***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 AND PURPOSE High intakes of calcium , potassium , and magnesium have been hypothesized to reduce risks of cardiovascular disease , but only a few prospect i ve studies have examined intakes of these cations in relation to risk of stroke . METHODS In 1980 , 85 764 women in the Nurses ' Health Study cohort , aged 34 to 59 years and free of diagnosed cardiovascular disease and cancer , completed dietary question naires  from which we calculated intakes of calcium , potassium , and magnesium . By 1994 , after 1.16 million person-years of follow-up , 690 incident strokes ( 129 subarachnoid hemorrhages , 74 intraparenchymal hemorrhages , 386 ischemic strokes , and 101 strokes of undetermined type ) had been documented . RESULTS Intakes of calcium , potassium , and magnesium were each inversely associated with age- and smoking-adjusted relative risks of ischemic stroke , excluding embolic infa rct ion of nonatherogenic origin ( n=347 ) . Adjustment for other cardiovascular risk factors , including history of hypertension , attenuated these associations , particularly for magnesium intake . In a multivariate analysis , women in the highest quintile of calcium intake had an adjusted relative risk of ischemic stroke of 0.69 ( 95 % CI , 0.50 to 0.95 ; P for trend=0.03 ) compared with those in the lowest quintile ; for potassium intake the corresponding relative risk was 0.72 ( 95 % CI , 0.51 to 1.01 ; P for trend=0.10 ) . Further simultaneous adjustment for calcium and potassium intake suggested an independent association for calcium intake . The association of risk with calcium intake did not appear to be log linear ; the increase in risk was limited to the lowest quintile of intake , and intakes > approximately 600 mg/d did not appear to reduce risk of stroke further . The inverse association with calcium intake was stronger for dairy than for nondairy calcium intake . Intakes of calcium , potassium , and magnesium were not related to risk of other stroke subtypes . CONCLUSIONS Low calcium intake , and perhaps low potassium intake , may contribute to increased risk of ischemic stroke in middle-aged American women . It remains possible that women in the lowest quintile of calcium intake had unknown characteristics that made them susceptible to ischemic stroke Background and Purpose The etiology of ischemic stroke affects prognosis , outcome , and management . Trials of therapies for patients with acute stroke should include measurements of responses as influenced by subtype of ischemic stroke . A system for categorization of subtypes of ischemic stroke mainly based on etiology has been developed for the Trial of Org 10172 in Acute Stroke Treatment ( TOAST ) . Methods A classification of subtypes was prepared using clinical features and the results of ancillary diagnostic studies . “ Possible ” and “ probable ” diagnoses can be made based on the physician 's certainty of diagnosis . The usefulness and interrater agreement of the classification were tested by two neurologists who had not participated in the writing of the criteria . The neurologists independently used the TOAST classification system in their bedside evaluation of 20 patients , first based only on clinical features and then after review ing the results of diagnostic tests . Results The TOAST classification denotes five subtypes of ischemic stroke : 1 ) large-artery atherosclerosis , 2 ) cardioembolism , 3 ) small-vessel occlusion , 4 ) stroke of other determined etiology , and 5 ) stroke of undetermined etiology . Using this rating system , interphysician agreement was very high . The two physicians disagreed in only one patient . They were both able to reach a specific etiologic diagnosis in 11 patients , whereas the cause of stroke was not determined in nine . Conclusions The TOAST stroke subtype classification system is easy to use and has good interobserver agreement . This system should allow investigators to report responses to treatment among important subgroups of patients with ischemic stroke . Clinical trials testing treatments for acute ischemic stroke should include similar methods to diagnose subtypes of stroke 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 This study assessed the hypothesis that greater magnesium intake is associated with reduced risk for cardiovascular disease ( CVD )  , including myocardial infa rct ion ( MI ) and stroke , in a large prospect i ve cohort of women . In 1993 , a semi-quantitative food frequency question naire was used to assess magnesium intake in 39,876 female health professionals aged 39 to 89 years who had no history of CVD or cancer . During a median of 10 years of follow-up , 1,037 incident