title: Intakes of magnesium, potassium, and calcium and the risk of stroke among men.
abstract: BACKGROUND
  Intakes of magnesium, potassium, and calcium have been inversely associated with the incidence of hypertension, a known risk factor for stroke. However, only a few studies have examined intakes of these cations in relation to risk of stroke.
  
  
  OBJECTIVE
  The aim of this study was to investigate whether high intake of magnesium, potassium, and calcium is associated with reduced stroke risk among men.
  
  
  METHODS
  We prospectively examined the associations between intakes of magnesium, potassium, and calcium from diet and supplements, and the risk of incident stroke among 42 669 men in the Health Professionals Follow-up Study, aged 40 to 75 years and free of diagnosed cardiovascular disease and cancer at baseline in 1986. We calculated the hazard ratio of total, ischemic, and haemorrhagic strokes by quintiles of each cation intake, and of a combined dietary score of all three cations, using multivariate Cox proportional hazard models.
  
  
  RESULTS
  During 24 years of follow-up, 1547 total stroke events were documented. In multivariate analyses, the relative risks and 95% confidence intervals of total stroke for men in the highest vs. lowest quintile were 0·87 (95% confidence interval, 0·74-1·02; P, trend = 0·04) for dietary magnesium, 0·89 (95% confidence interval, 0·76-1·05; P, trend = 0·10) for dietary potassium, and 0·89 (95% confidence interval, 0·75-1·04; P, trend = 0·25) for dietary calcium intake. The relative risk of total stroke for men in the highest vs. lowest quintile was 0·74 (95% confidence interval, 0·59-0·93; P, trend = 0·003) for supplemental magnesium, 0·66 (95% confidence interval, 0·50-0·86; P, trend = 0·002) for supplemental potassium, and 1·01 (95% confidence interval, 0·84-1·20; P, trend = 0·83) for supplemental calcium intake. For total intake (dietary and supplemental), the relative risk of total stroke for men in the highest vs. lowest quintile was 0·83 (95% confidence interval, 0·70-0·99; P, trend = 0·04) for magnesium, 0·88 (95% confidence interval, 0·75-4; P, trend = 6) for potassium, and 3 (95% confidence interval, 79-09; P, trend = 84) for calcium. Men in the highest quintile for a combined dietary score of all three cations had a multivariate relative risk of 0·79 (95% confidence interval, 0·67-0·92; P, trend = 0·008) for total stroke, compared with those in the lowest.
  
  
  CONCLUSIONS
  A diet rich in magnesium, potassium, and calcium may contribute to reduced risk of stroke among men. Because of significant collinearity, the independent contribution of each cation is difficult to define.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.|Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Sally N
authors.initials: SN
authors.lastname: Adebamowo
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.|Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA.|Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.|Department of Global Health and Population, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.|Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Flint
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA, USA.|Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.|Channing Division of Network Medicine, Boston, MA, USA.
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.affiliation: Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Rexrode
mesh_terms: D000328:Adult; D000368:Aged; D002136:Calcium, Dietary / Q000008:administration & dosage*; D006801:Humans; D008137:Longitudinal Studies; D008274:Magnesium / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017419:Potassium, Dietary / Q000008:administration & dosage*; D012307:Risk Factors; D040242:Risk Reduction Behavior; D012720:Severity of Illness Index; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*; D011795:Surveys and Questionnaires
chemical_list: D002136:Calcium, Dietary; D017419:Potassium, Dietary; D008274:Magnesium
keywords: calcium; magnesium; potassium; stroke