Moderate drinkers and exercisers have performed better on various cognitive tests than non-drinkers and sedentary members of the study. 'It suggests that exercise may be protective.'

Taken as a whole, the research suggests that even though family history might predispose a person to developing Alzheimer's, various behaviors -- if started early enough in life -- might help preserve cognitive function and delay the onset of the disease.

"The best time to intervene is at birth," said Mark Sager, a professor of medicine at the University of Wisconsin-Madison. "What we are hoping is that 55 is not too late."

The lifestyle measures, many of which are also good for the heart, were presented in several studies in Washington on Sunday at the first Alzheimer's Association International Conference on the Prevention of Dementia.

Exercise May Be Protective

The findings come amid growing concern about a looming surge in Alzheimer's cases in the years ahead as America ages. Already, nearly 5 million people have the disease, and with the vanguard of the baby boom generation about to turn 60, the number of cases is expected to increase 70% by 2020.

Sager presented findings from the ongoing Wisconsin Registry for Alzheimer's Prevention, a study of nearly 500 middle-aged children of Wisconsin residents who had Alzheimer's disease.

The study's subjects, who now are an average age of 53, have been followed for five years.

So far, moderate drinkers and exercisers have performed better on various cognitive tests than non-drinkers and sedentary members of the study.

"It suggests that exercise may be protective," said Sager, director of the Wisconsin Alzheimer's Institute.

Moderate drinkers also did better on verbal fluency tests than non-drinkers, he said.

Sager said he would not recommend that people at risk for the disease begin drinking, although he would not discourage anyone who can handle a glass or two of wine a day.

"It's all moderation," he said.

Fruit and Vegetable Juices

However, a second study suggests that fruit and vegetable juices might be just as effective as alcohol.

It looked at juice consumption in 1,800 older Japanese-American men and women in Seattle.

Those who drank at least three glasses of juice a week had a 75% lower risk of developing dementia than those who drank less than one glass of juice a week.

"This is the first study to try to get at polyphenol exposure," said Amy Borenstein of the University of South Florida's College of Public Health.

Polyphenols, also known as flavonoids, are substances found in plants that have antioxidant properties.

Borenstein said polyphenols generally are found in higher concentrations in juices than in whole fruits and vegetables.

A third study followed 109 pairs of identical twins in Sweden to find any lifestyle factors associated with developing dementia.

"Studying twins allows us to isolate genetic and non-genetic factors," said lead author Margaret Gatz of the University of Southern California and Karolinska Institute in Stockholm.

The study found that twins who had suffered a stroke were six times more likely to develop dementia, those who had periodontal disease earlier in life were four times more likely, and those with lower levels of education were 1.6 times more likely.

Gum disease is considered a marker for inflammation, which is believed to play a role in brain cell death.

Higher levels of education as well as staying mentally active might help people develop more brain reserve power.

"Good brain health in old age reflects influences that begin much earlier in life," Gatz said.