Milwaukee ? Already proving good for the heart, light to moderate alcohol use also may be good for the brain.

In the strongest study to date, people who consumed one to six drinks a week had 54 percent less risk of developing various dementias, including Alzheimer’s disease, than abstainers, according to research published today in JAMA, the Journal of the American Medical Assn.

The provocative findings are likely to heat up the simmering debate about whether moderate alcohol use should be “prescribed” to help stave off various diseases.

In January, a separate study in the New England Journal of Medicine, found that those who drank several days a week or daily, but in moderate amounts, had up to a 37 percent reduced risk of having a heart attack.

But weighing against any alcohol recommendation are several serious concerns such as alcoholism, increased risk of breast cancer and possible interactions with medications.

For the moment, the authors of the study and other doctors are not recommending that people begin drinking. Instead, they say those who might be at greater risk for dementia or heart disease should discuss the matter with their doctor.

“The equation is pretty tricky,” said Kenneth Mukamal, the study’s lead author and an assistant professor of medicine at Harvard Medical School. “Before we can make wholesale recommendations, we need to determine whether targeted recommendations are even possible.”

For their study, Mukamal and his colleagues followed 373 people who would later develop dementia and 373 people who did not. The subjects, aged 65 and older, were part of the larger, multicenter Cardiovascular Health Study and were followed for up to seven years.

Compared with those who did not drink at all, the biggest reduction in dementia risk (54 percent) was found in those who drank one to six drinks a week. But those who drank less than one drink a week also had a reduction (35 percent) as did those who drank seven to 13 drinks (31 percent).

However, heavier drinking of 14 or more drinks a week actually increased the risk of developing dementia by 22 percent.

“People have believed that alcohol is toxic to neurons,” said Sanjay Asthana, head of geriatrics at the University of Wisconsin Medical School in Madison, Wis. “But there is a tight range within which it might be beneficial.”

Asthana described the Harvard study as very strong, but said it raises ethical concerns about the use of alcohol as means to prevent disease.

“To me, the data aren’t definitive,” he said. “They are strongly suggestive.”