For decades I've been pleading with my readers to adopt healthy habits to prevent heart disease and possibly some cancers.
Growing, scientifically sound evidence suggests that people can delay and perhaps even prevent the onset of Alzheimer's disease by taking steps like eating low-fat diets rich in antioxidants, maintaining normal body weight, exercising regularly and avoiding bad habits like smoking and excessive drinking.
Several other practices --- including remaining socially connected and keeping the brain stimulated by reading, doing puzzles and learning things --- also appear to protect the brain against dementia.
By 2010, Medicare costs for people with Alzheimer's are expected to rise by more than 50 percent, to $49.3 billion from $31.9 billion in 2000.
Two changes in the brain are characteristic: abnormal microscopic structures called amyloid plaques that accumulate outside brain cells, and tangles of a protein called tau that form inside brain cells.
Because these changes are now seen only in autopsies, coming up with early diagnoses and tests for the disorder is a major challenge.
Witness how well some people recover from serious strokes and brain trauma.
Likewise, autopsies often reveal considerable brain changes associated with Alzheimer's disease among subjects who showed no symptoms of dementia during their lives.
The presence of vascular disease --- the kind that can lead to a heart attack or stroke --- seems to decrease the brain's ability to fend off the effects of Alzheimer's-related damage and increase a person's chances of showing obvious signs of dementia.
The same risk factors that raise a person's chances of having a heart attack or stroke --- high cholesterol and blood pressure, excess weight, smoking, lack of exercise --- also raise the risk of developing dementia, she explained.