You can reduce your risk of dementia. Here's how to get started

One key to healthy aging is to keep our minds sharp.

And some of the best strategies to fend off dementia, stroke and even late-life depression come down to our daily habits.

"You can substantially reduce your risk through the lifestyle choices you make," says Dr. Jonathan Rosand, a neurologist and co-founder of the McCance Center for Brain Health at Massachusetts General Hospital.

Rosand and his collaborators have developed a way to gauge and track brain health with a 21 point scale called the brain care score. The score helps people understand the importance of daily habits — such as sleep, diet and exercise. (You can calculate your score in about five minutes.)

"All of us have a fair amount of control," Rosand says.

About 40% of dementia cases could be prevented or delayed by addressing 14 modifiable risk factors, according to a Lancet commission report. And even people who have genetic risk factors can benefit. A question Rosand is often asked is "Doctor, what can I do so I don't get dementia like my father or brother or sister?"

Ruth Bernstein knows the anxiety. "We watched my grandma be robbed of her identity" from Alzheimer's, Bernstein says. And now the same thing is happening to her mom. "It's truly devastating," she says.

As the mom of two kids, Bernstein wants to do all she can to protect her brain, and calculating her brain care score helped her understand the many lifestyle tweaks she can make. "It's been super helpful," Bernstein says. "It's really motivated me because I understand how it can all add up."

Bernstein finds herself going through a checklist of items on the score: "Have I got my steps in? How's my sleep? Am I managing my stress? At a recent social gathering she drank a glass of wine, but turned down a second. Limiting alcohol to fewer than four drinks a week leads to a higher score.

To calculate your brain care score, you rate yourself on 12 different risk factors ranging from diet, alcohol consumption, smoking, sleep and the amount of exercise you get. Your blood pressure, blood sugar, cholesterol and body mass index are also incorporated. Social and emotional factors are woven in as well, including sense of purpose, stress management and social connections. Each response is given a point value, and the higher your score the better.

Several studies show that a high brain care score is linked to a significantly lower risk of disease. For instance, a study published in Frontiers in Psychiatry, found that each five-point increase in a brain care score was associated with a 33% lower risk of late-life depression and a 27% lower composite risk of dementia, stroke and depression.

"What was surprising to us was just how powerful it was," says Dr. Kevin Sheth, the director of the Center for Brain and Mind Health at Yale University and a co-author of the recent study. "To have an effect on that order of magnitude is quite large," he says.

A follow-up study published this month in the journal Neurology, which stratified participants by genetic risk, found that a higher score was linked to a lower risk of brain disease including dementia and stroke, even among people who had inherited an increased genetic risk for these diseases.

"The good news is that if you engage in healthy behaviors, you are much more protected against dementia than if you do not do those things," says study author Dr. Christopher Anderson, chief of the Division of Stroke and Cerebrovascular Diseases at Brigham and Women's Hospital.

"The idea is to get away from the idea of genetic determinism," where people feel like there's nothing they can do about their risk, and instead emphasize how powerful healthy choices can be, Anderson says.

Yale's Kevin Sheth says the brain score research has had an impact on his own habits. He's swapped sugary desserts for fruit at some meals and added more leafy greens and healthy fats to his diet. "I'm motivated because I know the data," he says.

Another way to improve your brain care score is to manage chronic conditions, like high blood pressure and diabetes. Lifestyle choices can help, but often people need medication. "If we were able to eliminate high blood pressure," which is just one component of the score, "we could [reduce] dementia by orders of magnitude," Sheth says. He says it's also important to recognize the challenges people may face in changing their behaviors. When it comes to eating well, not everyone can afford to buy lots of fresh fruits and vegetables.

Rosand and Sheth say people shouldn't view the brain care score as a test that you can fail. "Very few people can have a perfect score," Sheth says. "The goal is to have the best score that you can and monitor it over time."

There's a lot of overlap between the score and the American Heart Association's Life's Essential 8, which includes key measures to improve heart health. This makes sense, says Dr. Helen Lavretsky, a geriatric integrative psychiatrist at UCLA, because it's increasingly clear that many of the things that are good for our hearts are also good for our brains.

And it's never too soon to focus on prevention. "The earlier you start, the better," Lavretsky says.

This story was edited by Jane Greenhalgh.