People with HIV who smoke pot may have less cognitive decline related to the virus compared with those who abstain. This theory derives from a small study investigating the relationship between THC, a key chemical in marijuana, and markers of the sort of inflammation associated with HIV-related cognitive decline.

Publishing their findings in the journal AIDS, researchers studied blood samples from 40 people with HIV who reported whether they smoked pot. Isolating the white blood cells from the samples and studying THC’s effect on them in laboratory experiments, the study authors found that the non–pot users had very high levels of key inflammatory cells compared with the pot smokers. Those who smoked marijuana had levels of these inflammatory cells similar to those seen in HIV-negative individuals.

This paper suggests that THC acts as an anti-inflammatory agent. Much more extensive research is needed to further investigate THC’s role in inflammation among HIV-positive individuals and how this component of marijuana may thus affect the trajectory of cognitive function over time.

To read a press release about the study, click here.

To read the study abstract, click here.