With the legalization of marijuana on the rise, an increasing number of studies are exploring the potential harms and benefits of the drug.
Scientists from the University of Colorado Boulder conducted a review of existing imaging data that examined the effects of alcohol and marijuana, or cannabis, on the brain.
Study leader Rachel Thayer, from the Department of Psychology and Neuroscience and colleagues, recently reported their findings 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 becoming increasingly legalized for medicinal and recreational purposes. As a result of this changing legislation, researchers have been trying to uncover more about how marijuana may benefit health, as well as the harms it could cause.
For example, last year, Medical News Today reported on a study linking marijuana use to an increased risk of psychosis in teenagers, while another study claimed that the drug is “worse than cigarettes” for cardiovascular health.
On the flip side, researchers found that cannabinoids could help prevent migraines and increase libido.
“When you look at these studies that go back years,” he explains, “you see that one study will report that marijuana use is related to a reduction in hippocampal volume. The next study says that marijuana use is related to changes in the cerebellum […].”
“The point is that there is no consistency across all these studies in terms of the actual brain structures.”
The researchers conducted a new analysis of existing brain imaging data. They examined how marijuana use affects white matter and gray matter in the brain, and how its effects compare to another “drug” we have become so accustomed to: alcohol.
Gray matter is the tissue on the surface of the brain that consists mainly of nerve cell bodies. White matter is the deeper brain tissue that contains myelinated nerve fibers, which are protruding branches of 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 loss of its integrity can lead to impairments in brain functioning.
The study included brain images from 853 adults aged 18 to 55 years and 439 teenagers aged 14 to 18 years. 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 white matter integrity.
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 much more harmful to brain health than using marijuana.
“[…] while marijuana may also have some negative consequences, it definitely does not come close to the negative consequences of alcohol.” – Kent Hutchison
Source: www.medicalnewstoday.com, by Honor Whiteman