Baby boomers aren't the only ones worried about their aging brains. More than 75 percent of millennials and Generation Xers fret about what will happen to their cognitive abilities as they grow older, according to a Harris Poll conducted in April for Aegis Living, an assisted-living and Alzheimer's disease care company.

Now, results from a trial in Finland—the first large, long-term study of its kind—suggest that healthy habits may offer some protection against cognitive impairment. The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) is an ongoing randomized controlled trial with more than 2,600 participants aged 60 to 77 who are considered to be at increased risk for dementia based on cardiovascular factors like blood pressure and cholesterol, as well as their performance on certain mental screening tests.

Healthy Intervention

Half of the group received an intensive intervention involving regular nutritional counseling and a tailored diet, an exercise program guided by physical therapists that included strength training one to three times a week and aerobic exercise two to five times a week, and mental skills training three times a week. The other half—the control group—received only regular health advice.

At the end of two years, all participants in the study had improved their performance on a standard set of mental tests, including specific tests of memory, executive function (complex aspects of thought such as planning, judgment, and problem solving), and cognitive processing speed. But the intervention group's mental performance was significantly better across the entire test, and particularly in executive functioning and processing speed, according to the results, which were published in June in The Lancet. The results did not, however, show any improvement in memory.

Sensible Results

The study's findings make perfect sense to Gary Small, MD, the Parlow-Solomon Professor on Aging and a professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA), director of the UCLA Longevity Center, and author of several books on the brain.

"Even though the study doesn't show whether or not this approach can actually delay the onset of dementia symptoms," Dr. Small says, "it is an encouraging demonstration that we can do things that can make a difference with cognitive functioning."

4 Habits to Remember

You don't need to be in an official trial or on a specialized program to adopt the habits of the participants in the FINGER study, says Dr. Small. Here's how to try them at home, after consulting with your doctor.

1. CLEAN UP YOUR DIET. Ditch the processed foods in favor of more fruits and vegetables. Plan meals that emphasize whole grains and lean protein and are low in saturated fats.
2. RAISE YOUR HEART RATE. Exercise for at least 30 minutes five times a week. Choose any activity you love that gets your heart rate up. Your target heart rate for exercise depends on your age and fitness level—at age 55, for example, the American Heart Association says the target heart rate for moderately intense exercise ranges from 83 to 140 beats per minute. Aim for the lower end of that range if you're just starting out.
3. LIFT WEIGHTS. Try to commit to at least two or three strength training sessions per week, using either free weights or machines.
4. TRAIN YOUR BRAIN. Stimulate your working memory, says Dr. Small. "That's the very short-term memory, where you hold information in your mind long enough to use it. Studies have found that training working memory improves the capacity to think logically and solve problems." Dr. Small recommends two working memory training games. "Dual N-Back" exercises, a simultaneous test of visual and auditory memory, involve matching pictures and sounds. A free, open-source version of the game is available. And a brain training computer game called "Brain Fitness" by Dakim, Inc. was found to improve brain function in older adults in a study published in the American Journal of Geriatric Psychiatry in 2013.