea did not decrease the levels of fasting plasma glucose , fasting serum insulin , OGTT-2 h glucose , haemoglobin A₁c and HOMA(IR ) in population s at risk of T2DM .
***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 Green tea is one of the most popular beverages worldwide . This review summarizes the beneficial effects of green tea on cancer prevention . Methods Electronic data bases , including PubMed ( 1966–2008 ) , the Cochrane Library ( Issue 1 , 2008 ) and Chinese Biomedical Data base ( 1978–2008 ) with supplement of relevant websites , were search ed . There was no language restriction . The search es ended at March 2008 . We included r and omized and non-r and omized clinical trials , epidemiological studies ( cohort and case-control ) and a meta- analysis . We excluded case series , case reports , in vitro and animal studies . Outcomes were measured with estimation of relative risk , hazard or odd ratios , with 95 % confidence interval . Results Forty-three epidemiological studies , four r and omized trials and one meta- analysis were identified . The overall quality of these studies was evaluated as good or moderate . While some evidence suggests that green tea has beneficial effects on gastrointestinal cancers , the findings are not consistent . Conclusion Green tea may have beneficial effects on cancer prevention . Further studies such as large and long term cohort studies and clinical trials are warranted BACKGROUND Green tea is one of the most popular beverages in the world . It is believed to have beneficial effects in the prevention and treatment of many diseases , one of which is type 2 diabetes . The aim of the study is to examine the effect of a decaffeinated green tea extract ( GTE ) providing a daily dose of 856 mg of epigallocatechin gallate ( EGCG ) on obese individuals with type 2 diabetes . MATERIAL S AND METHODS The clinical trial was a r and omized , double-blind , placebo-controlled clinical trial conducted from December 2007 through November 2008 . The subjects were r and omly assigned to either receive 1,500 mg of a decaffeinated GTE or placebo daily for 16 weeks . Sixty-eight of 80 subjects , ages 20 - 65 years with BMI > 25 kg/m2 and type 2 diabetes for more than one year , completed this study .  Homeostasis model assessment for insulin resistance ( HOMA-IR ) was used as the major outcome measurement . At baseline and after 16 weeks of treatment , anthropometric measurements , fasting glucose , hemoglobin A1C percent ( HbA1C ) , hormone peptides , and plasma lipoproteins were measured from both groups . RESULTS No statistically significant differences were detected between the decaffeinated GTE and placebo groups in any measured variable . A statistically significant within-group 0.4-percent reduction in HbA1C ( from 8.4 to 8.0 % ) was observed after GTE treatment compared to baseline . Within-group comparison also revealed that the GTE group had significant reductions in waist circumference ( WC ) , HOMA-IR index , and insulin level , and a significant increase in the level of ghrelin . Within-group comparison of those in the placebo group showed a significant increase in the level of ghrelin . CONCLUSIONS This study found no statistical difference in any measured variable between the decaffeinated GTE and placebo groups ; however , there were some statistically significant within-group changes detected . More research is required to determine whether a decaffeinated GTE st and ardized for EGCG content will provide any clinical benefits in obese individuals with type 2 diabetes . Clinical Trial Registration NO : NCT00567905 Objectives : The development of obesity is characterized by an increase in adipose tissue mass and by concomitant and profound changes in almost all organ functions leading to diseases such as hypertension , diabetes mellitus and coronary heart disease . Recent data from human studies indicate that the consumption of green tea and green tea extracts may help reduce body weight , mainly body fat , by increasing postpr and ial thermogenesis and fat oxidation . However , human studies investigating the metabolic effects of the most predominant tea catechin , EGCG , alone are absent . Methods : In a r and omized double blind , placebo-controlled , cross-over pilot study , six overweight men were given 300 mg EGCG/d for 2d . Fasting and postpr and ial changes in energy expenditure ( EE ) and substrate oxidation were assessed . Results : Resting EE did not differ significantly between EGCG and placebo treatments , although during the first postpr and ial monitoring phase , respiratory quotient ( RQ ) values were significantly lower with EGCG compared to the placebo . Conclusions : These findings suggest that EGCG alone has the potential to increase fat oxidation in men and may thereby contribute to the anti-obesity effects of green tea . However , more studies with a greater sample size and a broader range of age and BMI are needed to define the optimum dose BACKGROUND Increasing coffee intake was inversely associated with risk of type 2 diabetes in population s of European descent ; however , data from high-risk Asian population s are lacking as are data on tea intake in general . OBJECTIVE We investigated the prospect i ve associations between intakes of coffee , black tea , and green tea with the risk of type 2 diabetes in Singaporean Chinese men and women . DESIGN We analyzed data from 36 908 female and male participants in the Singapore Chinese Health Study aged 45 - 74 y in 1993 - 1998 who had multiple diet and lifestyle measures assessed and then were followed up between 1999 and 2004 . We used Cox regression models to investigate the association of baseline coffee and tea intakes with incident type 2 diabetes during follow-up , with adjustment for a number of possible confounding or mediating variables . RESULTS In multivariate models participants reporting > or = 4 cups of coffee/d had a 30 % reduction in risk of diabetes [ relative risk ( RR ) : 0.70 ; 95 % CI : 0.53 , 0.93 ] compared with participants who reported nondaily consumption . Participants reporting > or = 1 cup of black tea/d had a suggestive 14 % reduction in risk of diabetes ( RR : 0.86 ; 95 % CI : 0.74 , 1.00 ) compared with participants who reported 0 cups/d , and we observed no association with green tea . CONCLUSION Regular consumption of coffee and potentially black tea , but not green tea , is associated with lower risk of type 2 diabetes in Asian men and women in Singapore Context Caffeine intake from coffee has been associated with a lower incidence of diabetes . Research ers have not studied the relationship of green tea , a popular beverage in Japan , where the incidence of diabetes is increasing rapidly . Contributions The authors estimated the intake of caffeine-containing beverages in a community-based survey in Japan and measured the 5-year incidence of diabetes . Greater intake of green tea or coffee was associated with a reduced incidence of diabetes . The effect of green tea was largely observed in women , was dose-related , and reflected caffeine intake . Implication s Higher intake of caffeine , whether from coffee or green tea , is associated with a lower incidence of diabetes . The Editors The prevalence of type 2 diabetes has increased worldwide , particularly in Asian countries where it was previously low ( 1 ) . In Japan , population -based studies have shown a 2-fold increase in the prevalence of diabetes during the past 2 decades , from 5 % to 10 % to 10 % to 15 % ( 2 ) . Several cohort studies done in Europe and in the United States reported an association between coffee consumption , a major source of caffeine , and reduced risk for diabetes ( 3 - 7 ) . Although these studies did not show any association between consumption of black tea and the risk for diabetes , they did not examine the effect of green or oolong teas , major sources of caffeine in Asian countries . Consumption of green tea is common in Japan ; 80 % of the population drinks green tea , and the average consumption per capita is 2 cups per day ( 8) . We wanted to determine whether there is a relationship between consumption of green tea and the risk for type 2 diabetes and , if so , whether caffeine fully accounts for this relationship . To examine these questions , we analyzed data from a large cohort study of 19487 middle-aged men and women in 25 communities across Japan . We also examined the effect of age , sex , body mass index ( BMI ) , family history , smoking status , alcohol use , magnesium intake , and physical activity on the association between this mode of caffeine consumption and risk for diabetes . Methods The Japan Collaborative Cohort Study for Evaluation of Cancer Risk ( JACC Study ) started between 1988 and 1990 . A total of 110792 individuals ( 46465 men and 64327 women ) who were 40 to 79 years of age and living in 45 communities across Japan participated in municipal health screening examinations and completed self-administered question naires regarding lifestyle and medical history of cardiovascular disease and cancer ( 9 ) . Informed consent was obtained before the completion of the question naire . Participants from 25 of the 45 communities completed 5-year follow-up surveys . Among 35690 participants ( 15177 men and 20513 women ) who were 40 to 65 years of age at baseline without a history of type 2 diabetes , stroke , coronary heart disease , or cancer , 17413 individuals ( 49 % ; 6727 men and 10686 women ) completed the 5-year follow-up question naire and provided valid responses on tea or coffee consumption and history of type 2 diabetes . The data from these 17413 individuals were used for the analyses . The mean age of the nonrespondents was 1 year younger for men ( 52.3 vs. 53.3 years of age ) and did not differ for women ( 53.1 vs. 53.0 years of age ) compared with the respondents . The mean BMI and the prevalence of a BMI of 25.0 kg/m2 or greater did not differ between the respondents and nonrespondents . Mean BMI was 22.7 kg/m2 versus 22.8 kg/m2 for men and 22.8 kg/m2 versus 22.9 kg/m2 for women , respectively ; the prevalence of overweight was 18 % versus 19 % for men and 21 % versus 22 % for women , respectively . The ethical committees at Nagoya University and the University of Tsukuba approved the study . Assessment of Consumption of Tea and Coffee and Caffeine Intake At baseline , consumption of tea and coffee  was assessed by using a self-administered dietary question naire . Participants were asked to state their average consumption of green tea , black tea , oolong tea , and coffee during the previous year . They could select any of 4 frequency responses : less than once a week , about 1 to 2 times a week , about 3 to 4 times a week , and almost every day . Participants who selected the response of almost every day were also asked to state their average consumption of these beverages in number of cups per day . We classified the categories of consumption as less than 1 cup per week , 1 to 6 cups per week , 1 to 2 cups per day , 3 to 5 cups per day , and 6 or more cups per day . The highest 2 or 3 consumption categories were combined for coffee , black tea , and oolong tea because of the small number of participants in these categories . The consumption of decaffeinated coffee or tea  was not recorded because these products were not commercially available in Japan in the early 1990s . The total intake of caffeine was calculated by adding the caffeine content from each specific beverage ( 1 cup for coffee or tea ) and multiplying it by the participant 's weight proportional to the frequency of caffeine use . We estimated the size of the cup for each beverage from a validation study ( 10 ) and the caffeine content per 100 mL of each beverage from the Japan Food Tables ( 11 ) . The estimated caffeine content was 153 mg per cup ( 170 mL ) of coffee , 30 mg per cup ( 200 mL ) of green tea , 51 mg per cup ( 170 mL ) of black tea , and 38 mg per cup ( 190 mL ) of oolong tea . The mean caffeine intake was 229 mg/d for men and 215 mg/d for women .  Relative proportions of caffeine intake by beverage were 46 % from green tea , 44 % to 47 % from coffee , 3 % from black tea , and 4 % to 5 % from oolong tea . For reproducibility , the Spearman correlation coefficients between the 2 question naires , administered 1 year apart for 85 participants ( 8 men and 77 women ) , were 0.79 for green tea , 0.87 for coffee , 0.77 for black tea , and 0.56 for oolong tea ( 10 ) . The validity of the data was confirmed for the 85 participants by comparing the data from the question naire with those from four 3-day dietary records collected approximately 3 to 4 months apart ( 10 ) . The mean frequency of consumption of green tea  was 25.4 cups per week according to the question naire and 30.1 cups per week according to four 1-week dietary records ( Spearman correlation coefficient , 0.47 ) . The respective mean frequencies were 8.0 cups and 7.1 cups per week with a correlation coefficient of 0.79 for coffee , 1.4 cups and 1.6 cups per week with a correlation coefficient of 0.70 for black tea , and 1.8 cups and 1.2 cups per week with a correlation coefficient of 0. 
    Output:
    