Regular Intercourse Protects Against Erectile Dysfunction: Tampere Aging Male Urologic StudyYou can also find the abstract here, and the full article here. It is not a joke.
Erectile dysfunction is common among men aged more than 60 years. Its cause involves both physiologic and psychosocial factors.
To evaluate the effects of coital frequency on subsequent risk of erectile dysfunction, data were analyzed from a population-based 5-year follow-up study that was conducted in Pirkanmaa, Finland, using postal questionnaires. ...
The overall incidence of moderate or complete erectile dysfunction was 32 cases per 1000 person-years ... The risk of erectile dysfunction was inversely related to the frequency of intercourse. ...
Regular intercourse protects against the development of erectile dysfunction among men aged 55 to 75 years. This may have an impact on general health and quality of life; therefore, doctors should support patients' sexual activity.
The authors claim to have found a cause-and-effect relationship, and not just a correlation. That is, lack of intercourse causes ED, and not the other way around.
Maybe next someone will do research to show that people who do regular push-ups are less likely to lose the ability to do push-ups.