As a country, we spend a lot of time, energy, and money on understanding Alzheimer’s and treating it, but relatively little on preventing it to begin with, says Jin-Tai Yu, MD, PhD, of the University of California–San Francisco’s Memory and Aging Center and department of neurology. Which is why a number of studies recently have tried to estimate the enormous impact prevention efforts could have. In the latest report to examine these modifiable risk factors, Yu and colleagues identified nine things that contribute to about 66% of Alzheimer’s cases around the globe. With data from more than 323 previous papers reporting on more than 5,000 people, theirs is a pretty powerful argument in favor of taking steps to reduce our risk of the disease. Because of the observational nature of these types of studies (no one is examining education levels by sending a group of people to college and not letting another group go, then comparing how many in each group develop dementia, for example), we can’t definitively say that changing your routine is a brain-health guarantee, says Demetrius Maraganore, MD, medical director of the NorthShore Neurological Institute and chair of the neurology department at NorthShore University HealthSystem in Chicago. But while we wait for future research on the nitty-gritty details, at least it’s pretty certain that making a few healthy changes won’t hurt, he says. What’s likely most powerful, says Heather Snyder, PhD, director of medical and scientific operations at the Alzheimer’s Association, is making a handful of these changes, rather than just one. “Eating a balanced diet alone probably isn’t going to reduce your cognitive decline risk later in life,” she says. “A combination of all these different brain-healthy lifestyle choices will keep you as healthy as you can be.” (Discover the 5 best foods for your brain and other cutting-edge natural tips in Prevention’s Ageless Brain.) So where should you start? Here are the 9 modifiable risk factors for Alzheimer’s that Yu’s study identified, plus what you can do to help yourself stay healthy.
Obesity, particularly at midlife
Why it ups your risk: We know we don’t have to convince you that obesity’s bad news for your overall health. When it comes to memory protection, Maraganore says, being overweight might be a sign your diet’s higher in sugar and processed foods than something like a brain-friendly Mediterranean diet, which can reduce Alzheimer’s risk by up to 50%. Maybe obesity is a sign of a sedentary lifestyle, considering people well into their 70s can still experience growth in memory areas of the brain if they start working out, he says. It’s also possible there’s something independently damaging about obesity that researchers haven’t pinpointed yet, he says. What to do about it: Get yourself to a healthy weight and stay there, plain and simple (easier said than done, we know). While being underweight won’t do you any favors (more on that below), there’s simply no reason you shouldn’t aim for “normal” at any age, Maraganore says.
Frailty
Why it ups your risk: On the other end of the spectrum, it’s not helpful to be undernourished, either, although researchers don’t totally understand why. It’s possible that Alzheimer’s and frailty stem from a common cause; frailty may be a physical symptom of Alzheimer’s that appears before memory problems are noticeable. What to do about it: If that’s the case, Maraganore says, avoiding frailty isn’t as simple as eating healthfully or getting enough exercise (although if you’re not doing those things, hop to it). If a person is growing more frail because he or she is forgetting to eat or is unable to take good care of themselves, dementia may have already progressed to a certain extent. But frailty might also be a sign other confounding factors are present, he says: Maybe a person is struggling with finances or not receiving strong social support and therefore unable to eat well.
Carotid artery disease
Why it ups your risk: When plaque builds up inside the carotid arteries, which run along the sides of your neck, blood has a harder time reaching your brain. Restricted blood flow is pretty obviously problematic anywhere in the body, but in the carotid arteries it can mean damage and death to crucial brain cells. What to do about it: In serious cases, a doctor may need to perform a medical procedure to open blocked carotid arteries. For others, anti-clotting meds might help clear blockages and prevent strokes. But many people can control carotid artery disease with the classic arsenal of healthy habits: eating nutritiously, keeping cholesterol and blood pressure in check, hitting the gym, and quitting smoking.
High blood pressure
Why it ups your risk: Like carotid artery disease, high blood pressure can damage blood vessels that in turn affect the flow of blood to the brain. What to do about it: Get your BP in check, Maraganore says. About 70 million Americans have hypertension, but only about half of those folks get their high blood pressure under control. The standard advice is to aim to lower high blood pressure to under 140/90. The National Institutes of Health is currently studying whether getting your blood pressure even lower might significantly improve brain health. (Here are 13 power foods that lower blood pressure naturally.)
Lower levels of education
Why it ups your risk: “The brain is like a muscle,” Maraganore says. “If you don’t use it, you lose it.” But unlike your abs, which you can tighten back up when you start to feel them slipping, if you do start to lose some brainpower, you might never get it back. Learning forges new connections in our brains, he says. Gaining new knowledge forces the brain to maintain those connections. “If you’re not using your brain, you’re more vulnerable to processes that almost invariably occur with brain aging.” What to do about it: Education is the modifiable factor that accounts for the most control we have over Alzheimer’s worldwide, Maraganore says. (In the US alone, where we tend to reach a higher level of education in general than people in many developing countries, it’s exercise.) And of course, the more education you get, the lower your Alzheimer’s risk. Few of us can drop everything and go back to grad school, but there are lower-commitment ways to keep learning, like taking a dance class, teaching yourself guitar, or finally picking up a new language. (Try these 7 brain games to make you smarter.)
Depression
Why it ups your risk: While a number of studies have linked depression to an increased risk of dementia, it’s not entirely clear what’s happening in the depressed brain to raise the risk, Maraganore says. It could be that the withdrawal and social isolation sometimes seen with depression results in the brain not being challenged enough, he says. Or maybe changes in the brain that are linked to Alzheimer’s are actually causing depression symptoms, Snyder says. What to do about it: It’s all about managing symptoms, Snyder says, whether that means therapy, medication, lifestyle changes, or a combination of some or all of those techniques. The goal, she says, is to enable a person with depression to stay socially and physically active. If you’re hesitant to speak up about emotional or mental health concerns, consider it an important step within the larger context of keeping your entire brain healthy, she says.
High levels of homocysteine
Why it ups your risk: Homocysteine is an amino acid made during the process of breaking down protein. In high levels, usually found among people who eat a lot of red meat, it seems to be linked to inflammation, which may in turn make you more vulnerable to cognitive decline, Snyder says. What to do about it: Adopt the occasional meatless Monday, or even consider skipping meat more than once a week. Eating more leafy greens, fruits, and whole grains seems to help lower homocysteine levels. Here’s an easy way to make crispy pan-fried tofu for your meatless meal:
Diabetes
Why it ups your risk: At the most basic level, diabetes changes blood vessels and blood flow in the body, Snyder says, which in turn would alter blood flow to the brain. But more cutting-edge research suggests that perhaps Alzheimer’s results from insulin resistance in brain cells, or so-called type 3 diabetes, which can lead to a toxic protein buildup and brain cell death. What to do about it: Around 29 million Americans have type 2 diabetes. Of those, just more than a third, 35%, said their condition is “somewhat” controlled and 5% said it’s “not at all” controlled in a recent poll from Harris Interactive and HealthDay. Even though the constant surveillance might sound like a drag, avoiding diabetes complications is ultra important—and depends on you working with a doctor to manage the condition, Snyder says.
Smoking
Why it ups your risk: On top of all the other perils of a smoking habit, tobacco can also hurt your memory: The damage smoking does to blood vessels can lead to the same kind of plaque buildup and blood flow restrictions to the brain as seen in people with heart problems. What to do about it: If you still haven’t kicked the habit, add Alzheimer’s to the (long) list of reasons to quit, stat. It’s never too late.
