The study of 11,000 people, published today in the Journal of Epidemiology and Community Health dispels the popular belief that coffee, which is known to alter heart rhythms, has a adverse effect on people's health.
The research, conducted on men and women in Scotland aged between 40 and 59, found that the risk of dying from a heart attack doubled for men if they drank five cups of tea rather than five cups of coffee. Likewise, women who drank tea were 50 per cent more likely to die from a heart attack than those who drank coffee.
Researchers sent questionnaires to randomly selected people as part of the Scottish Heart Health Study, asking them how much coffee, tea and alcohol they drank and other lifestyle questions such as whether or not they smoked. Those who took part in the study gave blood to be analysed and had the health of their hearts assessed.
The probability of death from all causes and the risk of heart attack and bypass surgery was then analysed according to the consumption of each individual. When adjustments were made for age, smoking, and blood pressure, there was still a moderate health benefit for those drinking coffee compared with no benefit for those who drank tea.
"This is an interesting finding which seems to contradict all previous studies, said Professor Hugh Tunstall-Pedoe, co-author of the study. "It might be attributable to a real effect of coffee or to chance. Coffee and tea drinking habits may be simply identifying two groups of people with very different lifestyles," he said.
The researchers found that in extreme cases people drank up to 21 cups of coffee and 36 cups of tea a day. Coffee drinkers tended to be younger and increasing tea consumption was found to be associated with increasing social and economic deprivation.Reuse content