New study finds one-third of Alzheimer's cases are preventable

Scientists have linked a new protein to Alzheimer's disease, different from the amyloid and tau that make up the sticky brain plaques and tangles long known to be its hallmarks.

The study, done in Finland, doesn't point to any one thing people can do to prevent memory loss. Instead, it's a cocktail, the researchers told a meeting of Alzheimer's experts.

 "It's the first time we have been able to give people a kind of recipe for what is useful," said Maria Carrillo, vice president of Medical & Scientific Relations at the Alzheimer's Association.

The researchers examined the brains of 342 people who'd been diagnosed with Alzheimer's disease through autopsies. (Alzheimer's cannot be definitively confirmed when patients are alive.) Almost 200 of them had TDP-43, according to the study.

"This is some good news," said Dean Hartley, director of science initiatives for the nonprofit Alzheimer's Association. The studies were scheduled to be presented at this week's Alzheimer's Association International Conference, being held in Copenhagen, Denmark.

Several studies have linked good heart health to lower risk of developing Alzheimer's. Oxygen to the brain is critical to staving off dementia. 

"What's good for the heart is also good for the brain," Hartley said, and researchers are also attributing the lower levels to better awareness about lowering Alzheimer's risk as well as improved education about health and lifestyle factors that impact health.

It's long been believed that activity, mental and physical, is crucial to avoiding Alzheimer's disease and other dementia ailments.

"For an individual, the actual risk of dementia seems to have declined," probably due to more education and control of health factors such as cholesterol and blood pressure, said Dr. Kenneth Langa, a University of Michigan expert on aging.