***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: Objective : To determine the effects of black tea on postpr and ial plasma glucose and insulin concentrations in healthy humans in response to an oral glucose load . Methods : A four-way r and omised , crossover trial was design ed in which 16 healthy fasted subjects would consume 75 g of glucose in either 250ml of water ( control ) , 250ml of water plus 0.052 g of caffeine ( positive control ) or 250 ml of water plus 1.0 g or 3.0 g of instant black tea .  Blood sample s were collected at fasting and at 30min intervals for 150min from commencement of drink ingestion . Glucose and insulin concentrations were measured using st and ard methodology . The tea was chemically characterised using colorimetric and HPLC methods . Results : Chemical analysis showed that the tea was rich in polyphenolic compounds ( total , 350mg/g ) . Results from only 3 treatment arms are reported because the 3.0 g tea drink caused gastrointestinal symptoms . Plasma glucose concentrations < 60min in response to the drinks were similar , but were significantly reduced at 120min ( P<0.01 ) , following ingestion of the 1.0 g tea drink , relative to the control and caffeine drinks . Tea consumption result ed in elevated insulin concentrations compared with the control and caffeine drinks at 90min ( P<0.01 ) and compared with caffeine drink alone at 150min ( P<0.01 ) . Conclusions : The 1.0 g tea drink reduced the late phase plasma glucose response in healthy humans with a corresponding increase in insulin . This may indicate that the attenuation in postpr and ial glycemia was achieved as a result of an elevated insulin response following stimulation of pancreatic β-cells . This effect may be attributable to the presence of phenolic compounds in the BACKGROUND Rye bread has a beneficial effect on the postpr and ial insulin response in healthy subjects . The role of rye fiber in insulin and glucose metabolism is not known . OBJECTIVE The aim of the study was to determine the effect of the content of rye fiber in rye breads on postpr and ial insulin and glucose responses . DESIGN Nineteen healthy postmenopausal women aged 61 + /- 1 y , with a body mass index ( in kg/m(2 ) ) of 26.0 + /- 0.6 , and with normal glucose tolerance participated in the study . The test products were refined wheat bread ( control ) , endosperm rye bread , traditional rye bread , and high-fiber rye bread ; each bread provided 50 g available carbohydrate and was served with breakfast .  Plasma glucose , insulin , glucose-dependent insulinotropic polypeptide , glucagon-like peptide 1 , and serum C-peptide were measured in fasting and 8 postpr and ial blood sample s. In vitro starch hydrolysis and the microscopic structure of the breads were also determined . RESULTS Postpr and ial insulin , glucose-dependent insulinotropic polypeptide , and C-peptide responses to the rye breads were significantly lower than the response to the control ; no significant differences in insulin and C-peptide responses to the rye breads were found . Glucose and glucagon-like peptide 1 responses to the rye breads were not significantly different from those to the control , except at 150 and 180 min . In vitro starch hydrolysis was slower in all rye breads than in the control , and the structure of continuous matrix and starch granules differed between the rye and control breads . CONCLUSION Total fiber content does not explain the lower postpr and ial insulin response to rye bread than to wheat bread , but structural differences between rye and wheat breads might BACKGROUND Accumulating evidence suggests that certain dietary polyphenols have biological effects in the small intestine that alter the pattern of glucose uptake . Their effects , however , on glucose tolerance in humans are unknown . OBJECTIVE The objective was to investigate whether chlorogenic acids in coffee modulate glucose uptake and gastrointestinal hormone and insulin secretion in humans . DESIGN In a 3-way , r and omized , crossover study , 9 healthy fasted volunteers consumed 25 g glucose in either 400 mL water ( control ) or 400 mL caffeinated or decaffeinated coffee ( equivalent to 2.5 mmol chlorogenic acid/L ) . Blood sample s