We all want to maintain peak mental function throughout our lives, particularly as we age. And there are few scenarios more frightening to confront than the onset of dementia.
Dementia is not a specific disease, but rather an umbrella term to describe symptoms related to cognitive decline. Alzheimer’s disease—a brain disorder that over time leads to worsening memory, thinking and the ability to function—is the most common form of dementia, accounting for 60 to 80 percent of cases. An estimated 5.7 million Americans have Alzheimer’s. The causes of Alzheimer’s are not fully understood, but the risk is partly determined by genes.
Gary Small, MD, director of the UCLA Longevity Center and professor of psychiatry and biobehavioral sciences at UCLA in Los Angeles, California, is an expert in the fields of age-related memory decline and dementia. He wants people to know that, while there is no cure for Alzheimer's disease, genetics does not explain the entire problem.
“In fact,” he says, “for many people, non-genetic factors could be even more important.”
The second most common form of dementia, accounting for an estimated 10 percent of cases, is vascular dementia, which is caused by strokes or other conditions that impede blood flow to the brain. Risk factors for vascular dementia mirror those of heart disease and stroke and include diabetes, high blood pressure and high cholesterol.
While there’s no single way to delay or prevent dementia, there are actions that—taken together—may help reduce your risk.
“Understanding what you can do to protect your brain as best as you can makes sense,” Dr. Small says. “And the sooner we start doing it, the greater the impact.”
Addressing risk factors for dementia
According to a study published in The Lancet in 2017, about 35 percent of dementia cases are due to risk factors we may have some control over.
These include:
- Low levels of education
- High blood pressure and obesity in midlife
- Hearing loss
- Depression later in life
- Diabetes
- Physical inactivity
- Smoking
- Social isolation
Taking steps to address these lifestyle factors may help reduce your chances of developing dementia.
Improve your cardiovascular health: Since the brain is highly vascular—in other words, filled with many blood vessels—what benefits the cardiovascular system also benefits the brain. Managing high blood pressure, maintaining a healthy weight, quitting smoking and keeping diabetes under control all benefit your heart and your brain.
Eating a healthy diet may help, too, by improving your heart health. Some research suggests that the MIND Diet—an eating regimen that combines features of the Mediterranean diet and the DASH Diet to control blood pressure—may help lower dementia risk.
The research into whether exercise directly affects dementia risk is unclear, but staying fit boosts heart health and may in turn benefit your brain.
“I tell people if you have a choice between a crossword or a treadmill, take the treadmill,” says Small. And if you can take your workout outside, all the better.
“There's data that shows walking outside is better for your brain health than exercising inside,” says Small. “That may have to do with more mental stimulation. When you’re outdoors, you simply see more things as you walk by.”
Manage your stress and stay social: “We know that being stressed out is bad for your brain,” says Small, so it makes sense that lowering your stress as much as you can may be part of an overall brain-healthy strategy.
“Socializing with like-minded and empathic people is really important,” says Small. “I like to say the triple threat against Alzheimer's disease is taking a walk with a friend: The back and forth interaction of the conversation stimulates the mind. If the person's empathic, it will lower your stress. And the physical exercise will boost your brain cells.”
Protect your hearing: Some research suggests that people with hearing loss have a higher risk for dementia. It’s unclear why this is so, but Small says it could be due to something that contributes to both conditions or it could be related to the effects of hearing loss.
“If someone has hearing impairment, they become more withdrawn socially and receive less intellectual input,” he explains.
Get your rest: It’s unclear whether sleep disturbances may be a risk factor for cognitive decline or a consequence of it. But the link as currently understood is a helpful reminder of the importance of maintaining good sleep habits as you age.
Treat depression: Studies suggest that depression—particularly late in life—is associated with an increased risk of dementia. If you notice any signs of depression, seek help from your healthcare provider and be sure to follow your treatment plan.
Why cognitive reserve is important
It’s believed that accumulating learning may help blunt the effects of cognitive decline if and when it does occur. This is known as building “cognitive reserve.”
“Basically,” says Small, “it means that if you're smarter, the symptoms of dementia will not be as apparent early on.”
A study published in 2014 in JAMA Neurology that looked at 1,995 people age 70 to 89 without dementia found that a lifetime of intellectual enrichment—through education and occupation—was associated with a delay in the onset of cognitive impairment by roughly 8.7 years for men and 8.8 years for women who had a genetic predisposition toward Alzheimer’s disease.
“It may be that people who are smart to begin with end up going to college,” explains Small, and those people have a more robust brain that’s resistant to the effects of cognitive decline.
He also speculates that it may not even be the mental stimulation of college that has a beneficial effect on preserving cognitive function, but rather that people who go to college tend to learn the type of healthy habits (mentioned above) that may be brain-protective.
Staying stimulated as you age
The JAMA Neurology study also suggested there may be a benefit to keeping up with a high level of mentally stimulating activities in mid-and later-life. In fact, people with lower lifetime education levels benefited more from these intellectual activities than did folks who had higher levels of education to begin with.
In other words, even if you didn’t have advanced education or a career that involved intellectual activity, you may still be able to compensate for the effects of cognitive decline by engaging your brain later in life.
According to the research, a high level of engagement meant doing cognitively stimulating activities at least three times a week. That might include reading books and magazines, doing puzzles and crosswords, playing games and music, using computers or participating in crafts, art and social activities.
“This is an observation that has been made for some time and replicated in different kinds of studies,” Small says. “That is, that there is an association between mental activity, stimulating mental pursuits and better cognitive health and lower risk for dementia.”
Although there’s no guarantee you can replicate the results laid out in this or other studies, according to Small, it is worth challenging your brain with activities that engage your interest while remaining fun.
“I tell people you want to train and not strain your brain,” Small says. “Look for stimulating activities that are not too easy, because then it will be boring, and not too difficult because then it will be stressful.”
Research is not yet definitive
It’s important to recognize that some of your risk for dementia is dictated by factors outside of your control, such as your age, family history, genetics and the unique circumstances of your life. And there is no single method for preventing or slowing cognitive decline that will work for everyone.
“When we’re talking about studies, we’re looking at specific populations, so what may be true for some people may not hold true for everyone,” Small explains.
And while some techniques of mental stimulation have shown promise in the short term for improving cognition, Small explains, “We don't have a test for an individual to say, ‘If you do so many crossword puzzles for the rest of your life, you're going to delay the onset of dementia by so many months or years.’”
For people interested in doing what they can to foster and maintain brain health for the present and into the future, a holistic approach that includes adopting healthy habits, building social connectedness and engaging in intellectual stimulation is the best bet we have.
