Doctors find surprising twist in Alzheimer's study

Doctors say that, just like our body, our brain needs to be exercised. A new study shows that keeping the mind active can help keep Alzheimer's disease at bay, but there's a surprising twist.

Carmen Cox has a good memory, but says she is “aware that when you get older you lose your memory, and I would like to prevent it as much as possible.”

So the 71-year-old is taking classes at the University of California Los Angeles’ Semel Institute to help keep her mind sharp.

Whether it’s brain exercises, computer games or crossword puzzles, research shows seniors who keep their mind active can delay the onset of Alzheimer's disease. But a new study indicates that once Alzheimer’s hits, those brain exercises might do more harm than good.

Researchers followed two groups of patients. As expected, those who stayed mentally sharp were able to delay Alzheimer's. But once the disease took hold, patients in the active group saw their brain function deteriorate faster.

“Once people get dementia, it seemed to have the opposite effect, that more mental stimulation seemed to be worse,” said Dr. Gary Small with the UCLA Semel Institute.

Doctors say there is a silver lining – a slower onset and then a faster rate of decline means the patient will actually suffer from dementia for a shorter period of time.

Researchers speculate the brain is like a muscle. Exercise can make it stronger, but once it's compromised exercise may actually make it worse.

“Mental stimulation sped up brain decline at a certain point,” Small said.

Researchers at Rush University Medical Center in Chicago conducted the 12-year study which included more than 1,100 people.