were taken frequently over the following 3 h. RESULTS Glucose and insulin concentrations tended to be higher in the first 30 min after caffeinated coffee consumption than after consumption of decaffeinated coffee or the control ( P < 0.05 for total and incremental area under the curve for glucose and insulin ) . Glucose-dependent insulinotropic polypeptide secretion decreased throughout the experimental period ( P < 0.005 ) , and glucagon-like peptide 1 secretion increased 0 - 120 min postpr and ially ( P < 0.01 ) after decaffeinated coffee consumption compared with the control . Glucose and insulin profiles were consistent with the known metabolic effects of caffeine . However , the gastrointestinal hormone profiles were consistent with delayed intestinal glucose absorption . CONCLUSIONS Differences in plasma glucose , insulin , and gastrointestinal hormone profiles further confirm the potent biological action of caffeine and suggest that chlorogenic acid might have an antagonistic effect on glucose transport . Therefore , a novel function of some dietary phenols in humans may be to attenuate intestinal glucose absorption rates and shift the site of glucose absorption to more distal parts of the intestine Isoflavones have been shown to improve glucose metabolism , but epidemiologic data are limited . We prospect ively investigated the relationship between soy product and isoflavone intake and the risk of developing type 2 diabetes among Japanese adults . Participants were 25,872 men and 33,919 women aged 45 - 75 y , who participated in the second survey of the Japan Public Health Center-Based Prospect i ve Study and had no history of diabetes .  Soy product and isoflavone intakes were ascertained using a 147-item FFQ . Odds ratios of self-reported , physician-diagnosed type 2 diabetes over 5 y were estimated using logistic regression analysis . A total of 1114 new cases of type 2 diabetes were self-reported . Intakes of soy products and isoflavones were not significantly associated with type 2 diabetes in either men or all women . However , among overweight women ( BMI > or = 25 kg/m(2 ) ) , a higher intake of soy products was associated with a lower risk of type 2 diabetes ; multivariable-adjusted odds ratios ( 95 % CI ) for the lowest through highest quintiles of soy product intake were 1.00 ( reference ) , 0.78 ( 0.52 - 1.18 ) , 0.79 ( 0.52 - 1.20 ) , 0.62 ( 0.39 - 0.99 ) , and 0.89 ( 0.55 - 1.44 ) , respectively , and we found a similar risk pattern for daidzein and genistein intakes . Overall , our results suggest that there are no benefits of soy product or isoflavone intake with respect to risk of type 2 diabetes in either men or women . The possible protective associations of soy and isoflavone intakes among overweight women deserves further investigation BACKGROUND Although higher intakes of fruit , berries , and vegetables ( FBV ) have been associated with reduced risk of  type 2 diabetes ( T2D ) in some observational studies , the evidence is limited and inconclusive . OBJECTIVE We assessed the relation of FBV intake and T2D incidence in Finnish men . DESIGN We studied 2332 men from the prospect i ve , population -based Kuopio Ischaemic Heart Disease Risk Factor Study who were aged 42 - 60 y and free of T2D or impaired fasting glucose at baseline in 1984 - 1989 .  Food intake  was assessed with 4-d food recording .  T2D was assessed by using self-administered question naires , a fasting blood glucose measurement , a 2-h oral-glucose-tolerance test , and record linkage to a reimbursement register on diabetes medication expenses . In the Cox proportional hazards model , HRs for T2D were computed for the highest compared with lowest quartiles of FBV intake adjusted for age , examination year , body mass index , waist-to-hip ratio , smoking , education , physical activity , family history of diabetes , and energy and alcohol intakes . RESULTS During the mean follow-up time of 19.3 y , 432 new cases of T2D occurred . For the total FBV intake ( with the exclusion of potatoes and fruit and berry juices ) , the extreme-quartile multivariable-adjusted HR for T2D was 0.76 ( 95 % CI : 0.57 , 1.02 ; P-trend = 0.15 ) . In the analysis for FBV components , berries had a corresponding