Dietary magnesium intake and risk of hypertension in a Mexican adult population: A cohort study

Abstract

Background: Hypertension is associated with increased risk of heart disease, stroke, kidney failure, premature mortality, and disability. This rising prevalence of hypertension has been linked to insufficient dietary magnesium intake. However, epidemiological evidence supporting this relationship is inconsistent. To investigate whether magnesium intake affects blood pressure, we examined the association between dietary magnesium intake and the incidence of hypertension in apparently healthy Mexican adults participating in the Health Workers Cohort Study. Methods: A total of 1,378 subjects (77.4% women and 22.6% men), participating in the Health Workers Cohort Study, free of hypertension at baseline (systolic blood pressure <140 mmHg or/and diastolic blood pressure <90 mmHg), were prospectively studied. Magnesium intake was evaluated using a semi-quantitative food frequency questionnaire. The longitudinal relationships between dietary magnesium intake and the incidence of hypertension were analyzed with generalized estimation equations. Results: During a median follow-up of 7 years, 16.4% of women and 31.9% of men developed incident hypertension. After adjustment for age and sex, we found a trend of decreasing diastolic blood pressure with rising magnesium intake, by tertiles (the coefficients were −0.75 mmHg [95% confidence interval (CI): −1.77, 0.27], −1.27 mmHg (95% CI: −2.73, −0.02; P for trend = 0.01). This inverse association was attenuated after further adjustment for known risk factors. In the fully adjusted model, magnesium intake was inversely associated, although not significantly, with the risk of developing hypertension; subjects in the highest tertile of magnesium intake had a decreased risk for hypertension (odds ratio 0.83, 95% CI: 0.49–1.39, P for trend = 0.48). Conclusions: These results do not support the hypothesis that magnesium intake reduces the development of hypertension, although a modest inverse association between magnesium consumption and lower blood pressure cannot be ruled out