A few days ago I published a brief article, Chocolate Brain, which discussed the cognitive benefits of eating chocolate. Bottom line: people who eat chocolate (like my sister) have better cognition than people who don’t. As always, there are some caveats, but it seems that good cognition and chocolate go hand in hand.
I was headed to the chocolate store when I was stopped in my tracks by a newly published article in the journal, Age and Ageing. The title, “Sex on the brain! Associations between sexual activity and cognitive function in older age” pretty much explains it all. (Click here for the full text).
The two studies – chocolate versus sex – are remarkably parallel. Both use data collected over the years through longitudinal studies. The chocolate study looked at almost 1,000 Americans who have been studied since 1975 in the Maine-Syracuse Longitudinal Study. The sex study looked at data from almost 7,000 people who have participated in the English Longitudinal Study of Aging (ELSA).
Both longitudinal studies gather data at periodic intervals; both studies are now on wave 6. The chocolate study included people aged 23 to 98. The sex study looked only at older people, aged 50 to 89.
Both studies also used standard measures of cognition. The chocolate study used six standard measures of cognition. The sex study used two: “…number sequencing, which broadly relates to executive function, and word recall, which broadly relates to memory.”
Both studies looked at the target variable – chocolate or sex – in binary fashion. Either you ate chocolate or you didn’t; either you had sex – in the last 12 months – or you didn’t.
The results of the sex test differed by gender. Men who were sexually active had higher scores on both number sequencing and word recall tests. Sexually active women had higher scores on word recall but not number sequencing. Though the differences were statistically significant, the “…magnitude of the differences in scores was small, although this is in line with general findings in the literature.”
As with the chocolate study, the sex study establishes an association but not a cause-and-effect relationship. The researchers, led by Hayley Wright, note that the association between sex and improved cognition holds, even “… after adjusting for confounding variables such as quality of life, loneliness, depression, and physical activity.”
So the association is real but we haven’t established what causes what. Perhaps sexual activity in older people improves cognition. Or maybe older people with good cognition are more inclined to have sex. Indeed, two other research papers cited by Wright et. al, studied attitudes toward sex among older people in Padua, Italy and seemed to suggest that good cognition increased sexual interest rather than vice versa. (Click here and here). Still, Wright and her colleagues might use a statistical tool from the chocolate study. If cognition leads to sex (as opposed to the other way round), people having more sex today should have had higher cognition scores in earlier waves of the longitudinal study than did people who aren’t having as much sex today.
So, we need more research. I’m especially interested in establishing whether there are any interactive effects. Let’s assume for a moment that sexual activity improves cognition. Let’s assume the same for chocolate consumption. Does that imply that combining sex and chocolate leads to even better cognition? Could this be a situation in which 1 + 1 = 3? Raise your hand if you’d like to volunteer for the study.