Coffee: how much is too much?(Your Health)(Column)

If you're among the roughly 160 million Americans who drink coffee, you've probably followed news reports that implied the brew could damage your health--particularly since it contains caffeine, a potent, potentially habit-forming stimulant. Over the past few decades, coffee has been linked to an array of possible health risks, ranging from stroke and miscarriage to high cholesterol and even cancer.

But now the jury is pretty much in, and for most people, the news is good: Consuming two or three cups of coffee a day does no harm; it boosts mood, alertness, and physical performance; and it may even help prevent certain diseases. However, the news isn't bracing for everyone: Heavy coffee drinkers, pregnant women, and possibly people with heartburn, breast lumps, or anxiety disorders may benefit from cutting back on the brew. Here's a look at the latest findings on what coffee does to the body and mind.

SAFE FOR THE AVERAGE HEART

The idea that coffee is bad for your heart pops up periodically--and seems to have a certain logic. Over a decade ago, several epidemiologic studies found that heavy coffee drinkers had higher blood-cholesterol levels than nondrinkers. Then lab tests, mainly from Europe, found that regularly drinking very strong coffee could sharply increase volunteers' cholesterol levels. Researchers even isolated a fatlike chemical in coffee, cafestol, that was clearly responsible for the rise. (Cafestol shows up in coffee whether or not it's decaffeinated.)

However, the brewing methods used in the lab studies involved boiling ground coffee in water, a method that produces extremely high concentrations of cafestol. By contrast, the filter and percolation brewing methods used by more than nine of ten Americans remove all but a trace of cafestol. (So-called French-press brewing results in a cafestol content close to that of the boiling method.)

Moreover, the laboratory studies involved large amounts of coffee--six cups a day of boiled brew. The average American coffee drinker downs about three cups a day.

In addition, research has clearly shown that regular moderate coffee drinking doesn't substantially raise blood pressure. Studies have also failed to substantiate fears that coffee might trigger or worsen abnormal heart rhythms (arrhythmias).