Teen marijuana use doesn’t result in reduced brain tissue health, according to a study that compared marijuana and alcohol use with brain tissue health.
Researchers scanned the brains of 92 teens between the ages of 16 and 20 before and after an 18-month period. During that time, half of the teens who already used marijuana and/or drank alcohol continued to do so. The other half refrained from partaking, or partook in small amounts.
The Huffington Post reports that the before and after brain scans of teens who used alcohol frequently (five or more drinks at least twice per week) showed a reduced amount of white brain tissue. The study showed, however, that teens who used marijuana heavily had no reduced white matter tissue.
The researchers noted that they did not test the teens’ performance before and after, but just looked at brain scans. The researchers who conducted the study work at US San Diego and the study will be published in the April issue of the journal Alcoholism: Clinical & Experimental Research.
The San Francisco Chronicle notes that researchers believe that the reaction of lessened white brain tissue is caused by ethanol, a known neurotoxin, while ingredients in cannabis, like cannabidiol, are proven to protect the brain. It is already known that alcohol causes damage to the nerves in the brain, as well as cancer, strokes, and an increased risk of suicide.
In comparison, ingredients in cannabis have not. Joanna Jacobus, a postdoctoral fellow at the University of California in San Diego, stated:
“One reason is that marijuana can really vary. Different strains contain different levels of THC and other marijuana components. For example, some studies have suggested one component, cannabidiol, may actually have neuroprotective effects.”
The study’s authors stated that more research will be needed to determine what the exact difference is between use of the two substances, as well as if the reduced brain tissue health is permanent.