The UCLA Longevity Center does massive research on the correlation between various behaviors and dementia and Alzheimer’s disease. For example, they have studied 18,000 participants aged 18 to 99. Here’s a summary of their recommendations from Dr. Gary Small, director of the UCLA Longevity Center at the Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA.
While there’s no cure for Alzheimer’s disease, Dr. Small says maintaining healthy habits can help stave off its symptoms. “Our programs help people create a lifestyle to bolster brain health,” he says. “They also teach them ways to compensate for the lowered function that naturally occurs with aging.”
Here are some key factors:
- Mental stimulation: Research shows that lifelong learning is associated with a lower risk for Alzheimer’s, but the cause-effect relationship hasn’t been proven. “Doing crossword puzzles, you may get better at those puzzles, but it may not transfer to your everyday life,” Dr. Small says. [My interpretation: the doctor is politely saying that a more rigorous learning regimen, such as writing about learned concepts, has more of a chance of actually making a difference to your brain’s cognitive abilities than doing crossword puzzles. For example, a famous longitudinal study of nuns in Kentucky correlated their chance of getting dementia to the quality of their entrance autobiographical essay. Those who wrote a “higher-quality” essay tended to get dementia less often than those whose essays were deemed lower-quality.]
- Nutrition: Being overweight doubles one’s risk for Alzheimer’s as does diabetes. Obesity quadruples the risk. Dr. Small says some research has shown that eating five to seven servings of fruits and vegetables daily provides the antioxidants that may retard damage to the brain’s DNA.
- Exercise: While aerobic exercise and strength training are beneficial, even just brisk walking for 15 minutes daily may lower Alzheimer’s risk, according to some studies. “You don’t have to become a triathlete,” Dr. Small says, “but when you get your heart pumping, you get more nutrients and oxygen to your brain cells.”
- Social engagement: Social interactions can both lower stress and stimulate the mind. Studies show that 10 minutes of a stimulating conversation is better for cognitive health than watching a TV show.
In summary, correlation is not causation. But remember, long before computer-assisted research, the empirical correlation between smoking and lung cancer was discovered, even though the physical mechanism had yet to be proved. So correlation can be meaningful, especially if the two outcomes being tested are logically related. It’s clear that exercise is logically related, as many studies link increased blood flow to the brain as a positive outcome for brain health in general.
Also remember, the law of large numbers applies here. Millions of Americans suffer Alzheimer’s already, and many millions more suffer lesser dementia. These huge numbers are bound to increase as the population continues to age, which means that empirically-based correlation studies, limited as they are, will grow in significance due to the benefit of longer and broader longitudinal studies.
We don’t have to wait for the “smoking gun” for Alzheimer’s to be discovered to statistically improve our chances of avoiding this horrendous disease!