HR of 0.65 ( 95 % CI : 0.49 , 0.88 ; P-trend = 0.003 ) , whereas no significant associations were shown for fruit , fruit and berry juices , and vegetables . CONCLUSION Fruit and vegetables , particularly berries , may reduce risk of T2D in men OBJECTIVE Cereal fiber intake is linked to reduced risk of type 2 diabetes  in epidemiological observations . The pathogenic background of this phenomenon is unknown . Based on recent findings , we hypothesized that intake of purified insoluble oat fiber may improve whole-body insulin sensitivity . RESEARCH DESIGN AND METHODS A r and omized , controlled , single-blind , cross-over study was performed , and 17 overweight or obese subjects with normal glucose metabolism were analyzed . After consumption of nine macronutrient-matched portions of fiber-enriched bread ( white bread enriched with 31.2 g insoluble fiber/day ) or control ( white bread ) over a time period of 72 h , whole-body insulin sensitivity was assessed by euglycemic-hyperinsulinemic clamp . Energy intake was individually adjusted by providing st and ardized liquid meals . Hydrogen breath tests were performed to control for dietary adherence . RESULTS When analyzing the entire cohort , whole-body glucose disposal was improved after fiber consumption ( M value 6.56 + /- 0.32 vs. 6.07 + /- 0.27 mg . min(-1 ) . kg(-1 ) ; P = 0.043 ) . Thirteen subjects had increased hydrogen breath test concentrations after fiber consumption , indicating probable dietary adherence . Restricting analysis to these subjects , improvements in M value ( 6.85 + /- 0.34 vs. 6.06 + /- 0.32 mg . min(-1 ) . kg(-1 ) ; P = 0.003 ) and insulin sensitivity , expressed as M/I ratio ( M value divided by mean serum insulin at steady state : 3.73 + /- 0.23 vs. 3.21 + /- 0.27 ; P = 0.02 ) , after fiber consumption were more pronounced . Plasma lipids , serum magnesium , ghrelin , and adiponectin concentrations , as well as substrate utilization and body weight , were not significantly changed by fiber intake ( P > 0.15 ) . CONCLUSIONS Increased insoluble dietary fiber intake for 3 days significantly improved whole-body insulin sensitivity . These data suggest a potential mechanism linking cereal fiber intake and reduced risk of type 2 diabetes Resveratrol is a naturally occurring polyphenolic compound . Numerous animal studies have been reported on its wide-ranging beneficial effects in the biological system including diabetes mellitus ( DM ) . We hypothesized , therefore , that oral supplementation of resveratrol would improve the glycemic control and the associated risk factors in patients with type 2 diabetes mellitus ( T2DM ) . The present clinical study was therefore carried out to test the hypothesis . Sixty-two patients with T2DM were enrolled from Government Headquarters Hospital , Ootacamund , India , in a prospect i ve , open-label , r and omized , controlled trial . Patients were r and omized into control and intervention groups . The control group received only oral hypoglycemic agents , whereas the intervention group received resveratrol ( 250 mg/d ) along with their oral hypoglycemic agents for a period of 3 months . Hemoglobin A(1c ) , lipid profile , urea nitrogen , creatinine , and protein were measured at the baseline and at the end of 3 months . The results reveal that supplementation of resveratrol for 3 months significantly improves the mean hemoglobin A(1c ) ( means ± SD , 9.99 ± 1.50 vs 9.65 ± 1.54 ; P < .05 ) , systolic blood pressure ( mean ± SD , 139.71 ± 16.10 vs 127.92 ± 15.3 
    Output:
    
Although glycaemic and insulin responses differed depending on the polyphenol-carbohydrate combination , overall , polyphenol sources were shown to reduce the peak and early-phase glycaemic response and maintain the glycaemic response in the later stages of digestion .
To a lesser extent , polyphenol sources were also shown to reduce peak insulin response and sustain the insulin response , especially when consumed with bread .
This review supports epidemiological data suggesting that polyphenols in foods and beverages may have a beneficial effect on reducing the risk of type 2 diabetes .
However , the extent of this effect is variable depending on the polyphenol and carbohydrate source