Lower risk of dementia for married or cohabiting people
People who live alone have twice the risk of developing dementia and Alzheimer's disease in later life compared with married or cohabiting people, according to a research study led by Dr Miia Kivipelto from Karolinska Institutet and published online in British Medical Journal.
According to Miia Kivipelto, being widowed or divorced in mid-life carries three times the risk of developing dementia. While there have been a number of studies linking being in a couple to good health and longevity this is the first study to focus on marital status and the risk of dementia.
The research group, from Finland and Sweden, interviewed a random sample of men and women derived from a group of 2000 adults. The participants came from two regions in Eastern Finland. They were initially surveyed at around 50 years of age and again around 21 years later. Participants were divided into the following groups: married/cohabitant, single, divorced or widowed. The team also investigated whether there was a link between living alone and being a carrier of the apolipoprotein E e4 gene variant (or allele), the known genetic risk factor for Alzheimer's disease.
The results reveal that people living without a partner during middle age had a higher risk of developing cognitive impairment in late life compared to those living with a partner. Individuals who become widowed at this age are three times more likely to develop dementia. The study also concludes that carriers of apolipoprotein E e4 gene variant who lose their partners and remain living alone have the highest risk of developing Alzheimer's disease.
These results are important for preventing dementia and cognitive impairment. As Dr Kivipelto explains: "We now know that it would be worth offering supportive intervention for individuals who have lost a partner."
As life expectancy increases in various regions of the world, dementia is becoming a growing health concern. In 2005 an estimated 25 million people had dementia, and the number is expected to reach 81.1 million by 2040.
Publication
Association between mid-life marital status and cognitive function in later life: population based cohort study.
BMJ 2009 Jul;339():b2462