Alcohol Harms the Brain More Than Marijuana
After the full legalization of marijuana in four U.S. states, scientists have begun actively studying its potential medical benefits and drawbacks. What exactly happens to brain cells when it is used? Researchers from the University of Colorado Boulder examined this question and suggested that cannabinoids may not damage the brain as much as alcohol does. More details about their work can be found in the journal Addiction.
The research team analyzed studies featuring brain scans that showed the effects of alcohol and marijuana on the brain. They concluded that long-term consumption of ethanol leads to changes in both the white and gray matter of the brain, while marijuana use does not significantly affect its integrity.
The authors note that, to date, attempts to study the effects of marijuana have produced mixed results. “One study reports that marijuana use is associated with a reduction in hippocampal volume. Then another study comes out saying its use is linked to changes in the cerebellum. The fact is, there is no consistency in all these studies regarding the actual brain structures,” they explain.
To try to fill this gap, the researchers conducted an analysis of existing neuroimaging data. Any reduction in the density of white or gray matter, or the destruction of their normal structure, could theoretically lead to impaired brain function.
During the study, MRI scans of 853 adults aged 18 to 55 and 439 adolescents aged 14 to 18 were analyzed. All participants varied in their use of alcohol and marijuana.
The researchers found that alcohol consumption, especially among adults who had been drinking for many years, correlated with a significant reduction in gray matter volume as well as decreased integrity of white matter. Marijuana, on the other hand, did not have such a strong effect on the structure of gray or white matter in either adolescents or adults.
Nevertheless, the team notes that it is still too early to judge the possible benefits and long-term consequences of marijuana use, and they plan to conduct further research.