No one yet knows how many cases of Alzheimer's can be prevented by healthier living. But without treatments to change the course of the disease, researchers believe prevention may be key to avoiding its memory and quality of life challenges.
Taking preventive measures against dementia involves common sense, healthy activities — exercising regularly, eating well, sleeping enough — as well as keeping your brain active and challenged.
Precise prescriptions aren't possible yet, but new evidence for prevention came out this week at the Alzheimer's Association International Conference in Boston, said Steven Arnold, director of the University of Pennsylvania's Penn Memory Center.
"We're understanding the course of the development of Alzheimer's disease much better now," he said, adding that dementia probably takes decades to develop.
Genetics drives vulnerability to Alzheimer's, and there are an unlucky few who carry a single gene mutation that dooms them to the disease. For everyone else, the way they live earlier in life can help determine how agile their brain remains, and for how long.
"I'm 55 years old," Arnold said. "What I do now is going to determine whether I am demented in my old age or not."
Even in early childhood, we may be able to lay the groundwork for a healthy brain decades later.
Studies consistently find that people with more education are less likely to develop Alzheimer's. "Sometimes I think the best way to prevent Alzheimer's is fully fund early childhood education," said Arnold, a psychiatrist and neurologist.
Other research has linked binge-drinking early in life to an increased risk of Alzheimer's.
Part of our understanding of Alzheimer's, Arnold said, is a growing recognition that the disease is closely related to other conditions, like diabetes and heart disease. Keep those at bay through a healthy lifestyle, and you may be able to reduce your risk of dementia, he said.
Arnold said he now manages his middle-aged patients' cholesterol, blood pressure, obesity and sugar levels much more aggressively than he used to, to make sure that their blood vessels are feeding enough blood to their brain and that they avoid diabetes, which can make brain cells more vulnerable to damage.
"If you can manage these well in your 50s, you can probably reduce your risk of developing Alzheimer's, some people estimate by as much as 50%," he said. "Or at least delay the onset of Alzheimer's by a couple of years" — pushing memory loss into your 80s or beyond.
Even after symptoms of dementia have begun, evidence suggests that regular aerobic exercise can improve quality of life, said Heather Snyder, director of medical and scientific operations for the Alzheimer's Association. "It's beneficial whenever you start."
Here are some specific, evidence-based recommendations from Snyder, Arnold and others:
Aerobic activity three times a week for 40 minutes is strongly supported by research. That's not taking a stroll looking at shop windows, but actually breaking a sweat and elevating your heart rate.
The symptoms of sleep disorders can be similar to dementia, so it's important to identify and address sleep problems, said Alvaro Pascual-Leone, a neurologist at Harvard Medical School and Beth Israel Deaconess Medical Center. Medications, late-night exercise and alcohol can also interfere with sleep quality and length.
Typically, adults should get between seven and nine hours of sleep daily, he said.
Snyder, Arnold and Pascual-Leone all recommend a heart-healthy Mediterranean diet, rich in plant-based foods such as vegetables, fruits, legumes and whole grains, with healthy fats such as olive oil instead of butter, and a minimal amount of processed foods and sweets.
Keeping mentally active:
Crossword puzzles aren't enough to challenge your brain, Pascual-Leone said, if you're already a regular puzzle doer. Instead, pick up new skills like learning to dance or paint or do math problems — something that's challenging and a little outside your comfort zone, he said.
"It's not about coasting into old age with the activities you like to do, but encountering the kinds of challenges our kids go through" when they study subjects as varied as math, history and foreign language, Pascual-Leone said.
Online brain-training programs, like Lumosity by Lumos Labs and BrainHQ from Posit Science, can be helpful if done frequently enough, said Pascual-Leone who earlier this month opened a brain fitness center at Beth Israel Deaconess Medical Center in Boston to engage patients in brain training and other lifestyle improvements.
Some stress is clearly good for the brain, but too much can be toxic. There's growing evidence that things like mindfulness meditation and yoga are good for the brain, Arnold said.