Getting to heart of drink debate


When it comes to your heart, coffee has taken a couple of lumps in the past year, although in a recent large study it got a clean bill of health. Tea, on the other hand, consistently is portrayed as a heart-healthy beverage, although the Food and Drug Administration recently denied that claim once again.

Coffee and tea have been studied intensely in the past several years, and while medical science has not definitively decided how the popular beverages affect the heart, it is inching closer to a conclusion.

This year, two studies suggested that the less coffee a person drinks, the better.

In March, a study that followed more than 3,000 coffee drinkers in Greece for two years found troubling levels of inflammatory substances in their blood, compared with the blood of those who don't drink coffee.

In other studies, those substances have been associated with higher rates of heart attack and stroke, although the new study did not assess whether the coffee drinkers were at more risk.

The study, which was presented at the American College of Cardiology annual meeting, found that men who consumed more than a cup of coffee a day had 30 percent higher levels of a particular inflammatory substance in their blood, compared with noncoffee drinkers. For women, it was 38 percent higher.

Various other inflammatory substances also were elevated in the coffee drinkers.

"Maybe [coffee] is harmful when you consume high quantities," said lead author Christina Chrysohoou, a cardiologist with the First Cardiology Clinic at the University of Athens in a March interview. "Moderate consumption is the best."

Just before that study, another one found a troubling link between coffee consumption and nonfatal heart attacks in patients who had a specific genetic trait related to how quickly they metabolized caffeine. About 50 percent of the U.S. population has that trait.

That study, published in March in the Journal of the American Medical Association, involved 2,014 first heart-attack patients in Costa Rica.

Those who slowly metabolized caffeine and who drank two to three cups of coffee a day had a 36 percent greater risk of having a nonfatal first heart attack. For those who drank four or more cups, the risk was 64 percent greater.

However, for those who were genetically predisposed to rapidly metabolize caffeine, drinking up to three cups of coffee a day brought as much as a 22 percent reduction in heart-attack risk.

More reassurance came from a huge prospective study published in May that essentially gave coffee, at least filtered coffee, a clean bill of health.

The study, which followed 128,000 men and women for up to 20 years, found no evidence that coffee drinking increased the risk of coronary heart disease.

"We basically have cleared coffee's name," said senior author Dr. Frank Hu, an associate professor of nutrition and epidemiology at the Harvard School of Public Health. "There is no hint of increased risk."

In fact, those who drank more than six cups a day had a reduced risk of heart disease, according to the study published in Circulation, a journal of the American Heart Association.

"We don't want to make too much of that," warned Hu, who said that finding could be due to chance.

Hu noted, however, that other research suggests coffee might protect against diabetes, Parkinson's disease and gallstones. Last month, a separate study in the Archives of Internal Medicine found that coffee may help prevent the liver disease alcoholic cirrhosis.

"It seems that coffee is more helpful than harmful," Hu said.

One caution, he said, is that boiled, unfiltered coffee may increase cholesterol, but nearly all coffee in the United States is filtered.

Hu said the other big concern is high-calorie and high-fat coffee drinks.

"Too much sugar and cream may create some health concerns," he said.

While coffee appears to be fairly benign toward the heart, there are other reasons to limit consumption, said Dr. Paul J. Millea, an assistant professor of family medicine at the Medical College of Wisconsin.

It can contribute to ulcers and gastroesophageal reflux disease, he said.

Beyond that, drinking large amounts of coffee may be a sign of another concern.

"If we are downing multiple cups of coffee a day, why is it?" he said. "Usually it's because of some hyperstressed lifestyle."

He recommends limiting consumption to one to two cups a day.

But what about green tea?

Last month, researchers at Yale University School of Medicine weighed in on the issue with a review article that looked at more than 100 studies on the health benefits of green tea.

More studies are needed, they said. But they pointed to what they called an "Asian paradox," which refers to lower rates of heart disease and cancer in Asia despite high rates of cigarette smoking.

They theorized that the 1.2 liters of green tea that is consumed by many Asians each day provides high levels of polyphenols and other antioxidants.

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