Is Coffee a Risk Factor for MI? – It Depends . . .

Different studies give different results, so that it’s still a matter of dispute as to whether coffee drinking is a risk factor for a heart attack – an MI – or not. Now there’s a resolution, of sorts, to this dilemma. It depends on your genes.

A report in the Journal of the American Medical Association tells of a study in Costa Rica where the coffee-drinking habits of 2000 people who had had a heart attack were compared with those of 2000 healthy controls. The researchers also determined whether each subject was a ‘fast’ or ‘slow’ metabolizer of caffeine, depending on their genetic makeup. (Fast metabolizers break down caffeine in their bodies quickly – with slow metabolizers it hangs around longer. A similar type of problem is known for alcohol.)

There were about equal numbers of fast and slow metabolizers in the participants – both MI victims and healthy controls. When the risk of having an MI was examined in only the slow metabolizers, there was a clear increase, up to 2.3 times as great, in those drinking 4 cups of coffee a day or more. There was no such trend in the fast metabolizers.

These results suggest that drinking coffee was associated with an increased risk of heart attack only in those individuals who were ‘slow metabolizers’. Now if only there was a simple, cheap test to find out if one is part of the 55% who are, indeed, at risk. Cutting back on coffee is not something to be undertaken lightly!