We already know that a bad sex life can lead to relationship problems and may raise the risk of heart disease.
But now scientists at Penn State University say that it could also leave men at higher risk of suffering from dementia.
In a study involving 818 men in their 50s who were tracked for more than a decade, scientists found those who had poor sex lives showed a faster decline on memory tests than those who did not.
Scientists suggested this may be because individuals with poor sex were more likely to face chronic stress, which could cause atrophy of the areas of the brain linked to memory. But they also suggested it could be a sign of poor heart health, which is also known to raise the risk of memory problems.
In the study, published today in the journal of the Gerontological Society of Ameria, the scientists recruited people who served in the US military between 1965 and 1975.
Participants were about 56 years old on average at the start of the study but had turned 68 by the end.
None had erectile dysfunction or cognitive impairment at the start of the study.
Each was questioned at the start of the study and twice more at six-year intervals for the next 12 years.
They were asked about their sexual satisfaction, with participants filling in self-reported assessments on their relationship, or relationships, and intercourse.