***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: To determine the impact of dietary patterns on the control of hypertension we studied the subgroup of 133 participants with systolic blood pressure ( BP ) of 140 to 159 mm Hg and /or diastolic BP of 90 to 95 mm Hg enrolled in the Dietary Approaches to Stop Hypertension ( DASH ) study . Participants were fed a control diet for a 3-week period and were then r and omized to receive for 8 weeks either the control diet ; a diet rich in fruits and vegetables , but otherwise similar to control ; or a combination diet rich in fruits , vegetables , and low-fat dairy products , including whole grains , fish , poultry , and nuts , and reduced in fats , red meats , sweets , and sugar-containing beverages .  Sodium intake and body weight were held constant throughout the study . The combination diet significantly reduced systolic BP ( -11.4 mm Hg , P < .001 ) and diastolic BP ( -5.5 mm Hg , P < .001 ) . The fruits- and -vegetables diet also significantly reduced systolic BP ( -7.2 mm Hg , P < .001 ) and diastolic BP ( -2.8 mm Hg , P = .013 ) . The combination diet produced significantly greater BP effects ( P < .05 ) than the fruits- and -vegetables diet .  Blood pressure changes were evident within 2 weeks of starting the intervention feeding . After the 8-week intervention period , 70 % of participants eating the combination diet had a normal BP ( systolic BP < 140 and diastolic BP < 90 mm Hg ) compared with 45 % on the fruits- and -vegetables diet and 23 % on the control diet . In patients with hypertension , the DASH combination diet effectively lowers BP and may be useful in achieving control of Stage 1 hypertension BACKGROUND It is known that obesity , sodium intake , and alcohol consumption factors influence blood pressure . In this clinical trial , Dietary Approaches to Stop Hypertension , we assessed the effects of dietary patterns on blood pressure . METHODS We enrolled 459 adults with systolic blood pressures of less than 160 mm Hg and diastolic blood pressures of 80 to 95 mm Hg . For three weeks , the subjects were fed a control diet that was low in fruits , vegetables , and dairy products , with a fat content typical of the average diet in the United States . They were then r and omly assigned to receive for eight weeks the control diet , a diet rich in fruits and vegetables , or a " combination " diet rich in fruits , vegetables , and low-fat dairy products and with reduced saturated and total fat . Sodium intake and body weight were maintained at constant levels . RESULTS At base line , the mean ( + /-SD ) systolic and diastolic blood pressures were 131.3+/-10.8 mm Hg and 84.7+/-4.7 mm Hg , respectively . The combination diet reduced systolic and diastolic blood pressure by 5.5 and 3.0 mm Hg more , respectively , than the control diet ( P<0.001 for each ) ; the fruits- and -vegetables diet reduced systolic blood pressure by 2.8 mm Hg more ( P<0.001 ) and diastolic blood pressure by 1.1 mm Hg more than the control diet ( P=0.07 ) . Among the 133 subjects with hypertension ( systolic pressure , > or = 140 mm Hg ; diastolic pressure , > or = 90 mm Hg ; or both ) , the combination diet reduced systolic and diastolic blood pressure by 11.4 and 5.5 mm Hg more , respectively , than the control diet ( P<0.001 for each ) ; among the 326 subjects without hypertension , the corresponding reductions were 3.5 mm Hg ( P<0.001 ) and 2.1 mm Hg ( P=0.003 ) . CONCLUSIONS A diet rich in fruits , vegetables , and low-fat dairy foods and with reduced saturated and total fat can substantially lower blood pressure . This diet offers an additional nutritional approach to preventing and treating hypertension Background The role of water hardness as a risk factor for cardiovascular disease has been widely investigated and evaluated as regards regional differences in cardiovascular disease . This study was performed to evaluate the relation between calcium and magnesium in drinking water and diet and risk factors for cardiovascular disease in individuals living in hard and soft water areas with considerable differences in cardiovascular mortality . Methods A r and om sample of 207 individuals living in two municipalities characterised by differences in cardiovascular mortality and water hardness was invited for an examination including a question naire about health , social and living conditions and diet . Intake of magnesium and calcium was calculated from the diet question naire with special consideration to the use of local water . Household water sample s were delivered by each individual and were analysed for magnesium and calcium . Results In the total sample , there were positive correlations between the calcium content in household water and systolic blood pressure ( SBP ) and negative correlations with s-cholesterol and s-LDL-cholesterol . No correlation was seen with magnesium content in household water to any of the risk factors . Calcium content in diet showed no correlation to cardiovascular risk factors . Magnesium in diet was positively correlated to diastolic blood pressure ( DBP ) . In regression analyses controlled for age and sex 18.5 % of the variation in SBP was explained by the variation in BMI , HbA1c and calcium content in water . Some 27.9 % of the variation in s-cholesterol could be explained by the variation in s-triglycerides ( TG ) , and calcium content in water . Conclusions This study of individuals living in soft and hard water areas showed significant correlations between the content of calcium in water and major cardiovascular risk factors . This was not found for magnesium in water or calcium or magnesium in diet . Regression analyses indicated that calcium content in water could be a factor in the complexity of relationships and importance of cardiovascular risk factors . From these results it is not possible to conclude any definite causal relation and further research is needed We investigated the importance of magnesium and calcium in drinking water in relation to morbidity and mortality