Choy-Lye Chei1, Julian Kenrick Loh2, Avril Soh3, Jian-Min Yuan4,5, Woon-Puay Koh6,7. 1. Office of Clinical Sciences, Duke-NUS Medical School, Singapore, 169857, Singapore. 2. National Heart Center Singapore, Singapore, 169609, Singapore. 3. Saw Swee Hock School of Public Health, National University of Singapore, Singapore, 117549, Singapore. 4. Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA. 5. Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA. 6. Office of Clinical Sciences, Duke-NUS Medical School, Singapore, 169857, Singapore. woonpuay.koh@duke-nus.edu.sg. 7. Saw Swee Hock School of Public Health, National University of Singapore, Singapore, 117549, Singapore. woonpuay.koh@duke-nus.edu.sg.
Abstract
PURPOSE: The relationship between coffee and tea, and risk of hypertension remains controversial in Western populations. We investigated these associations in an Asian population. METHODS: The Singapore Chinese Health Study is a population-based prospective cohort that recruited 63,257 Chinese aged 45-74 years and residing in Singapore from 1993 to 1998. Information on consumption of coffee, tea, and other lifestyle factors was collected at baseline, and self-reported physician-diagnosed hypertension was assessed during two follow-up interviews (1999-2004, 2006-2010). RESULTS: We identified 13,658 cases of incident hypertension after average 9.5 years. Compared to those who drank one cup of coffee/day, the hazard ratios (HR) and 95% confidence intervals (CI) were 0.87 (0.83-0.91) for <weekly drinkers and 0.93 (0.86-1.00) for ≥3 cups/day drinkers. Compared to <weekly drinkers, daily drinkers of black or green tea had slight increase in risk, but these risk estimates were attenuated and became non-significant after adjustment for caffeine. After adjusting for coffee, there was a stepwise dose-response relationship between caffeine intake and hypertension risk; compared to the lowest intake (<50 mg/day), those in the highest intake (≥300 mg/day) had a 16% increase in risk; HR 1.16, 95% CI 1.04-1.31 (p trend = 0.02). CONCLUSIONS: Drinking coffee <1 cup/week or ≥3 cups/day had lower risk than drinking one cup/day. Caffeine may account for increased risk in daily tea drinkers and in those who drank one cup of coffee/day. The inverse U-shaped association with coffee suggests that at higher doses, other ingredients in coffee may offset the effect of caffeine and confer benefit on blood pressure.
PURPOSE: The relationship between coffee and tea, and risk of hypertension remains controversial in Western populations. We investigated these associations in an Asian population. METHODS: The Singapore Chinese Health Study is a population-based prospective cohort that recruited 63,257 Chinese aged 45-74 years and residing in Singapore from 1993 to 1998. Information on consumption of coffee, tea, and other lifestyle factors was collected at baseline, and self-reported physician-diagnosed hypertension was assessed during two follow-up interviews (1999-2004, 2006-2010). RESULTS: We identified 13,658 cases of incident hypertension after average 9.5 years. Compared to those who drank one cup of coffee/day, the hazard ratios (HR) and 95% confidence intervals (CI) were 0.87 (0.83-0.91) for <weekly drinkers and 0.93 (0.86-1.00) for ≥3 cups/day drinkers. Compared to <weekly drinkers, daily drinkers of black or green tea had slight increase in risk, but these risk estimates were attenuated and became non-significant after adjustment for caffeine. After adjusting for coffee, there was a stepwise dose-response relationship between caffeine intake and hypertension risk; compared to the lowest intake (<50 mg/day), those in the highest intake (≥300 mg/day) had a 16% increase in risk; HR 1.16, 95% CI 1.04-1.31 (p trend = 0.02). CONCLUSIONS: Drinking coffee <1 cup/week or ≥3 cups/day had lower risk than drinking one cup/day. Caffeine may account for increased risk in daily tea drinkers and in those who drank one cup of coffee/day. The inverse U-shaped association with coffee suggests that at higher doses, other ingredients in coffee may offset the effect of caffeine and confer benefit on blood pressure.
Authors: Patricia M Kearney; Megan Whelton; Kristi Reynolds; Paul Muntner; Paul K Whelton; Jiang He Journal: Lancet Date: 2005 Jan 15-21 Impact factor: 79.321
Authors: Win Pa Pa Thu; Inger Sundström-Poromaa; Susan Logan; Michael S Kramer; Eu-Leong Yong Journal: Hypertens Res Date: 2021-01-08 Impact factor: 3.872