Commonly we are told that marriage is good for our health, and naturally this leads many people to assume that “any marriage is better than no marriage.” However, this blind trust in the positive effects of marriage may be far from the truth for women who are unhappily wed. Compared to good marriages, a new study finds, unhappy unions raise the risks of heart disease, especially among older women.

“Our results suggest that the stress process operating within marriage may be more important than the supportive aspect of marriage in shaping individuals’ cardiovascular health,” wrote Dr. Hui Lui, lead author of the study and an associate professor of sociology at Michigan State University.

Cardiovascular disease (CVD) is the leading cause of death and disability in the United States, with nearly 600,000 Americans dying of it each year — that’s a quarter of all deaths! As we age, our risk of developing some form of heart disease increases. While 40 percent of men and one third of all women suffer from CVD between the ages of 40 and 59, these numbers spike to nearly 70 percent and 71 percent during the next two decades.

Identifying A Good Marriage

Since many personal, social, and behavioral factors influence cardiovascular health, many researchers are trying to identify precise ways to prevent this disease. Such is the case with the current study. Liu and her colleague began by analyzing five years of data from participants in the National Social Life, Health and Aging Project. Respondents, including 459 married women and 739 married men, began the study when they were between the ages of 57 and 85. The researchers performed lab tests to measure hypertension, heart rate, and levels of C-reactive protein in the blood, while also recording past medical history, including strokes and heart attacks.

The project quizzed participants on their marital quality with these and other questions: Do you and spouse spend free time together or apart? How often can you rely on spouse? How often does spouse make too many demands on you? How close do you feel is your relationship with spouse? How often does spouse criticize you? How often does spouse get on your nerves?

After analyzing all the data, Liu drew two important conclusions. First, the results suggest that changes in marital quality and cardiovascular risk are more closely related for older married people than for younger. Second, the link between marital quality and cardiovascular risk appeared to be more pronounced among women than among men at older ages.

Notably, Liu and her co-researcher found heart health and marriage health to be a two-way street — at least for women. Heart disease led to a decline in marital quality for women, though not for men; the researchers suggest this may be due to the fact that wives are more likely to provide care and support to sick husbands, while husbands are less likely to do the same for their sick wives.

On a positive note, the researchers discovered a good marriage can lower the risk of cardiovascular disease. Final take-away message? Look before you leap.

Source Lui H, Waite L. Bad marriage, broken heart? Age and gender differences in the link between marital quality and cardiovascular risks among older adults. Journal of Health and Social Behavior. 2014.