from acute myocardial infa rct ion . Cases were men and women 50 - 74 years of age living in 18 Swedish municipalities who had suffered an acute myocardial infa rct ion some time between October 1 , 1994 , and June 30 , 1996 . Controls were r and omly selected from the same study base . We interviewed the surviving cases ( N = 823 ) and controls ( N = 853 ) , focusing on risk factors for acute myocardial infa rct ion . We collected individual data on drinking water levels of magnesium and calcium . We classified subjects by quartile of water magnesium or calcium levels . The total number of cases was similar in the four quartiles . The risk of death was 7.6 % ( 95 % confidence interval = 2.1 - 13.1 ) lower in the quartile with high magnesium levels ( > or = 8.3 mg/liter ) . The odds ratio for death from acute myocardial infa rct ion in relation to water magnesium was 0.64 ( 95 % confidence interval = 0.42 - 0.97 ) for the highest quartile relative to the three lower ones . Multivariate analyses showed that other risk factors were not important confounders . For calcium , this study was inconclusive . The data suggest that magnesium in drinking water is associated with lower mortality from acute myocardial infa rct ion , but not with the total incidence Nutritional sodium , potassium and calcium are considered to be important regulators of blood pressure ( BP ) . The present study evaluates the effects of combined low-sodium ( LS ) , high-potassium ( HK ) , high-calcium ( HCa ) diet on BP in patients with mild essential hypertension . Thirty-six patients ( 26 M , 10 F ) , 24–67 years of age ( mean 46 ± 8) , participated in the study . Patients were divided into three groups and given a diet consisting of three 1-month segments , which they followed in different order . Group 1 ( n = 11 ) received LS diet followed by the addition of HCa and then HK . The order in Group 2 ( n = 12 ) was HK-LS-HCa ; and in Group 3 ( n = 13 ) it was HCa-HK-LS . The third month of the study all patients were eating a combined LS , HK and HCa diet  . Urinary electrolytes were measured to confirm compliance with the diets . After 1 month of the LS diet urinary sodium excretion decreased significantly by 25 mmols/day ( 95 % CI , 1–48 mmols/day ) ; ( P < 0.05 ) . eighteen patients did not comply with the diet . systolic bp ( sbp ) only slightly decreased , from 142 mm hg ( 95 % ci , 137–146 mm hg ) to 138 mm hg ( 95 % ci , 133–142 mm hg ) ; ( P = 0.11 ) . The change in SBP was related to the change in urinary sodium excretion ( R = 0.46 ; P = 0.006 ) . After 1 month of the HK diet , urinary potassium excretion increased by only 5 mmols/day ( P = NS ) . BP was unaffected by HK and HCa diet . At the end of the study , urinary sodium excretion decreased from 183 mmols/day ( 95 % CI , 155–211 mmols/day ) to 148 mmols/day ( 95 % CI , 131–165 mmols/day ) ; ( P < 0.05 ) , urinary potassium excretion slightly increased from 75 mmols/day ( 95 % ci , 68–82 mmols/day ) to 85 mmols/day ( 95 % ci , 76–94 mmols/day ) ; ( P = 0.09 ) , and urinary calcium excretion remained unchanged . BP did not decrease . It is concluded that only the LS diet may be advantageous in patients with mild essential hypertension Background It has been previously suggested that hard drinking water in general , and in particular high calcium and magnesium intake from drinking water , protect against cardiovascular disease . Design Prospect i ve study of men from 24 British towns , with widely differing levels of hardness in drinking water . Methods A total of 7735 men aged 40–59 years were recruited during 1978–1980 . Estimates of town-level water hardness were available and tap water sample s , taken from 947 participants who also answered a question naire about water consumption , were used to calculate individual calcium and magnesium intakes . Men were followed for incident of major coronary heart disease ( CHD ) and stroke , and CHD mortality for 25 years . Results Water hardness varied from 0.27 to 5.28 mmol/l in the 24 towns . A weak inverse association was found between water hardness and incidence of cardiovascular disease ( CVD ) [ hazard ratio ( HR ) , 0.96 per two-fold increase , 95 % confidence interval ( CI ) , 0.91–1.01 , P = 0.08 after adjustment for age and seven established coronary risk factors ] . No association was observed with CHD incidence ( adjusted HR , 0.99 , 95 % CI , 0.94–1.04 , P = 0.62 ) or mortality ( adjusted HR , 0.96 , 95 % CI , 0.90–1.02 , P = 0.18 ) . Individual magnesium intake showed a positive , rather than an inverse , association with CHD incidence ( adjusted HR , 1.10 per two-fold increase , 95 % CI , 1.01–1.20 , P = 0.045 ) ; individual calcium intake was unrelated to CHD or CVD end points . Conclusions This study suggests that neither high water hardness , nor high calcium or magnesium intake appreciably protect against CHD or CVD . Initiatives to add calcium and magnesium to desalinated water can not be justified by these findings Cardiovascular disease ( CVD ) has been the first cause of mortality in the population of Puy de Dôme ( PDD ) ( France ) between 1988 and 1992 . The mortality rates are significantly higher than those observed in the whole population of France ( for the female population , 354.8 versus 327.3 per 100,000 persons/year and for the male population , 335.7 versus 287.9 per 100,000 persons/year ) . Moreover , an ecological study , which used the St and ardized Mortality Ratios ( SMR ) and performed at the canton level , has allowed a special variation of mortality from CVD in PDD to be described . A decreased gradient of mortality ( especially , " Ischemic Heart diseases " [ ICM-9 , codes 410 - 414 ] and " Cerebro-vascular Diseases " [ ICM-9 , codes 430 - 438 ] ) has been observed from the periphery ( rural area ) to the middle ( urban area ) of PDD . Moreover , a statistically significant negative relationship has been observed between the hardness of the drinking water supplies 
    Output:
    
Hard water consumption seems to be protective against CVD .