(PhysOrg.com) -- By stripping patients of their memories, Alzheimers disease gradually robs people of their very identities. Patients eventually lose the ability to care for themselves and to control basic bodily functions, such as swallowing and urination. No one has a cure.
Its little wonder, then, that Alzheimer's-prevention tips proliferate on the Web and in the media. Many urge older people to stay mentally agile by doing crossword puzzles, learning new languages, or remaining socially engaged.
Unfortunately, there is no strong evidence that such activities actually prevent the disease, said Philip Sloane, MD, MPH, a professor of family medicine at the University of North Carolina at Chapel Hill.
Id be surprised if it actually makes a difference, he said.
In April, an independent panel convened by the National Institutes of Health concluded that there is no evidence of even moderate scientific quality that any intervention, including exercise, drugs, dietary supplements or increased social engagement, reduces the risk of Alzheimer's disease.
The disease sickens people by damaging and killing nerve cells. Abnormal structures beta-amyloid plaques and a twisted protein fragment called tau form in the brain. They build up first in memory regions and then spread to other regions.
The disease most often strikes people older than age 65, but it can also affect people in their 30s, 40s and 50s, according to the Alzheimer's Association. About 5.3 million Americans have Alzheimer's disease.
An Alzheimer's patient usually deteriorates over the course of years, and damage to the brain often begins before others notice memory lapses. That slow onset requiring years of study to track is a challenge in researching prevention strategies, Sloane said.
In addition, researchers must also show whether activities linked to reduced risk actually prevent the disease. For example, maintaining a wide network of friends might help your brain stay healthy. But the reverse is also true: If you have a healthy brain, you may be more likely to have plenty of friends. Observational studies, which track groups of people over a number of years, cant distinguish between cause and effect in such cases.
But Daniel Kaufer, MD, an associate professor of neurology and director of the UNC Memory Disorders Clinic, said that even if you cant prevent the disease, you may be able to delay onset. Avoiding metabolic syndrome may be particularly important in staving off the disease.
Metabolic syndrome is a group of conditions, including high blood pressure, extra weight around the waist, elevated insulin levels and abnormal cholesterol, that increase the risk of cardiovascular diseases and diabetes. Over the long term, abnormalities in the bodys metabolic activity may harm the brain, Kaufer said.
Although not definitive, current evidence suggests exercise may delay the onset of Alzheimer's disease, he said.
The kinds of things that are good for your body are also good for your brain, he said.
You should also take steps to prevent serious head injuries, which have been linked to the disease. That means that you should wear a seat belt in the car, put on a bike helmet and remove fall hazards from your home.
In addition, you should avoid smoking, eat plenty of fresh vegetables and work with your doctor to control blood pressure, cholesterol and diabetes, Kaufer said. Like making deposits in a bank account, the sooner you develop lifetime healthy exercise and eating habits, the better off youll be.
The cumulative effect really makes the difference, he said. If you keep making deposits, youll accumulate lower risk over time.
If nothing else, exercising and eating well will decrease your risk for developing other diseases: Its better to have one disease than to have two, Sloane said.