Is there a protective link between cancer and Alzheimer’s?

An unexplained link between cancer and Alzheimer’s disease has been discovered by researchers in Italy. It is thought that those with Alzheimer’s are less likely to develop cancer and vice versa.

A study, looked at the health records of 204,468 people aged 60 and above for a 6 year period.  During this time there were 21,451 cases of cancer and 2,832 of Alzheimer’s disease.  The results showed that elderly people with Alzheimer’s are 50% less likely to develop cancer when compared to others of the same age, while those with cancer were 35% less likely to develop
Alzheimer’s.

Both conditions are linked to the aging process but cancer is caused by uncontrolled cell growth and Alzheimer’s is caused by the death of brain cells.  The link could be caused by genes which increase the risk of developing either of the conditions but mysteriously reduces the risk of developing the other.

Dr Catherine Roe of Washington University in St Louis, who first reported the link between the diseases in a 2005 paper, said, “There may be some genetic factor that, if it’s tipped one way, it may cause abnormal cell growth, and tipped another way, it may cause abnormal cell death.”

She added, “The ageing process could also provide an explanation, because as we grow older many cells stop dividing and release inflammatory proteins, which lowers the risk of cancer but may also trigger disorders of the brain.”