The connection between marriage and health is a common area of study. New research suggests divorced or widowed people have 20 per cent more chronic health conditions than married people. (Daniel Roland/Associated Press)

Losing a spouse to divorce or death can have a lingering impact on health even after remarriage, a new study suggests.

Divorced or widowed people have 20 per cent more chronic health conditions such as heart disease, diabetes or cancer than married people, according to the study by U.S. researchers, reporting in the September issue of the Journal of Health and Social Behavior.

To come to that conclusion, the researchers studied 8,652 Americans aged 51 to 61, more than 95 per cent of whom were or had been married. Participants were interviewed in 1992.

The higher levels of chronic health problems among those who lost a spouse were found after taking factors such as race and gender into account.

The study could not prove a cause-and-effect relationship between an end of a marriage and poor health. Researchers could only confirm that idea by randomly assigning people to stay married or not, and observing what happens to the health of participants.

Previous studies have looked at the connection between health and marriage, with some finding better prospects for married men who survive surgery, compared to unmarried men.

Income, stress factors

But study author Prof. Linda Waite, a sociologist at the University of Chicago, set out to examine both marital transitions and marital status on a range of health conditions, including mobility problems and depressive symptoms.

Waite suggested divorce or widowhood may undermine health because incomes drop, and stress develops over issues such as shared child care.

The effects of marriage, divorce or remarriage on health are based on how the illnesses develop and heal, she said.

"Some health situations, like depression, seem to respond both quickly and strongly to changes in current conditions," Waite said in a release.

"In contrast, conditions such as diabetes and heart disease develop slowly over a substantial period and show the impact of past experiences, which is why health is undermined by divorce or widowhood, even when a person remarries."

The researchers also found divorced or widowed people had 23 per cent more mobility problems, such as trouble climbing stairs or walking a block, compared to married people.

Those who remarried had 12 per cent more chronic conditions, and 19 per cent more mobility limitations, with no more depressive symptoms than people who stayed married.

People who never married had 12 per cent more mobility problems and 13 per cent more depressive symptoms, but no other differences in chronic health conditions than married people, the researchers found.