Having sex frequently – and enjoying it – puts older men at higher risk for heart attacks and other cardiovascular problems. For older women, however, good sex may actually lower the risk of hypertension.

That’s according to the first large-scale study of how sex affects heart health in later life. The federally funded research, led by a Michigan State University scholar, is published online in the Journal of Health and Social Behavior.

“These findings challenge the widely held assumption that sex brings uniform health benefits to everyone,” said Hui Liu, an MSU associate professor of sociology whose vast research on the link between health and relationships has been featured in the New York Times, USA Today, NPR, Time and many other national and international news outlets.

For the current study, Liu and colleagues analyzed survey data from 2,204 people in the National Social Life, Health and Aging Project. Participants were aged 57-85 when the first wave of data was collected in 2005-06; another round of data was collected five years later. Cardiovascular risk was measured as hypertension, rapid heart rate, elevated C-reactive protein and general cardiovascular events：heart attack, heart failure and stroke.

Older men who had sex once a week or more were much more likely to experience cardiovascular events five years later than men who were sexually inactive, the study found. This risk was not found among older women.

“Strikingly, we find that having sex once a week or more puts older men at a risk for experiencing cardiovascular events that is almost two times greater than older men who are sexually inactive,” said Liu. “Moreover, older men who found sex with their partner extremely pleasurable or satisfying had higher risk of cardiovascular events than men who did not feel so.”

She said the findings suggest the strain and demands from a sexual relationship may be more relevant for men as they get older, become increasingly frail and suffer more sexual problems.

“Because older men have more difficulties reaching orgasm for medical or emotional reasons than do their younger counterparts, they may exert themselves to a greater degree of exhaustion and create more stress on their cardiovascular system in order to achieve climax.”

Testosterone levels and the use of medication to improve sexual function may also play a role. “Although scientific evidence is still rare,” Liu said, “it is likely that such sexual medication or supplements have negative effects on older men’s cardiovascular health.”

Ultimately, while moderate amounts of sex may promote health among older men, having sex too frequently or too enjoyably may be a risk factor for cardiovascular problems, Liu said. “Physicians should talk to older male patients about potential risks of high levels of sexual activity and perhaps screen those who frequently have sex for cardiovascular issues.”

For women, it was a different story. Female participants who found sex to be extremely pleasurable or satisfying had lower risk of hypertension five years later than female participants who did not feel so.

“For women, we have good news：Good sexual quality may protect older women from cardiovascular risk in later life,” Liu said.

Previous studies suggest that strong, deep and close relationship is an important source of social and emotional support, which may reduce stress and promote psychological well-being and, in turn, cardiovascular health.

“This may be more relevant to women than to men,” Liu said, “because men in all relationships, regardless of quality, are more likely to receive support from their partner than are women. However, only women in good quality relationships may acquire such benefits from their partner.”

Moreover, the female sexual hormone released during orgasm may also promote women’s health, she said.

Liu’s co-authors are Linda Waite, professor at the University of Chicago, Shannon Shen, an MSU graduate student, and Donna Wang, professor of medicine at MSU.

The research was partially funded by the National Institute on Aging, the National Institute of Child Health and Human Development, the Office of Behavioral and Social Sciences Research, and the National Heart, Lung and Blood Institute, which are all part of the National Institutes of Health.