Marriage: the midlife link to Alzheimer's

Being single around the age of 50 could be a significant risk factor for Alzheimer's.

A 21-year study of nearly 1,500 Finns suggests that people married in 'midlife' and others who live with partners, having regular close social interactions, have a 50% lower occurrence of dementia compared to those living alone. This was the case even after adjustments were made for education, obesity, cholestoral, blood pressure, occupation, physical activity, smoking habits, depression, genes, age and gender.

This is a significant difference and, with more and more people choosing to live alone, raises all sorts of interesting questions. For example, does it matter whether the relationship is happy or not?

The findings for particular sub-groups will raise concern among lone-wolf males. People who had been single all their life had a doubled risk of dementia, and divorcees who remained single had a tripled risk. Men take note: widowers before midlife who remained widowed had a six times higher risk of developing dementia compared with those who remain married throughout mid and late life.

'Marriage at an all-time low and ageing population'

Rebecca Wood, Chief Executive of the Alzheimer's Research Trust, said: 'These findings are particularly worrying for the UK: a society with a high divorce rate, marriage at an all-time low and ageing population. This is the first study of its kind to examine the link between midlife marital status and dementia, adding to previous research suggesting that social interaction reduces dementia risk.

'It is fascinating that cohabitation has such a beneficial effect. We urgently need more research into lifestyle factors and dementia risk if we are to halt the UK's dementia epidemic. 700,000 people in this country live with Alzheimer's and other dementias, a number expected to double within a generation.'

The study examined 1,449 individuals from the Finnish Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) study in midlife and then again in 1998, an average of 21 years later. At re-examination, 139 persons were diagnosed with some form of cognitive impairment: 82 with mild cognitive impairment (MCI) and 48 with Alzheimer's. The results are being presented by Krister HÃ¥kansson, above, of Sweden's Karolinska Institutet in Stockholm to the 2008 International Conference on Alzheimer's Disease (ICAD) in Chicago.

Research has previously shown that married men also tend to live longer.