LEXINGTON, Ky. — In 1982, 22,071 male doctors said they'd be happy to be part of a study to see whether a single tablet of aspirin would reduce their risk of heart attack. They were the right age — between 40 and 84. They were healthy, with no history of heart disease. Not much else was noted — not how much they smoked or what they weighed or whether they liked a good thick steak every night.

One group took 325 mg of aspirin and another took 325 mg of sugar. The study was called the Physicians' Health Study, and it was supposed to last through 1990.

By March 1988, an independent board looking at the data had seen enough. The aspirin regimen produced a 47 percent reduction in the total incidence of heart attacks.

It's been 20 years since the first news. Last spring, researchers at the University of Kentucky published findings that might have changed some thinking in the medical profession. In short, they said that not everyone needs an aspirin a day. And if you do, they said, you sure don't need 325 mg.

Two of those researchers — cardiologists Charles Campbell and Susan Smyth at UK's Gill Heart Institute — recently explained their work and the most current findings about aspirin and heart health.

QUESTION: What was the crux of your findings?ANSWER: In a review of numerous trials employing aspirin as a preventative and as subsequent regimen after an initial heart attack, we could not find a benefit from taking the higher (1 adult tablet, 325 mg.) dose over taking a quarter of that (one baby aspirin, 81 mg.) dose.

QUESTION: So taking a baby aspirin a day is now what should be recommended?A: If it's warranted. No one should begin an aspirin regimen without first speaking to a doctor or healthcare provider. Things like your blood pressure and cholesterol count and family history are what's important in determining your risk of heart attack, and those should be analyzed before any regimen is begun.In general, if it's been determined that you have a 10 percent chance of having a heart attack in the next 10 years, the aspirin regimen is advisable. Obviously, the higher the risk, the more benefit you accrue.

QUESTION: If it's warranted and I am diligent in taking it daily, am I absolutely reducing my risk of heart attack?ANSWER: It's hard to prove the negative. And it may matter if you are male or female. In studies with men, there is reasonable data to suggest that taking an aspirin will reduce heart attack risk but not stroke. (It should be noted that men suffer heart attacks about 10 years earlier in life — i.e., in their 50s — than women do.) And in studies with women, the effect of the regimen seems to be reducing stroke but not heart attack.

QUESTION: But what about if I'm having a heart attack?ASWER: Get an aspirin into you as quickly as you can. In an emergency room setting, that's 162 mg. — or two baby aspirins — but 325 mg. is fine. Chew it so that it dissolves and gets into your bloodstream with haste. Some 250,000 people die of heart attacks each year before they reach a hospital. That number could be reduced if more would recognize the symptoms of a heart attack and act accordingly.

QUESTION: Do Tylenol, Motrin or Aleve work the same way?ANSWER: No. Those are acetaminophen products and do not have the same mechanism. However, do not take these drugs and aspirin together, as they compete for the same binding sites and may blind each other's positive effects.

QUESTION: Does coated aspirin work?ANSWER: That's not really clear, but absolutely do not use it in the acute setting — where you're in the midst of a heart attack. It would take too long to get into your system.Q: Who should not take a daily dose of aspirin to prevent heart attack?A: Anyone at low risk of having a heart attack. If there is not much benefit of using the drug or any drug, all that you're left with is the side effects and, in the case of aspirin, that can be bleeding into the stomach or intestines or an allergic reaction.Q: Is there any evidence that an aspirin regimen is valuable in treatment of other diseases?A: Yes. In a study following 90,000 American nurses for 20 years, those who reported taking a regular dose of aspirin experienced half the colon cancer as those who did not take aspirin. This is called observational evidence, and it (also) suggests that those women who regularly take aspirin have a slightly lower risk of having breast cancer. The question is if taking the aspirin is what causes the slight variation in incidence. Much more work is needed. The results of a randomized controlled study by researchers at Harvard Medical School are expected this year.Q: If I am not advised to take an aspirin regimen, what should I be doing to protect my heart against attack?A: Exercise regularly. Eat lots of fruits and vegetables. Don't smoke. Drink only in moderation. Know what your blood pressure, blood sugar and cholesterol readings are. Have regular checkups to monitor your overall heart health.