If you want to drink the Java then best to make it a heavy regular habit.

A cup of coffee may cause a heart attack in some people within an hour of drinking it, according to a study reported in the journal Epidemiology (“Transient Exposure to Coffee as a Trigger of a First Nonfatal Myocardial Infarction,” (Volume 17, Issue 5, September 2006.) The risk was highest among people with light or occasional coffee intake, and those with a sedentary lifestyle or other risk factors for coronary heart disease.

Studying 503 cases of non-fatal myocardial infarction in Costa Rica, Ana Baylin of Brown University and her colleagues of Harvard School of Public Health surveyed participants about their coffee consumption in the hours and days before their heart attack. They also studied the participants’ socio-demographic characteristics, lifestyle, and medical history. They theorized 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%. There was little effect among heavy coffee drinkers, but light coffee drinkers increased their risk of heart attack by more than four times. This may be because lighter drinkers are less acclimated to the effects of caffeine. Baylin and her team also found that patients with three or more risk factors for coronary heart disease more than doubled their risk.

“People at high risk for a heart attack who are occasional or regular coffee drinkers might consider quitting coffee altogether,” comments Baylin, adding that for these individuals, a cup of coffee could be “the straw that broke the camel’s back.”

Also see my quite useful post Scientists Demonstrate Best Way To Use Caffeine.

Update: A New York Times survey of the health effects of coffee finds it has anti-inflammatory effects and studies have found that coffee reduces the risk of diabetes, liver cirrhosis, heart disease, and other disorders. The heart health benefit of coffee comes only in a sub-range of coffee consumption.

Some studies show that cardiovascular risk also decreases with coffee consumption. Using data on more than 27,000 women ages 55 to 69 in the Iowa Women’s Health Study who were followed for 15 years, Norwegian researchers found that women who drank one to three cups a day reduced their risk of cardiovascular disease by 24 percent compared with those drinking no coffee at all.

But as the quantity increased, the benefit decreased. At more than six cups a day, the risk was not significantly reduced.

The identification of the beneficial and harmful compounds in coffee and other foods will eventually lead to the development of foods which contain optimal concentrations of beneficial compounds and much less of the harmful compounds. Genetic engineering, breeding, and food processing methods will all be used to optimize the health benefits of foods based on increasing amounts of scientific knowledge..