Total fluid and specific beverage intake and mortality due to IHD and stroke in the Netherlands Cohort Study

Chronic mild dehydration has been associated with several diseases, including fatal IHD and stroke. It has been suggested that hydration through total fluid intake (or water) is inversely associated with IHD or stroke mortality. The objective of the present study was to evaluate the relationship between total fluid (and specific beverage) intake and IHD or stroke mortality in the Netherlands Cohort Study (NLCS). In 1986, 120,852 participants aged 55-69 years were enrolled into the NLCS. Mortality data were collected over a 10-year follow-up period. Analysis was done through a case-cohort approach, and it was based on the subjects without a history of heart disease, stroke or diabetes at baseline. A total of 1789 IHD mortality cases and 708 stroke mortality cases occurred during the follow-up. Higher total fluid consumption was not associated with either IHD mortality or stroke mortality in men or women. When analysing specific beverages, a positive association between coffee consumption (increment 270 ml/d) and IHD mortality was observed in men (hazard ratio (HR) 1.09, 95% CI 1.00, 1.18), while an inverse relationship was observed in women (HR: 0.88, 95% CI 0.78, 1.00). For tea consumption (increment of 253 ml/d), an inverse relationship with IHD mortality was observed in men (HR: 0.91, 95% CI 0.83, 1.00). No association with water intake was observed. In the study population, fresh water consumption was very low. In conclusion, total fluid intake was not associated with IHD or stroke mortality in either men or women. Coffee consumption was inversely associated with IHD mortality in women only, while a higher tea intake was associated with lower IHD mortality in men only.