More Research Needed on How Cannabis Affects the Brain, Says American Heart Association
There’s still much researchers don’t know about how cannabis affects the brain, according to the American Heart Association (AHA).
For instance, there is limited information comparing the different effects of recreational, illicit, and medicinal uses of cannabis, as well as the type of product consumed.
In a scientific statement published in the journal Stroke, AHA researchers detailed the known effects of cannabis on the brain – including the detrimental ones – while highlighting the weaker areas of research.
The heart of the matter
The statement is the AHA’s first on cannabis and brain health, following a statement on marijuana and cardiovascular health published in 2020, which noted the link between regular cannabis use and cardiovascular disease.
The new statement primarily summarizes the known effects of cannabis chemicals on brain activity – for instance, that THC interacts with endocannabinoid CB1 receptors, which are found throughout the brain.
In particular, the statement highlights several animal studies that documented the negative effects of cannabis on the brain, such as cognitive deficits.
“Data obtained in these animal studies demonstrate that disruption of endocannabinoid pathways leads to behavioral and cognitive abnormalities, such as poorer memory and learning ability and a heightened sensitivity to stress,” Fernando D. Testai, a professor of neurology and rehabilitation at the University of Illinois at Chicago and lead author of the scientific statement, said in a statement.
“Also, there may be vital life periods – gestation and adolescence – when the brain may be particularly vulnerable to the impact of THC.”
Considering these known cognitive defects of cannabis, Fernando and his colleagues have called for more surveillance programs to assess the risks of cannabis in populations.
“Social media may emphasize a beneficial role for marijuana, and the general population may perceive it as a harmless drug,” they write in their closing remarks.
“However, the emerging evidence linking marijuana use to cardiovascular events and stroke, as well as the potential and demonstrated drug-to-drug interactions between marijuana and medications commonly used in the general population, calls for caution and highlights the potential importance of active surveillance programs.”
Further to these surveillance projects, the AHA researchers also call for more thorough studies into cannabis’ effects on the brain, to help elucidate some of the conflicting results of existing studies.
“Observational studies have produced conflicting results in relation to the effect of marijuana on different outcomes of interest, including hypertension, AF [atrial fibrillation], MI [myocardial infarction], and cognition,” they write.
“It should be noted that the overarching goal of this scientific statement was to discuss mechanisms by which marijuana use could influence brain health. However, as the field is developing, several important aspects require additional research,” they continue.
