One-Third of Seniors Have Mental Decline

The findings underscore the need for families to be on the lookout for signs that their loved ones are starting to lose their sharpness, she said.

"From a personal perspective, we need to be more aware that our parents, our grandparents, our aunts and uncles may experience mild changes that may make them more vulnerable to being taken advantage of by scams," Plassman said. "They may need more support and assistance in making more complicated decisions."

Doctors also need to be aware of the scope of the problem, she said.

"Some patients may not understand all of their instructions or may not be able to remember all the instructions given," she added. "The treating professional might consider writing instructions down so the patients can refer to them later."

For individuals experiencing or worried about developing these problems, research indicates that the best thing to do is to remain physically and mentally active, Plassman said.

"Our current belief is that the things that are good for our hearts are good for our brains," she said. Lowering blood pressure and cholesterol and preventing diabetes appear to help stave off mental decline.

"Thus, there's been some research to suggest that exercise, both physical and cognitive exercise, is helpful," Plassman added, citing research suggesting that doing crossword puzzles, taking classes and participating in stimulating activities also may help.

"The data suggest they clearly are worth a try," she said.