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/ Source: TODAY
By Linda Carroll

It’s long been known that marriage seems to protect the heart and contribute to longevity. Now a new study shows that being married may also help protect the brain.

British researchers found that compared to married people, lifelong singles were at a 42 percent greater risk of developing dementia, according to the study published online in the Journal of Neurology, Neurosurgery & Psychiatry.

The bottom line is that “we can all make a difference to our risk of dementia by maximizing our physical health through eating healthily, taking exercise and reducing smoking and alcohol, as well as keeping an active mind by education and social activities,” said the study’s lead author, Dr. Andrew Sommerlad, a psychiatrist and researcher at University College London.

To put singles’ increased risk in perspective, it’s important to see it in the context of other risk factors, said Dr. Gary Small, director of the Longevity Center at the University of California, Los Angeles, and author of “Two Weeks to a Younger Brain.” Small is not affiliated with the new study.

“We’re hearing more and more that a daily workout not only protects the heart, but also the brain,” Small said. “That 42 percent is comparable to the impact of inactivity and smoking.”

The researchers combined data from 15 earlier studies that looked at the potential role of marital status on dementia risk. Their meta-analysis involved data from more than 800,000 people from Europe, North and South America, and Asia.

Widowed people also experienced an increased risk of dementia over marrieds — at 20 percent, not as much as lifelong singles. There was no increase in risk found among divorced folks, but Sommerlad suspects that is because there wasn’t enough data from this group.

The researchers suspect that widows and widowers are at higher risk because bereavement is likely to boost stress levels, which have been associated with impaired nerve signaling and cognitive abilities.

While the article didn’t specify which conditions had caused dementia in study volunteers, which is diagnosed when a person has memory or other cognitive declines that interfere with a person’s independence, most cases are related to Alzheimer’s disease, Small said.

How does marriage protect the brain?

The researchers don’t know exactly, but they’ve got theories.

“We do not think that marriage itself reduces people’s risk of dementia,” Sommerlad said. “Our research suggests that the protective effect is linked to the generally healthier lifestyle and having more lifelong social contact which tends to be seen in married people.”

That makes sense to James Becker, a professor of psychiatry, neurology and psychology at the University of Pittsburgh and associate director of the university’s Alzheimer’s Disease Research Center.

“There does seem to be something associated with being married relative to not being married,” Becker said. “Maybe it has something to do with physical health or a background level of happiness or contentedness. Or it could be related to sociability that comes with marriage.”

Also, a spouse may make sure their loved one gets to the doctor or gets help for chronic conditions like high cholesterol or hypertension.

So, even if someone isn't married, being extra vigilant about overall health could be protective.