2004-05-23
JOHN FAUBER

jfauber@journalsentinel.com

San Francisco - It wasn't long ago that doctors believed little could be done to stave off incurable brain diseases such as Alzheimer's and Parkinson's.

Unlike heart disease and another leading killer, lung cancer, it was thought that people avoided or contracted those and other neurological disorders largely in spite of their lifestyles, habits or precautions.

But in the last few years a wealth of population-based studies suggest it may be possible to reduce the risk of such diseases or to delay symptoms to later in life.

Can frequent vitamin E use prevent ALS? Can staying trim keep Alzheimer's at bay? Can vigorous exercise spare men from Parkinson's?

"Scientists are skeptical," said Robert Daroff, former editor of the journal Neurology and a professor of neurology at the University Hospitals of Cleveland and Case Western Reserve University. "There is data now."

Not yet proof, many of the studies merely are observations that note associations between certain activities and a lowering of the odds of getting specific age-related brain diseases.

Indeed, until the causes of such diseases are known, measures to prevent them never will be certain. Proof also will require long-term prospective studies.

But a big difference between today and just five years ago is there is much more reason to be optimistic about preventive measures, including several that are painless, sometimes enjoyable and often likely to prevent other diseases.

"Part of it is just the evolution of knowledge in the field," said Deborah Gustafson, an assistant professor of family and community medicine at the Medical College of Wisconsin. "Finally, some of these studies that have been going on for years are getting to end points. That's especially true for Alzheimer's and Parkinson's.

"You can modify your risk."

Last month, at the annual meeting of the American Academy of Neurology, scientists from around the world presented a variety of studies showing that the risks of various brain disorders can be lowered.

Here are a few of the findings:

Alcohol's effects

While excessive drinking is known to impair cognitive function, the role of moderate drinking is unclear. Several studies have showed that it's good for the heart.

Is it also good for the brain?

Looking at 11,102 women aged 70 to 80, Harvard University researchers found that moderate drinkers had better scores on several cognitive tests and were less likely to see a decline in mental skills than non-drinkers.

For the study, moderate drinking was defined as about one drink per day. And the type of beverage did not seem to make a difference.

"It's plausible," said Glenn Graham, director of the cerebral vascular disorders program at the University of New Mexico and the Albuquerque Veterans Administration Hospital. "Certainly, heavy drinking has lots of complications."

Graham, who was not involved in the research, said alcohol may help prevent micro damage to the bloodvessels of the brain, resulting in fewer strokes.

Diabetes and obesity

Earlier this month, a study of 824 middle-aged Catholic priests and nuns found that those with type 2 diabetes were 65% more likely to later develop Alzheimer's than those who were not diabetic. The research was published in the Archives of Neurology.

A separate study presented at the neurology conference in April adds credence to that finding.

Researchers at Case Western Reserve University found that obesity in midlife may predispose a person to developing Alzheimer's. Obesity is a leading cause of diabetes.

The study compared a group of 86 people with Alzheimer's with 209 who did not have the disease. It found that being obese between the ages of 40 and 59, as opposed to just overweight, increased the risk of later getting Alzheimer's by 4.6 times. However, merely being just overweight did not appear to increase the risk of developing Alzheimer's.

Heart disease risks

In another study presented at the conference, having any or all four of the primary risk factors for heart disease in midlife also increased the risk of developing dementia.

The study involved 11,341 men and women 40 to 44 who were followed over 30 years.

High cholesterol increased the risk by 39%; high blood pressure by 20%; diabetes by 34%; and smoking, 14%.

Those who had all four risk factors were 2.6 times more likely to develop dementia than those with none of the risk factors.

The advantage of exercise

Whether exercise can significantly reduce the risk of Parkinson's still is unclear.

But a study involving more than 125,000 men and women conducted by researchers at Harvard University, found that men who engaged in regular vigorous physical activity were 30% to 50% less likely to later develop Parkinson's than men who were inactive.

Animal research suggests that exercise affects dopamine levels in the brain and also helps brain cells survive after they are exposed to a chemical that induces a Parkinson's-like disorder, said HongLei Chen, lead author and a Harvard epidemiologist.

However, physically active women in the study did not have a reduced risk, a finding the researchers could not explain.

Migraines

A three-month Swiss study of 42 migraine sufferers showed those who took three, 100-milligram pills of coenzyme Q10 each day had fewer headaches and headache days and less nausea than those who got a placebo.

Coenzyme Q10 is an anti-oxidant that is needed to produce energy in cells.

"A lack of cell energy in the brain may be a cause of migraine," lead author Peter Sandor, a researcher at University Hospitals in Zurich said in a statement.

The study was funded by a company that makes dietary supplements.

Some preliminary research suggests coenzyme Q10 also may slow the progression of symptoms in early-stage Parkinson's.

ALS and vitamin E

Regular use of vitamin E may lower a person's risk of getting ALS, according to a Harvard study of 1.2 million people, including 525 who died of ALS.

Men and women who took the supplement at least 15 times a month for more than 10 years had 62% less chance of getting the disease than those who did not take vitamin E at all.

Oxidative stress is thought to contribute to ALS, as well as many other diseases.

Vitamin E is an anti-oxidant that may help stabilize free radicals, unstable oxygen-bearing molecules that contribute to oxidative stress.

"Vitamin E is probably good for a lot of things," said co-author Marc Weisskopf, a Harvard epidemiologist.

No significant protection was found among those who used vitamins A or C or multivitamins.

Statin drugs

Whether cholesterol-lowering statin drugs can prevent Alzheimer's is an area of active research. Some studies suggest the drugs may be beneficial; others find they are not. In addition, in a small number of people, the drugs have been linked to memory problems.

A three-year French study of 342 Alzheimer's patients suggests that the drugs may slow cognitive decline.

Patients treated with statins had somewhat less decline in their cognitive test scores than those who did not get the drugs.

Piero Antuono, a professor of neurology at the Medical College of Wisconsin who was not involved in the study, said the drugs seemed to show a modest effect.

Antuono said it is possible the drugs reduce Alzheimer's risk, not so much by lowering cholesterol, but by reducing inflammation.

He said what is needed are large trials involving statins and placebos.

"We definitely have to have proof," he said. "These are not benign medications."

A separate study published recently in the journal The Lancet found that statins may also help treat multiple sclerosis.

In a six-month trial, 30 MS patients were given a high-dose statin. Researchers at the Medical University of South Carolina said they found a 44% reduction in brain lesions.

Graham, of the University of New Mexico, said the vast majority of studies researching ways to prevent brain disease have come out in the last five years. More are needed, he said.

"I think we are finding more leads," he said. "There are things you can do that can really make a difference to your risk.

"Preventing a condition is really the best way to go."