Dementia Cuts Cancer Risk by 30 Pct

Dementia may cut the risk of cancer, according to a new study.

Researchers found that seniors who are starting to have memory and thinking problems, but do not yet have dementia, are less likely to die of cancer compared to those who have no memory and thinking problems.

"Studies have shown that people with Alzheimer's disease are less likely to develop cancer, but we don't know the reason for that link," study author Julián Benito-León, MD, PhD, of University Hospital 12 of October in Madrid, Spain, said in a statement. "One possibility is that cancer is under diagnosed in people with dementia, possibly because they are less likely to mention their symptoms or caregivers and doctors are focused on the problems caused by dementia. The current study helps us discount that theory."

The latest study involved 2,627 people older than 65 in Spain who did not have dementia at the beginning of the study. Participants took memory and thinking tests as the start of the study and against three years later. The participants were followed for an average of 13 years. They were divided into three groups: people who experienced the greatest cognitive decline, people who experienced improvement in thinking tests and people in the middle.

Researchers said that 1,003 participants died. Researchers said that 34 percent of people with the fastest decline in thinking skills and 66 percent of people in the other two groups died at the end of the study.

After analyzing death certificates, researchers discovered that 21 percent of people in the group with the fastest decline died of cancer. However, 29 percent of people in the other two groups died of cancer.

Researchers said that findings suggest that people with the fastest cognitive decline were 30 percent less likely to die of cancer. The findings held true even after accounting for smoking, diabetes, heart disease, and other factors.

"We need to understand better the relationship between a disease that causes abnormal cell death and one that causes abnormal cell growth," Benito-León concluded. "With the increasing number of people with both dementia and cancer, understanding this association could help us better understand and treat both diseases."

The findings are published in the journal Neurology.