Think twice about that occasional cup of coffee

According to new research, one cup of coffee may trigger a heart attack in some people within a hour of drinking it.

The risk they say is highest among people with light or occasional coffee habits and those with a sedentary lifestyle and risk factors for coronary heart disease.

Researchers at Brown University and Harvard School of Public Health carried out a study in Costa Rica into 503 cases of non-fatal myocardial infarction.

Ana Baylin and her team surveyed participants about their coffee consumption in the hours and days before their heart attack and also studied the participants’ socio-demographic characteristics, lifestyle, and medical history.

They suggest that caffeine causes short-term increases in blood pressure and sympathetic nervous activity that could affect a vulnerable atherosclerotic plaque, and trigger a heart attack.

The researchers found that the moderate coffee drinkers, by having a cup of coffee, increased their risk of having a heart attack by 60% but there was little effect among heavy coffee drinkers, but light coffee drinkers increased their risk of heart attack by more than four times.

Baylin says this may be because lighter drinkers are less used to the effects of caffeine.

The researchers also found that patients with three or more risk factors for coronary heart disease more than doubled their risk.

Baylin, an assistant professor in the Department of Community Health at Brown University, in Rhode Island, suggests that people at high risk for a heart attack who are occasional or regular coffee drinkers might consider giving up coffee altogether.

As previous research has suggested that coffee does not raise heart risks, and might even protect against high blood pressure and diabetes and only decaffeinated coffee has been shown to possibly boost the chances of cardiovascular trouble, this latest study, the first to examine the immediate effects rather than those that impact people’s health long-term, might make some think twice about that cappuccino.

Although the study was conducted in Costa Rica, the researchers say that the results are relevant to the U.S. since Americans’ caffeine intake is comparable.

But it is worth noting that only the short-term effects of coffee were examined and the results do not necessarily apply to the general population.

Other experts are not convinced about the coffee-heart attack link and suggest more research is needed.

The study is published in the journal Epidemiology.