Washington: Widowed people who never remarry are more likely to develop degenerative mental diseases like Alzheimer`s and dementia, a new study has claimed.
Researchers, who examined a detailed genealogical record of people born between 1895 and 1930, found that the risk of Alzheimer`s disease, the most common form of dementia, was 2.17 times higher in people who had been widowed and never remarried.
The results are preliminary and many questions remain about how other life stressors play a role in dementia, study researcher Maria Norton, a professor at Utah State University, told LiveScience.
But research on animals suggests that accumulated stress over the lifetime may speed cell death in the hippocampus, one of the brain`s memory centres. That might make the brain more vulnerable to the effects of Alzheimer`s disease, Norton said.
According to the US Alzheimer`s Association, about 5.4 million Americans currently have Alzheimer`s disease – the sixth-leading cause of death in the country.
The disease is marked by memory loss, disorientation and behaviour changes. No one knows why Alzheimer`s develops, but abnormal protein deposits called plaques and tangles seem to play a role in killing brain cells.
For their study, Norton and her colleagues wanted to know how life experiences might play a role in the development of Alzheimer`s and other dementias.
Using the Utah Population Database, the team collected biographical data from people born in the late 1800s and early 1900s and divided them into an array of categories reflecting complicated relationship histories: married and stayed married, married and divorced without remarrying, married and widowed without remarrying.
They also looked at people with multiple marriages, dividing them into categories based on whether any of those marriages had ended in widowhood or in divorce.
After controlling for age, gender, education and presence of the `APOE e4` gene variant, which is known to contribute to Alzheimer`s, the researchers found that multiple marital changes, especially widowhood, put people at elevated risk of developing dementia later.
The highest risk for dementia was among those who had married once, become widowed and never remarried. The least likely people to get dementia were those who stayed married and were not widowed, and those who got married, got divorced and stayed single.
A single divorce probably doesn`t increase dementia risk because the marriage itself was likely stressful and getting out was a relief, Norton said. On the other hand, widowhood can cause major life stress.
For the surviving spouse, Norton said, "this was something that wasn`t a conscious choice".
The researchers presented their findings at the annual meeting of the American Association for Geriatric Psychiatry.