Signs of an unhappy marriage shouldn't be ignored as older couples in bad marriages could be at a higher risk of heart disease, according to a new study.

Five years of data from 1,200 married men and women who participated in the National Social Life, Health and Aging project reportedly showed negative marriage qualities that can lead to signs of unhappy marriage has a bigger effect on heart health than positive marital qualities, according to MLive.

For the study, respondents reportedly completed surveys about the state of their marriages as well as lab tests and information concerning their heart health, including strokes, high blood pressure and heart attacks, according to CNN.

The effects of the unhappy marriage reportedly get stronger later on in life, according to Michigan State University sociologist Hui Liu's study of married couples in their 70s and 80s.

The recent study, which was published in the Journal of Health and Social Behavior, also reportedly showed that the hearts of older women are more affected by the quality of the marriage than their husbands. Liu reported that this is "possibly because women tend to internalize negative feelings and thus are more likely to feel depressed and develop cardiovascular problems."

The results of the study show that the need for a happy, healthy marriage is crucial for couples of all ages.

"Marriage counseling is focused largely on younger couples," stated Liu on her university's website.

She added, "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."