3 predictors of future memory loss: do you have any of them?

By Deborah Kotz, Globe Staff

If your doctor had a crystal ball that could predict whether you’d become senile in old age, would you want to know? Perhaps, if you could actually do something to prevent it. A growing body of research indicates that certain lifestyle factors may be associated with an increased or decreased risk of developing dementia due to Alzheimer’s disease or strokes.

As I’ve previously reported, physical activity, quitting smoking, and avoiding diabetes can all help lower Alzheimer’s risk. So, too, can engaging in intellectual pursuits such as reading. Three new studies released by the American Academy of Neurology this week have found some surprising factors -- such as sleep habits and calorie consumption -- that may also play a role in predicting how much memory loss we’ll experience in old age.

None of the studies prove that these factors actually cause dementia; they merely make associations that have led researchers to conclude that they may increase a person’s risk. As science adds more pieces to the aging brain puzzle, the case is getting stronger for eating right and staying active before hitting your senior years.

1. Walking slowly. A Boston Medical Center study released yesterday, which followed more than 2,400 volunteers in their 50s and 60s for 11 years, found that those who had the fastest walking pace were the least likely to develop severe memory loss at the end of the study. Those with the strongest hand grip at the start of the study also had a lower risk of developing dementia compared with those with weaker grips.

“These are just markers that predicted risk,” said study author Dr. Erica Camargo, a neurologist at Boston Medical Center. It could be that those who are weaker walkers and grippers are already on the road to Alzheimer’s. “But,” she added, “other studies have shown that those who are physically fit have less cardiovascular disease, which protects them from white matter changes in the brain that lead to dementia.”

2. Excess calorie consumption. Results from the Mayo Clinic Study of Aging compared the calorie consumption of more than 1,000 healthy volunteers ages 70 to 89 with no memory loss and found that it was, on average, much lower than that of 163 age-matched patients with mild cognitive impairment.

Consuming more than 2,150 calories a day doubled the odds of having some memory loss. The researchers said the study needs to be confirmed before making any dietary recommendations, but exercising some portion control certainly can’t hurt your waistline.

3. Interrupted sleep. Sleeping poorly could be a sign of future dementia, but it’s still not known whether improving sleep habits can actually ward off memory loss. A Washington University study released Tuesday found that those who woke up frequently during the night -- more than five times an hour -- were more likely to have abnormal markers in their spinal fluid and imaging scans that indicated early Alzheimer’s disease.

While both the deep sleepers and the easily aroused participants in the study spent eight hours in bed, those that woke frequently only slept for an average of 6.5 hours a night.

Deborah Kotz can be reached at dkotz@globe.com. Follow her on Twitter @debkotz2.