The happier you are with your sex life, and the more you value it, the higher your intelligence may be into your 60s and 70s, a study of almost 2,000 people has found. The results support previous research suggesting sex slows the progress of dementia.

Without discouraging people from having more sex, the authors admit the direction of causation is uncertain. People with the sort of cognitive skills tested in this study may be better able to maintain good sexual relationships as they get older. On the other hand, why risk losing brain function just by not having enough sex?

As part of the Longitudinal Aging Study, Amsterdam, Dutch researchers tested a sample of men and women with an average age of 71 for memory, processing speed, fluid intelligence and general cognitive functioning. They then compared these with self-assessments of sexual satisfaction and ratings on the importance of sexuality. The work was consistent with several previous studies, but the authors hope the larger and more representative sample will see it taken more seriously by medical professionals.

Those who rated sexuality as important to them, as well as those who expressed satisfaction with their sex lives, scored higher on almost all measures than those who were less enthused about the whole thing. However, the difference was not always statistically significant after adjusting for confounding factors such as years of education and use of medication. The pattern was discernible for both men and women, although on some measures—such as fluid intelligence—it was restricted to women.

The paper has been published in the American Journal of Geriatric Psychiatry as part of a set on how sex relates to other aspects of elderly people's lives.

Another paper in the journal produced counterintuitive results regarding the relationship between sex and depression in octogenerian men. Depressed men in the group experienced more difficulties in daily living, but were not statistically different from their peers when it came to sexual practice. On the other hand, those with “subthreshold depression” were less interested in sex and had more anxiety about it than those with positive moods or those experiencing clinical depression.

A third study that was restricted to people living in a retirement home with a partner was more along the lines with what one would expect, with depressive symptoms more strongly associated with sexual dissatisfaction than with age, physical decline or anxiety. The good news was that more than 60% of those in the sample were somewhat or very satisfied with their sex lives and more than 70% were having sex at least once a week.

An editorial in the edition notes that sexuality is one of the “least understood and explored aspects of aging,” partially as a result of the myth that “older adults no longer value sexual activity...and [have] decreased desire for sexual intimacy.”