A Beautiful Mind

Scrapbooks. Photo albums. Memory boxes. Those are just a few ways we try to preserve memories. But what are you doing to preserve your most precious memories--the ones inside your head? Loss of memory, brought on by dementia, is something most of us don't want to think about. Women don't like hearing that we're more vulnerable to dementia because we tend to live longer than men. But about half of us who reach the age of 85 will have symptoms of it. Even if we escape it ourselves, there's a good chance we'll be caring for someone else who has it.

If those facts weren't bad enough, consider this: As demographics shift and people live longer, the projected prevalence of Alzheimer's is expected to quadruple by 2047, says Dr. Kristine Yaffe, an Alzheimer's expert at the University of California at San Francisco. To give a sense of the associated cost, Yaffe recently told a conference on women's health that by delaying nursing home placements of Alzheimer's patients by just one month, the country could save $5 billion a month.

It's tempting to believe that this is a worry we can perpetually put off till tomorrow. After all, dementia before age 70 is rare. The fact that there's no cure probably encourages a lot of us not to think about it at all. But there is growing evidence that your health at midlife is more predictive of your future risk of dementia than your health during your senior years. That makes sense, since the first seeds of dementia begin to take root in your brain about 20 to 30 years before you show symptoms.

The good news? There are steps you can take in your 40s or 50s that may lower your risk of developing dementia in your 70s or 80s. New research has indicated that many of the habits that help keep your heart healthy are also good for your brain. That's because a healthy vascular system seems to be a key component of both. Gerontologists like Dr. Laurel Coleman, a member of the Alzheimer's Association national board, used to spend a lot of time trying to determine if their patients had Alzheimer's or vascular dementia--but many no longer bother. They believe that most people who have dementia probably have some of both.

In practical terms, that means that if you work hard to keep your blood pressure in check and your cholesterol levels and weight under control, you'll lower your risk of cardiovascular disease and dementia at the same time--a kind of a two--for--one special. Researchers from the Karolinska Institute in Stockholm, following 1,449 seniors over the course of 21 years, recently reported that those who had hypertension at midlife were twice as likely to develop dementia decades later as those who didn't. Those who were obese (with a body mass index of 30 or higher) at midlife also had double the risk of those who weren't. The same was true of those with high cholesterol counts. All these risks were cumulative--so people who had two of these three problems had four times the risk of those who had none. Those with all three had six times the risk.

Similar correlations between midlife diabetes and dementia were published in 2004 by researchers at Mt. Sinai School of Medicine who'd reviewed the medical records of 1,892 Israeli heart study participants who had been followed since the early 1960s. The connection isn't completely clear yet, but one theory is that uncontrolled diabetes increases your risk of brain damage, making you more vulnerable to dementia.

Smoking isn't good for anything, so it's probably no surprise that smoking at midlife isn't good for your brain or your heart either. The good news is that quitting in midlife probably reduces your risk, according to results from the Honolulu--Asia Aging Study.

Another disease that's highly correlated with dementia is depression, according to a meta--analysis of 13 studies, published in 2001. It's not clear what the cause--and--effect relationship is between the two, but if you have one, your chances of having the other increase. A link has also been established between depression and increased risk of heart disease, says the National Institute of Mental Health.

"A lot of things are beginning to add up, about the relationship between Alzheimer's and vascular disease," says Coleman, who has a geriatrics practice in Augusta, Maine. "The problem is that a lot of people just want to take a pill. They don't want to hear that they have to watch their diet and exercise, not smoke and watch their blood pressure. Those things are harder than taking a pill."

Unfortunately, there is no magic pill that offers any real protection. While vitamin E, vitamin C, ginkgo biloba and antioxidants were touted at different times as having the potential to be dementia--fighting superheroes, when they were put to the test, they didn't have enough of the right stuff. (Vitamin E and ginkgo biloba may slow the progress of the disease for several months, but neither will protect you from getting it.) Researchers remain intrigued by folate, B12 and B6 because of their role in recycling homocysteine, a byproduct of protein breakdown that can clog your arteries. Some believe that deficiencies of these substances may make you more vulnerable to dementia, but more research is needed. Ultimately, Yaffe says, the hope is that researchers will be able to develop something that will pulverize the amyloid plaques that clog up the brain and characterize Alzheimer's, but that's not on the horizon yet. "We know more than we did five years ago, and we hope we'll know more in the next five years that can be used in a practical way," says Dr. Victor Henderson, a dementia researcher at Stanford University.

In the meantime, Coleman says, the link between dementia and heart disease should be the "tipping point" that prompts a lot more people to make positive changes in their lifestyle--even if they hate exercise and love their cheeseburgers. "Understanding that heart disease increases your sensitivity to dementia should be the thing that moves them off the dime, gets them to do what they need to do," she says. While everyone knows that you shouldn't smoke and should exercise and watch your diet, what's new is their relationship to dementia. "We need to keep bringing this up because none of these changes are risky to your health," she says. "It's already well proven stuff for heart disease and stroke, and now it's strongly implicated in lowering your risk of dementia. For some people, this will be the thing that moves them."

Right around now, you may be asking: What about genetics? Aren't some people predestined to get this disease no matter what they do? Some may be. But the interplay between genetics and lifestyle when it comes to Alzheimer's is more robust than you might suppose, as Dr. David Snowdon discovered during his famous "Nun Study," which looked at the prevalence of Alzheimer's in 678 nuns between the ages of 75 and 106 over the course of several decades. One thing that made his work remarkable was that he autopsied the brain of every participant upon her death, whether she exhibited any symptoms of Alzheimer's or not. He was stunned to find that some of the nuns who seemed to have the most severe symptoms of Alzheimer's had very few brain plaques and tangles (neurofibril masses that tend to develop inside the brain cells of those with Alzheimer's). Others whose brains contained masses of plaques and tangles had never exhibited any outward sign of the disease while they were alive. The thing that made the difference, he concluded, was the state of their vascular systems. The healthy group "never experienced a stroke or diabetes or what is often called "hardening of the arteries'," Coleman said. "Because they had these very healthy vascular systems, their brains were able to hold off Alzheimer's better."

There are no guarantees that even if you do everything perfectly, you'll never get dementia. But you may be able to boost your odds, which is something to remember the next time you hear French fries and a cheeseburger calling your name.