Cognitive declines are an unfortunate side effect of aging. For scientists to better understand how to prevent it from happening they look to those lucky few who age and remain mentally sharp. One particular group being studied are people over the age of 90 who live in a retirement community.
Laguna Woods Village, a sprawling retirement community of 20,000 south of Los Angeles, is at the center of the world’s largest decades-long study of health and mental acuity in the elderly. Begun by University of Southern California researchers in 1981 and called the 90+ Study, it has included more than 14,000 people aged 65 and older, and more than 1,000 aged 90 or older.
A favorite game requiring a sharp memory is contract bridge. Since forming new memories is one of the first things to be impaired with the onset of dementia, routine players can easily tell when another member begins to have problems.
“When a partner starts to slip, you can’t trust them,” said Julie Davis, 89, a regular player living in Laguna Woods. “That’s what it comes down to. It’s terrible to say it that way, and worse to watch it happen. But other players get very annoyed. You can’t help yourself.”
The real question researchers are trying to answer is whether people who stay involved in mentally engaging activities, such as playing bridge, doing crossword puzzles, or socializing keep themselves sharp as a result of their activities or if they participate in those things because they are already mentally fit. In some cases there appears to be a genetic component.
In studies of the very old, researchers in California, New York, Boston and elsewhere have found clues to that good fortune. For instance, Dr. Kawas’s group has found that some people who are lucid until the end of a very long life have brains that appear riddled with Alzheimer’s disease. In a study released last month, the researchers report that many of them carry a gene variant called APOE2, which may help them maintain mental sharpness.
Dr. Nir Barzilai of the Albert Einstein College of Medicine has found that lucid Ashkenazi Jewish centenarians are three times more likely to carry a gene called CETP, which appears to increase the size and amount of so-called good cholesterol particles, than peers who succumbed to dementia.