By Fiona Macrae
5th May 2010
Those who nurse a spouse with dementia are six times more likely to develop the devastating condition themselves, research shows.
It is thought the physical and mental stress of caring for a loved one with Alzheimer's and other forms of the condition can do lasting damage to the brain's memory centre.
Although all forms of caring are hard, watching the mental decline of dementia is particularly tough, say the researchers, with men feeling the effects particularly keenly.
With the number of people with dementia expected to explode as the population ages, they say a better understanding of the phenomenon is vital and call for more
research. The study team from Utah State University in the U.S. spent 12 years tracking the health of more than 1,200 couples who had been married for an average of 49 years.
None had dementia at the start of the study, but by the end 225 coueaseples were affected. In 125 of these, the husband was diagnosed and in 70 it was the wife. But in 30 couples, both spouses were affected .
When factors such as genetics and social class were taken into account, it became clear that having a husband or wife with the disease raised a person's risk of developing it themselves six-fold.
The study, reported in the Journal of the American Geriatrics Society, found husbands to be three times were vulnerable than wives, although the small numbers involved mean this might just be down to chance.
The researchers believe the emotional stress of watching the mental decline of a loved one could be at least partly to blame. In addition, dementia usually strikes later in life, making the psychological burden heavier for ageing spouses.
But the team called for more research on shared lifestyle and environmental factors.
At least 600,000 people in England have some form of dementia while an estimated 1.4million Britons will be sufferers within 20 years.
Rebecca Wood, of the Alzheimer's Research Trust, said last night: 'It should be made clear that the majority of participants whose spouse had dementia did not develop the condition.
'Scandinavian researchers have found that being married in old age generally reduces risk, maybe because of the greater social interaction couples experience'.