Caffeine consumption and cardiovascular disease risk:
In a population study researchers found that consumption of coffee, green tea and oolong tea and total caffeine intake was linked to a reduced risk of death from cardiovascular disease (CVD). Participants included 76,979 adults followed for 1,010,787 person years, all of whom were ages 40 to 79 and free of stroke, heart disease, and cancer at the start of the study. Researchers determined that compared to non-coffee drinkers, men consuming 1-6 cups/week, 1-2 cups/day and ≥ 3 cups/day had a protective effect from coffee with a 22%, 33%, and 55% less rate of stroke occurrence than the control population. The multivariate hazard ratio,(HR), (or ratio of hazard rates from coffee drinkers to non-coffee drinkers) was 0.78 (range 0.50 to 1.20), 0.67 (range 0.47 to 0.96) and 0.45 (range 0.17 to 0.87) respectively for strokes among men (p = 0.009). Compared with non-tea drinkers, women consuming 1-6 cups/week, 1-2 cups/day, 3-5 cups/day and ≥ 6 cups/day had a 66%, 72%, 61%, and 58% reduced rate of coronary heart disease compared to non-tea drinkers. Multivariable hazard ratios were 0.34 (0.06-1.75), 0.28 (0.07-1.11), 0.39 (0.18-0.85) and 0.42 (0.17-0.88) respectively(p = 0.038 for trend). Men drinking ≥ 1 cups/day of oolong tea benefited from a 61% reduced rate of CVD (the HR was 0.39, with range of 0.17-0.88) when compared to non-tea drinkers, (p = 0.049 for trend). Individuals in the second highest quintile of total caffeine intake had a total CVD risk reduction of 38% in men and 22% in women. (46)