New research has revealed people with severe high blood pressure may face double the risk of death from cardiovascular disease if they drink two or more coffees daily.
The findings apply to coffee drinkers with a blood pressure of 160/100 mm Hg or higher – not to people whose high blood pressure is not considered severe.
The researchers also found that those who only drank one coffee a day and consumed green tea daily were not at greater risk of cardiovascular disease, whatever their blood pressure measurement, even though both drinks contain caffeine.
- Regular coffee drinking may prevent development of type 2 diabetes in women who had gestational diabetes
- Drinking tea and coffee reduces mortality risk, large-scale study finds
The 19-year long study involved more than 6,570 men and 12,000 women, aged from 40 to 79 at the start of research, who were chosen from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk.
Previous studies have indicated that a coffee a day may be beneficial to the health of heart attack survivors and may prevent heart attacks or strokes in healthy people.
It has also been suggested in other studies that drinking coffee regularly may reduce people’s risk of developing some chronic illnesses, may help to lower the risk of depression and may help to control appetite.
The study’s senior author, Hiroyasu Iso, MD, PhD, MPH, director of the Institute for Global Health Policy Research, Bureau of International Health Cooperation, National Center for Global Health and Medicine in Tokyo, Japan, and professor emeritus at Osaka University, said: “Our study aimed to determine whether the known protective effect of coffee also applies to individuals with different degrees of hypertension; and also examined the effects of green tea in the same population.
“To the best of our knowledge, this is the first study to find an association between drinking two or more cups of coffee daily and cardiovascular disease mortality among people with severe hypertension.
- Drinking coffee increases lifespan and prevents heart disease
- Study sheds light on why smokers enjoy a coffee with their morning cigarette
He continued: “These findings may support the assertion that people with severe high blood pressure should avoid drinking excessive coffee.
“Because people with severe hypertension are more susceptible to the effects of caffeine, caffeine’s harmful effects may outweigh its protective effects and may increase the risk of death.”
The researchers concluded that further study is needed to discover more about the effects of coffee and green tea consumption in people with high blood pressure.
The research was published in the Journal of the American Heart Association.
