Study: Marijuana May Protect Against Alcohol Brain Damage
WASHINGTON, D.C. -- A study just published online by the journal Neurotoxicology and Teratology suggests that marijuana may protect the brain from some of the damage caused by binge drinking.
The study, by researchers at the University of California San Diego, used a type of high-tech scan called diffusion tensor imaging to compare microscopic changes in brain white matter. The subjects were students aged 16-to-19, divided into three groups: binge drinkers (defined as having five or more drinks at one sitting for boys or four or more for girls), binge drinkers who also smoked marijuana, and a control group who had very little or no experience with either alcohol or drugs.
As expected, the binge-drinking-only group showed evidence of white matter damage in eight regions examined, as demonstrated by lower fractional anisotropy (FA) scores. But in a finding the researchers describe as "unexpected," the binge-drinking/marijuana group had lower FA scores than the controls in only three of eight regions, and in seven regions the binge-drinking/marijuana group had higher scores -- indicating less damage -- than the binge drinkers who did not use marijuana.
Brain white matter tracts were "more coherent in adolescents who binge drink and use marijuana than in adolescents who report only binge drinking," the researchers wrote. "It is possible that marijuana may have some neuroprotective properties in mitigating alcohol-related oxidative stress or excitotoxic cell death," as has already been shown in lab and animal studies.
"This study suggests that not only is marijuana safer than alcohol, it may actually protect against some of the damage that booze causes," said Steve Fox, Marijuana Policy Project director of state campaigns and co-author of the new book, "Marijuana Is Safer: So Why Are We Driving People to Drink?" (which hit number 17 on the Amazon.com bestseller list). "It's far better for teens not to drink or smoke marijuana, but our nation's leaders send a dangerous message by defending laws that encourage the use of alcohol over marijuana."
REFERENCE: Jacobus, J. et al. "White matter integrity in adolescents with histories of marijuana use and binge drinking." Neurotoxicology and Teratology. http://dx.doi.org/10.1016/j.ntt.2009.07.006
