Background and Purpose: Although it has been hypothesized that a high intake of dietary calcium may reduce the risk of cardiovascular disease (CVD), no prospective studies have been conducted to examine the specific association between calcium intake and incidence of stroke or coronary heart disease among Japanese with a low average calcium intake.
Methods: To investigate the association between calcium intake and risk of CVD, a total of 41,526 Japanese men and women age 40 to 59 years without a history of CVD or cancer and who had completed a food consumption frequency questionnaire were enrolled in this study.
The subjects were followed up from 1990 to 1992 to 2003, and after 533,692 person-years of follow-up, 1,321 incident cases of stroke (664 ischemic, 425 intraparenchymal hemorrhage, and 217 subarachnoid hemorrhage) and 322 of coronary heart disease were documented.
Total calcium intake showed an inverse association with the risk of total stroke; the multivariable hazard ratio and 95% CIs for the highest versus the lowest quintile were 0.70 (95% CI, 0.56 to 0.88; P for trend=0.02). [Equal levels of stroke risk would be 1.00. Thus the highest calcium intake group had 30% less stroke risk than the lowest intake group.]
Dairy calcium intake was inversely associated with risks of total and ischemic stroke with respective multivariable hazard ratios (95% CIs) of 0.69 (0.56 to 0.85; P for trend=0.007) and 0.69 (0.52 to 0.93; P for trend=0.05).
Dietary calcium intake was not significantly associated with risk of coronary heart disease.
Conclusions: Dietary calcium intake, especially calcium from dairy products, was found to be associated with a reduced incidence of stroke among middle-aged Japanese.
Source: Stroke, July 17, 2008. PMID: 18635855, by Umesawa M, Iso H, Ishihara J, Saito I, Kokubo Y, Inoue M, Tsugane S; for the JPHC Study Group. Department of Public Health Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba; Public Health Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Osaka; Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo; Department of Public Health, University of Ehime, Ehime; Department of Preventive Cardiology, National Cardiovascular Center, Osaka, Japan. [E-mail: email@example.com or firstname.lastname@example.org]