Researchers have discovered that older couples who have sex at least once weekly perform better on certain tests of cognitive ability.
The study - by researchers at Coventry University and the University of Oxford, both in the United Kingdom - is published in the Journals of Gerontology, Series B: Psychological and Social Sciences.
The research builds on earlier work, which found that sexually active older adults performed better on some tests of mental ability than those who were not sexually active.
However, it is not clear why such a link exists. The authors refer to other studies that have found that older adults who are physically active and also have busy social lives are likely to perform better on tests of mental function.
These might suggest that the link between sexual activity and cognitive function is just a reflection of the social and physical elements of sexual activity.
Lead author Dr. Hayley Wright, from the Centre for Research in Psychology, Behaviour and Achievement at Coventry University, and colleagues argue that sexual activity is a complex phenomenon with the potential to transcend not only its social and physical components, but also the emotional, psychological, and biological aspects.
They proposed that more frequent sexual activity may be linked with improved cognition, in the same way as such a link exists for other activities. Thus, they designed a study using a broader range of cognitive tests to investigate the link.
Study used range of cognitive tests
For their investigation, the team recruited 73 participants (28 men and 45 women) between 50 and 83 years of age, aged 62 on average.
The participants filled in a questionnaire that asked general questions about health and lifestyle, as well as how often they had engaged in sexual activity in the past 12 months. They were asked to respond with: once per week, once per month, or never.
Sexual activity was defined as "engagement in sexual intercourse, masturbation, or petting/fondling."
The participants also underwent tests of mental ability. One of these - the Addenbrookes Cognitive Examination III - includes assessment of memory, verbal fluency, language, attention, and visuospatial ability, which is the ability to visualize objects and the spaces between them.
The verbal fluency test involves naming as many animals as possible in 60 seconds, and then to say as many words starting with the letter "F" as possible. The visuospatial ability test includes drawing a clock face from memory and copying a complicated design.
In their analysis, the researchers adjusted the results to account for gender, age, number of years of formal education, and cardiovascular health. They took heart health into account as this might influence frequency of sex and brain function.
Frequency of sex linked to cognitive scores
The results showed that frequency of sexual activity did not change with age, education, cardiovascular health, marital status, quality of life, and other factors.
More participants reported having had sex once each week than once per month or never in the last 12 months.
Participants who reported never having sex scored lower on average for overall cognitive function and verbal fluency compared with participants who reported having sex every week.
Also, participants who reported having sex once every month scored lower on average for verbal fluency and marginally lower on visuospatial ability, compared with those who reported having sex at least once weekly.
The team found no link between frequency of sexual activity and attention, memory, or language ability.
Because of its design, the study cannot prove that more frequent sex increases brain function; it can only establish a link and its strength. However, the researchers claim that it does shed more light on the association.
As Dr. Wright argues, "Every time we do another piece of research we are getting a little bit closer to understanding why this association exists at all, what the underlying mechanisms are, and whether there is a 'cause and effect' relationship between sexual activity and cognitive function in older people."
She and her colleagues suggest that further studies should investigate the biological aspects of the link and examine, for instance, the roles of dopamine and oxytocin.
"People don't like to think that older people have sex - but we need to challenge this conception at a societal level and look at what impact sexual activity can have on those aged 50 and over, beyond the known effects on sexual health and general well-being."
Dr. Hayley Wright