Two new studies suggest that people who develop cancer may be less likely to come down with Alzheimer’s disease. Italian investigators collected data from more than 200,000 people over the age of 60 for six years. During that time roughly 10% were diagnosed with cancer. A bit more than 1% received a diagnosis of Alzheimer’s disease. There was less overlap between the two groups than statistics predicted. In other words, people with cancer were less likely to have dementia and people with Alzheimer’s were less likely to come down with cancer.
The results from Italy were similar to those found in a study of 3.5 million U.S. veterans conducted between 1996 and 2011. Depending upon the type of cancer, the risk of developing Alzheimer’s was lowered by anywhere from 9 to 50%. Chemotherapy, unlike radiation, was associated with an even greater reduction of Alzheimer’s disease risk. The drop was between 20% and 45%. The reasons for this inverse association remain unclear, but chemotherapy may have an anti-inflammatory impact on brain cells.
