Staying in a bad marriage could literally break your heart, the results of a new study suggest.

US researchers analysed data relating to around 1,200 married men and women and found that older people who were in bad marriages had a higher risk of developing heart disease compared to people in happy marriages.

"Marriage counseling is focused largely on younger couples. But these results show that marital quality is just as important at older ages, even when the couple has been married 40 or 50 years," they noted.

A bad marriage included cases where a spouse was particularly critical or demanding of their partner.

The study found that the effect of marital quality on heart health became significantly stronger as a person aged. The researchers from Michigan State University suggested that continuing stress associated with a bad marriage, a declining immune system and increasing frailty could all have a role to play.

The study also found that this negative effect appeared to be stronger in women. The researchers suggested this may be because women often internalise negative feelings, which can lead to depression and heart problems.

Meanwhile, the study also noted that heart disease can lead to ‘a decline in marital quality' for women, but not men. This, the researchers suggested, is in line with the theory that wives are more likely to care for their sick husbands than vice versa.

"In this way, a wife's poor health may affect how she assesses her marital quality, but a husband's poor health doesn't hurt his view of marriage," they commented.

Details of these findings are published in the Journal of Health and Social Behaviour.

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