A healthy sex life in old age may help keep the brain healthy as well, though this connection may not work the same way for both sexes, a U.K. study suggests.
After adjusting for other factors that might explain the link between brain function and sexual habits - age, relationship status, living arrangements, education, wealth, exercise routines, depression, loneliness and quality of life - older men's sexual activity levels were still tied to how well they did on both word-recall and number sequencing tests, the study found.
But in women, only word recall was associated with sex.
Number sequencing broadly relates to thinking skills known as executive function, while word recall is tied specifically to memory, the study authors note in Age and Ageing.
"Whilst our research is not concerned with how men and women `think' about sex in a conscious sense, it is possible that our results may be related to hormones which affect the brain - and hence cognitive functions - in men and women differently, at a subconscious level," co-author Hayley Wright of Coventry University told Reuters Health by email.
To explore the connection between an active sex life and a healthy brain, Wright and co-author Rebecca Jenks, also of Coventry University, reviewed survey data and cognitive tests results for about 6,800 adults aged 50 to 89 years.
Among other things, the survey asked if respondents had any sexual activity during the previous year.
Men and women who answered in the affirmative were likely to be more educated, wealthier, younger, more physically active, not depressed and less lonely.
Even after factoring in these aspects of the men's lives, sexual activity was associated with higher scores on the cognitive tests, although the magnitude of difference in test results was small.
This type of study based on conditions at a single point in time when the participants took the survey cannot prove cause and effect, the authors acknowledge. Future studies that follow people over time will have to explore whether sex improves brain function, or, for that matter, whether the opposite is true and a sharper mind contributes to a better sex life, they note.
The researchers also arrived at the study population after excluding more than 3,000 people who didn't answer the survey question about sex from an original sample of 10,000, which means the results could be biased.
"Bias related to differential participation in the sexuality questionnaire - either by gender or by cognitive function - could explain the gender differences reported here," noted Dr. Stacy Tessler Lindau, director of the Program in Integrative Sexual Medicine at the University of Chicago.
More research is needed to understand how executive functions in the brain govern human sexuality and whether an active sex life might help ward off age-related mental decline, Lindau, who wasn't involved in the study, added by email.
"However, there is ample evidence to suggest that loving, kind and supportive relationships are very important for both a satisfying sex life and for mental well-being throughout the life course," Lindau said. "Whatever patients and societies can do to promote kindness and love is likely to benefit mental wellness as we age."