In America, roughly 400 million cups of coffee are consumed every day. But, according to a new study, this could be bad news for people under the age of 55. Looking at more than 40,000 individuals, the researchers found that people who drank more than 28 cups of coffee a week experienced a 21 percent increased mortality risk. When looking at coffee drinkers under 55, this number jumped to a 50 percent increased mortality risk. There were no adverse effects found in heavy coffee drinkers over the age of 55.
It has long been thought that coffee consumption contributes to a variety of chronic health conditions, though research is limited and the results are often controversial. The multicenter research team set out to investigate the effect of coffee consumption on death.
Nearly 45,000 individuals, between the ages of 20 and 87, completed a medical history questionnaire between 1979 and 1998. A total of 43,727 questionnaires, of which 33,900 were completed by men and 9,827 by women, were used in the final analysis. The questionnaires assessed lifestyle habits, including coffee consumption, as well as personal and family medical history.
During the 17-year follow-up period, 2,512 deaths occurred, of which 32 percent were caused by cardiovascular disease. Both men and women who consumed higher amounts of coffee were more likely to smoke and had lower fitness levels.
Younger men tend to experience a higher mortality, even at lower consumption, which became significant at about 28 cups per week when there was a 56 percent increase in mortality. Younger women also saw a two-fold increase in mortality risk when consuming more than 28 cups of coffee per week relative to those who did not drink coffee. Significantly, the results did not indicate any relationship between coffee consumption and mortality among older men and women.
Recent research has shown that coffee is a major source of antioxidants and has the potential to reduce inflammation and increase cognitive function. However, potentially adverse effects arise from caffeine’s ability to stimulate the release of epinephrine, inhibit insulin activity, and increase blood pressure.
It’s unknown whether all of these mechanisms counterbalance one another. Research also suggests that heavy coffee drinkers could be genetically pre-disposed to excessive coffee consumption experience. This combined with other risk factors associated with coffee drinking, like smoking, could create the positive association seen between coffee and mortality.
“People who drink more coffee may be prone to higher mortality; however, this may not be cause-and-effect, as there may be something else about the person who drinks 10 cups per day such as an addicting personality or is easily stressed out,” co-author Carl J. Lavie, medical director of cardiac rehabilitation and prevention at Ochsner Medical Center in New Orleans, told MedPage Today.
The researchers suggest that younger people especially should avoid heavy coffee consumption. However, further studies are needed across different populations to assess the effects long-term coffee consumption and changes in coffee consumption have on mortality.