Half of worldwide Alzheimer's cases are preventable, study suggests

Half of worldwide Alzheimer's disease cases can be prevented by making healthy lifestyle changes that are often associated with preventing other chronic health conditions, new research shows.

The biggest modifiable risk factors for preventing Alzheimer's among Americans, according to researchers at the San Francisco VA Medical Center, include physical inactivity, depression, smoking, mid-life hypertension, mid-life obesity, low education and diabetes. In analyzing data from other Alzheimer's studies with thousands of participants, lead researcher Deborah Barnes, Ph.D., found that together these risk factors are linked with 54% of Alzheimer's cases in the United States (2.9 million cases) and 51% of cases worldwide (17.2 million cases). Additionally, the number of Alzheimer's cases is expected to triple within the next 40 years, according to the study.

"What's exciting is that this suggests that some very simple lifestyle changes, such as increasing physical activity and quitting smoking, could have a tremendous impact on preventing Alzheimer's and other dementias in the United States and worldwide," Barnes said.

Barnes' findings were presented at the 2011 meeting of the Alzheimer's Association International Conference in Paris. The study was published online on July 19 in Lancet Neurology.