cases of CVD were identified , including 280 nonfatal MIs and 368 strokes . After adjustment for age and r and omized treatment status , magnesium intake was not significantly associated with risk for incident CVD . Comparing the highest quintile of magnesium intake ( median 433 mg/day ) with the lowest quintile ( median 255 mg/day ) , the relative risks were 0.87 ( 95 % confidence interval [ CI ] 0.72 to 1.05 , p for trend = 0.24 ) for total CVD , 0.88 ( 95 % CI 0.70 to 1.12 , p for trend = 0.34 ) for coronary heart disease ( CHD ) , 1.03 ( 95 % CI 0.72 to 1.49 , p for trend = 0.96 ) for nonfatal MI , 1.11 ( 95 % CI 0.61 to 2.00 , p for trend = 0.95 ) for CVD death , and 0.87 ( 95 % CI 0.64 to 1.18 , p for trend = 0.55 ) for total stroke . Additional adjustment for other CVD risk factors did not material ly change the observed null associations . In conclusion , the results do not support the hypothesis that magnesium intake reduces the development of CHD , although a modest inverse association with stroke can not be ruled out Purpose Observational studies have reported increased colon cancer recurrence and mortality in patients with states of hyperinsulinemia , including type 2 diabetes , obesity , sedentary lifestyle , and high glycemic load diet . Nut intake has been associated with a lower risk of type 2 diabetes , metabolic syndrome , and insulin resistance . However , the effect of nut intake on colon cancer recurrence and survival is not known . Patients and Methods We conducted a prospect i ve , observational study of 826 eligible patients with stage III colon cancer who reported dietary intake on food frequency question naires while enrolled onto a r and omized adjuvant chemotherapy trial .  Using Cox proportional hazards regression , we assessed associations of nut intake with cancer recurrence and mortality . Results After a median follow-up of 6.5 years , compared with patients who abstained from nuts , individuals who consumed two or more servings of nuts per week experienced an adjusted hazard ratio ( HR ) for disease-free survival of 0.58 ( 95 % CI , 0.37 to 0.92 ; Ptrend = .03 ) and an HR for overall survival of 0.43 ( 95 % CI , 0.25 to 0.74 ; Ptrend = .01 ) . In subgroup analysis , the apparent benefit was confined to  tree nut intake ( HR for disease-free survival , 0.54 ; 95 % CI , 0.34 to 0.85 ; Ptrend = .04 ; and HR for overall survival , 0.47 ; 95 % CI , 0.27 to 0.82 ; Ptrend = .04 ) . The association of total nut intake with improved outcomes was maintained across other known or suspected risk factors for cancer recurrence and mortality . Conclusion Diets with a higher consumption of nuts may be associated with a significantly reduced incidence of cancer recurrence and death in patients with stage III colon cancer 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 Microbial modulation of diabetes Short-chain fatty acids ( SCFAs ) are produced by various human gut microbes . SCFAs act as an energy source to the colonic epithelium and are also sensed by host signaling pathways that modulate appetite and inflammation . Deficiency of gut SCFAs is associated with type 2 diabetes . Zhao et al. found that adopting a high-fiber diet promoted the growth of SCFA-producing organisms in diabetic humans . The high-fiber diet induced changes in the entire gut microbe community and correlated with elevated levels of glucagon-like peptide-1 , a decline in acetylated hemoglobin levels , and improved blood-glucose regulation . Science , this issue p. 1151 Increasing dietary fiber intake increases the abundance of short-chain fatty acid – producing gut microbes and relieves diabetes . The gut microbiota benefits humans via short-chain fatty acid ( SCFA ) production from carbohydrate fermentation , and deficiency in SCFA production is associated with type 2 diabetes mellitus ( T2DM ) . We conducted a r and omized clinical study of specifically design ed isoenergetic diets , together with fecal shotgun metagenomics , to show that a select group of SCFA-producing strains was promoted by dietary fibers and that most other potential producers were either diminished or unchanged in patients with T2DM . When the fiber-promoted SCFA producers were present in greater diversity and abundance , participants had better improvement in hemoglobin 
    Output:
    
Subgroup analyses suggested that the risk for total and ischaemic stroke was significantly decreased in females , participants with ≥25 mg/m2 body mass index and those with ≥12-year follow-up ; the reduced risk in Asians was not as notable as that in North American and European population s. CONCLUSIONS Magnesium intake has significantly inverse associations with T2D and total stroke in a dose-dependent manner .