Soft drink intake in relation to incident ischemic heart disease, stroke, and stroke subtypes in Japanese men and women: the Japan Public Health Centre-based study cohort I.

BACKGROUND: Soft drink intake has been associated with obesity and diabetes, but its relation with risk of cardiovascular disease (CVD) is limited.

OBJECTIVE: We examined the association between soft drink intake and risk of CVD in a Japanese population.

DESIGN: This was a prospective study in 39,786 Japanese men and women aged 40-59 y in which soft drink intake was determined by using a self-administered food-frequency questionnaire. Follow-up was from 1990 to 2008. HRs and 95% CIs of incidence were calculated according to categories of soft drink intake.

RESULTS: During 18 y of follow-up, we ascertained 453 incident cases of ischemic heart disease (IHD) and 1922 cases of stroke, including 859 hemorrhagic and 1047 ischemic strokes. Soft drink intake was positively associated with risk of total stroke and more specifically ischemic stroke for women; the multivariable HR (95% CI) in the highest soft drink intake (almost every day) category compared with the lowest intake (never or rarely) category was 1.21 (0.88, 1.68; P-trend = 0.02) for total stroke and 1.83 (1.22, 2.75; P-trend = 0.001) for ischemic stroke. That association did not change significantly after the exclusion of early incident cases within 3-9 y from baseline. A nonsignificant inverse trend for risks of total and ischemic strokes was shown for men, and it was weakened after the exclusion of early incident cases or after the exclusion of participants with baseline comorbidities. Soft drink intake was not associated with risk of IHD or hemorrhagic stroke for either sex.

CONCLUSION: Soft drink intake is associated with higher risk of ischemic stroke for women.