Objective: Dietary magnesium intake has been associated with a reduced risk of type 2 diabetes in western populations, but the evidence is limited in Asian populations.
Methods: We assessed the relationship between dietary magnesium intake and risk of diabetes in a cohort of 17,592 individuals (6480 men and 11,112 women) aged 40-65, free of a history of diabetes or other chronic disease at the time of the baseline lifestyle survey, who completed a 5-year follow-up questionnaire. Dietary magnesium was calculated by using a validated questionnaire, and the incidence of diabetes was defined by self-report of physician diagnosis. Associations between dietary magnesium and diabetes incidence were evaluated using a logistic regression model.
Results: We found 459 self-reported new cases of diabetes (237 men and 222 women) at the 5-year follow-up. Dietary intake of magnesium was inversely associated with age- and body mass index (BMI)-adjusted diabetes incidence in both sexes. In multivariable analysis that adjusted further for cardiovascular risk factors, the association was weakened in both sexes, but the association in total participants remained statistically significant. The odds ratios of diabetes with reference to the lowest quartile of magnesium intake were 0.83 (95% confidence interval [CI], 0.69 to 1.09) for the second quartile, 0.79 (95% CI, 0.59 to 1.07) for the third quartile, and 0.64 (95% CI, 0.44 to 0.94) for the highest quartile of magnesium intake (p for trend = 0.04).
Conclusions: Dietary intake of magnesium was associated with a reduced risk of type 2 diabetes in Japanese populations.