Genetic caffeine-related heart attack risk

A genetic mutation increases some people’s risk of having a heart attack if they drink too much coffee.

Caffeine is mainly metabolised in the liver by an enzyme (CYP1A2). A mutation in the gene that interacts with this enzyme alters the rate at which the body breaks down caffeine. US researchers have examined the genes of over 4000 people to test the effect of CYP1A2 mutations on heart attack risk. Only carriers of the gene mutation for slow caffeine metabolism were at increased risk of heart attack.

Those who drank two or more cups of coffee daily were at least 36% more likely to have a non-fatal heart attack than those who drank little or no coffee. It’s worth noting the results of this study are not conclusive. Coffee can trigger heart palpitations in people who are sensitive to caffeine but may not be harmful.

Source: Journal of the American Medical Association, March 2006