Research shows that patients with a history of cancer are less likely to develop dementia and those with Alzheimer’s are less likely to develop cancer. Understanding this relationship, say scientists, could lead to new treatments

With age comes disease. Cancer and Alzheimer’s dementia are among the commonest and most feared health conditions – particularly in countries with ageing populations such as the UK. Several decades ago, researchers at a psychiatric centre in New York observed a curious relationship between these two diseases. At autopsy, they found an inverse relation between cancer and Alzheimer’s disease.

In one of the first epidemiological studies on the topic Jane Driver of Brigham and Women’s Hospital in Boston, Massachusetts in the US followed 1,278 participants aged 65 and older for a mean of 10 years. Published in 2012, the results showed that cancer survivors had a 33% decreased risk of subsequently developing Alzheimer’s disease compared with people without a history of cancer.