Long-term cannabis smoking can lead to structural damage in parts of the brain, according to a recent study. Cannabis, or marijuana, is often believed to be generally harmless by smokers and some non-smokers, but the results of this study suggest otherwise.
It’s estimated that upwards of 15 million Americans use marijuana recreationally in a given month. Many of these individuals are, or become, chronic smokers, which past studies have shown could greatly increase risk of lung cancer and gum disease. Moderate marijuana use was not addressed in this study.
Researchers took detailed magnetic resonance images (MRI’s) of 15 men who had smoked an average of five or more joints daily for the past ten years. The average age of the participants was 39.8 years. These images were compared with images of 16 non-cannabis smokers who averaged 36.4 years of age.
It was seen from the images that in chronic cannabis smokers, “the hippocampus, thought to regulate emotion and memory, and the amygdala, involved with fear and aggression, tended to be smaller in cannabis users than in controls.” Chronic smokers also performed significantly worse than controls in verbal learning.
While medicinal cannabis smoking, such as to relieve chronic pain or decreased appetite in patients suffering from AIDS or chemotherapy cancer treatment, has been supported by many in the medical field, recreational use is still controversial and thought to provide little benefit. For chronic smokers, increased risk of lung cancer, gum disease, and now brain damage, are becoming evident.
Source: Defeat Diabetes Foundation: Yocel, Murat. JAMA news release. June 2008.