The investigators also found that more negative interactions between partners were linked to having thicker carotid arteries, which are the blood vessels that carry blood through the neck to the brain. Thicker carotids are linked with increased risk of cardiovascular disease.
The study "contributes to that body of evidence that shows that there is something about marital interactions that affects [people's] health," study author Nataria Joseph, now at the VA Greater Los Angeles Healthcare System, told Live Science. [6 Scientific Tips for a Successful Marriage]
In the study, the researchers examined 281 healthy, employed, middle-age adults who were married or living with partners in marriagelike relationships. The participants answered questions about their relationship satisfaction. The researchers also used a "real-time" relationship quality assessment method, in which people reported how they felt about very recent interactions that happened about an hour before they reported them to the researchers, rating the interactions as negative or positive.
The interactions that the researchers looked at "may be closely tied to emotions, health behaviors and physiology, all of which have effects on health," Joseph said.
The researchers also measured the thickness of the participants' carotid arteries using ultrasound imaging. The difference in artery thickness between the groups meant that those with the fewest positive interactions had an 8.5-percent increased risk of heart disease compared with those with the most positive interactions, the researchers said.
Exactly how your interactions with your spouse may affect the thickness of your arteries remains unclear, the researchers said. In the study, the researchers looked at whether changes in blood pressure had anything to do with the link, but they did not find this was the case, Joseph said.
The association between marital interactions and carotid artery thickness was also independent of how often partners interacted, as well as their personality traits, the researchers said.
The study is limited in that all the data was collected at the one point in time, and therefore it shows a correlation, but not a cause-and-effect relationship between interactions and thicker carotid arteries, Joseph said.
However, "health care providers should look at relationships" in their patients' lives, she said. "They are likely to promote health, or place health at risk."
source: livescience.com By Agata Blaszczak-Boxe