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| EFFECT OF ALCOHOL TO THE BRAIN |
With marijuana legalization in USA, an increasing number of studies are exploring the drug's potential harms
and benefits. However, a new study suggests that when it comes to brain health,
alcohol is more damaging.
Scientists at the University of
Colorado Boulder conducted a review of existing imaging data that looked at the
effects of alcohol and marijuana, or cannabis, on the brain.
Their findings linked alcohol
consumption with long-term changes to the structure of white matter and gray
matter in the brain.
The use of marijuana, however,
seemed to have no significant long-term effects on brain structure.
Study leader Rachel Thayer, of the
Department of Psychology and Neuroscience at the University of Colorado
Boulder, and colleagues recently reported their results in the journal Addiction.
It is estimated that around 22.2
million people in the United States have used marijuana in the past month,
making it "the most commonly used illicit drug" in the country.
Across the U.S., however, it is
increasingly becoming legalized for both medicinal and recreational purposes.
As a result of this changing legislation, researchers have been trying to find
out more about how marijuana may benefit health, as well as the damage that it
could cause.
On the other side of the coin,
researchers have found that cannabinoids — which are the active compounds in
marijuana — could help to prevent migraine, and a more recent study linked
marijuana use to an increased sex drive.
Marijuana
vs. Alcohol: Which is worse?
For this latest study, Thayer and
colleagues sought to learn more about how marijuana use affects the brain.
Study co-author Kent Hutchison, also
of the Department of Psychology and Neuroscience, notes that to date, studies
that have investigated this association have produced mixed results.
"When you look at these studies going back
years," he explains, "you see that one study will report that
marijuana use is related to a reduction in the volume of the hippocampus.
The
next study then comes around, and they say that marijuana use is related to
changes in the cerebellum
"The point is that there's no
consistency across all of these studies in terms of the actual brain
structures."
With the aim of closing the gap on
this inconsistency, the researchers conducted a new analysis on existing brain
imaging data. They looked at how marijuana use affects white matter and gray
matter in the brain, and how its effects compare with another "drug"
that we have become so accustomed to: alcohol.
Gray matter is the tissue on the
brain's surface that primarily consists of nerve cell bodies. White matter is
the deeper brain tissue that contains myelinated nerve fibers, which are
branches protruding from nerve cells that transmit electrical impulses to other
cells and tissues.
The team notes that any reduction in
the size of white or gray matter or a loss in their integrity can lead to
impairments in brain functioning.
"With alcohol, we've known it's
bad for the brain for decades," notes Hutchison. "But for cannabis,
we know so little."
Marijuana
use had no impact
The study included the brain images
of 853 adults who were aged between 18 and 55 years and 439 teenagers between
the ages of 14 and 18. All participants varied in their use of alcohol and
marijuana.
The researchers found that alcohol
use — particularly in adults who had been drinking for many years — was
associated with a reduction in gray matter volume, as well as a reduction in
the integrity of white matter.
Marijuana use, however, appeared to
have no impact on the structure of gray or white matter in either teenagers or
adults.
Based on these findings, the
researchers believe that drinking alcohol is likely to be much more harmful to
brain health than using marijuana.
while marijuana may also have some
negative consequences, it definitely is nowhere near the negative consequences
of alcohol."
Kent Hutchison
When it comes to the possible
benefits of marijuana use, however, Thayer and her team note that the jury is
still out, and further research is needed to reach some conclusions.
