Q: My parents are worried about coming down with Alzheimer's. Is there anything they can do to prevent it? 

A: Tell them to keep up with their friends and family, make new friends and get out and about. Sound kind of folksy? Expecting advice that's more medical? Well, two prestigious institutions are making the case through research that staying socially active can help keep Alzheimer's at bay. 

The Harvard School of Public Health studied 2,800 people over age 65 years. Those who had monthly visual contact with three or more relatives or friends and yearly non-visual contact with 10 or more relatives or friends staved off mental decline much better than those who had little contact. People who had at least five social relationships and kept regular contact reduced their risk of Alzheimer's disease by almost 40 percent. 

It turns out that the mental decline we associate with aging isn't so much due to the death of nerve cells but rather the connections among them. Social interaction causes people to remain involved in the affairs of daily life and to continue to grow emotionally. It also requires making decisions. All of this interacting calls on your senses to process information and respond which, in turn, nurtures these neural connections in your brain. 

A few weeks ago, researchers at Rush University Medical Center's Alzheimer's Disease Center in Chicago offered further evidence that socially active older people are less likely to exhibit Alzheimer's symptoms. It's the first study of its kind that examined the relationship between social networks and Alzheimer's disease pathology. The Rush researchers studied their elderly participant's social activities up until their death and were given permission to perform autopsies of their brains. 

What did they find? Seniors with larger social networks exhibited fewer effects from the markers of Alzheimer's disease -- tangles and plaques -- than those with smaller social networks. So, even if participants had symptoms of Alzheimer's disease indicated by their brain autopsies, you wouldn't know it while they were alive. The researchers gave them 21 cognitive performance tests every year and collected information about their social networks. None of the 89 people autopsied indicated any signs of dementia when they signed up for the study. Over one thousand people are part of this ongoing research project. 

The lead researcher, Dr. David Bennett, explains the findings this way: "Many elderly people who have the tangles and plaques associated with Alzheimer's disease don't clinically experience cognitive impairment or dementia. Our findings suggest that social networks are related to something that offers a 'protective reserve' capacity that spares them the clinical manifestations of Alzheimer's disease." In other words, healthy and frequent interactions with friends and family build your brain's protective reserve against Alzheimer's. 

How did researchers measure social networks? They looked at the number of a participant's children and how often they see them monthly; the number of relatives and friends to whom they feel close, talk to, confide in and would call upon for help and specify how often they see them monthly. Their social network was the number of these individuals seen at least once per month; spouses were not included. The larger the size of this network then the greater their protective reserve to ward off the effects of tangles and plaques. Semantic memory, which houses our knowledge about the world and language, seems to benefit most from staying socially active. 

Watching television as a means of social interaction, in no way replicates the benefit of live interaction. So, watching Oprah doesn't count. If your parents are no longer driving or find it too much of a hassle to drive, help them make arrangements to remain socially involved with family and friends. If you live out of town and are worried about them being alone and isolated, think of hiring a nonmedical senior care service to drop by once or twice a week to prepare and have lunch with your parent, take them out and even play their favorite games with them like card games or checkers. Get families and friends to call every week and do something that's the greatest gift of all -- visit.