Correlation or causation?

I’d like to think this is another data point for the validation of Dr. Joe’s Cure for Everything but I worry it is more about correlation than causation:

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.