(Newser) – Past or present drug use doesn't seem to damage middle-aged brains, a new study finds. British researchers studied the mental sharpness of thousands of 50-year-old subjects, and found that those who had used illicit drugs—mainly marijuana—actually performed better than others on tests of memory and other brain functions, Reuters reports. Around a quarter of test subjects said they had taken drugs at some point in their lives; 6% were still using drugs in their 40s.

The middle-aged tokers may have scored higher than others because the drug users tended to have a higher education level than non-users, the researchers say. "The results seem to suggest that past or even current illicit drug use is not necessarily associated with impaired cognitive functioning in early middle age," the lead researcher says. "However, our results do not exclude possible harmful effects in some individuals who may be heavily exposed to drugs over longer periods of time." (Read more drug use stories.)

