Older adults who are starting to suffer from memory problems but have not yet developed dementia could have a lower risk of dying from cancer than those who are mentally sharp.
"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 an American Academy of Neurology news release. "One possibility is that cancer is underdiagnosed 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 research team looked at 2,627 adults over the age of 65 in Spain who did not suffer from dementia at the beginning of the study. The participants were tested on their memory and thinking skills at both the beginning and end of the three-year period; they were followed for an average of 13 years.
The study subjects were divided into three groups: "those whose scores on the thinking tests were declining the fastest, those whose scores improved on the tests, and those in the middle," the news release reported.
During the study period 1,003 participants passed away; 339 (34 percent) of the deaths were in the group with the highest rate of mental decline. There were 664 deaths (64 percent) in the other two groups. Twenty-one percent of the deaths in the group with the highest mental decline were from cancer, compared to 29 in the other two groups.
This statistic remained true even when the researchers adjusted for other risk factors such as "smoking, diabetes and heart disease," the news release reported.
"We need to understand better the relationship between a disease that causes abnormal cell death and one that causes abnormal cell growth," Benito-León said. "With the increasing number of people with both dementia and cancer, understanding this association could help us better understand and treat both diseases."
