Many people know that smoking can harm the lungs, but fewer people think about what it does to the brain. A new large study now shows that both cannabis and tobacco may change the structure of the brain in ways that could affect thinking, emotions, and memory.
The research was published in the journal Addiction and reviewed over 100 studies from around the world. In total, it included information from more than 72,000 people. By combining so many studies, scientists were able to see clear patterns that smaller studies could not show on their own.
Cannabis and tobacco are both common substances. Cannabis is used by millions of people, often for relaxation or recreation. Tobacco, mainly in the form of cigarettes, is even more widely used and remains a leading cause of preventable death worldwide.
Both substances act on the brain. Cannabis contains THC, which changes how the brain processes feelings and sensations. Tobacco contains nicotine, which affects communication between brain cells and can lead to addiction.
The researchers wanted to understand how these substances affect the physical structure of the brain. They focused on brain volume, which is a measure of the size of different brain regions. Changes in brain volume can be linked to changes in function.
The findings showed that cannabis users often have a smaller amygdala. This area of the brain helps control emotions and reactions to stress. A smaller amygdala may change how people experience fear or emotional events.
Tobacco use was linked to changes in several areas of the brain. These included the insula, which helps people understand their own feelings, and the pallidum, which is involved in movement and motivation. Smokers also showed changes in overall gray matter, which is important for thinking and memory.
One of the most concerning findings was that smokers tend to lose gray matter faster over time than non-smokers. This may increase the risk of problems with thinking and mental health as they age.
The study also used genetic data to better understand the link between smoking and brain changes. It found that heavier smoking was connected to a smaller hippocampus, the part of the brain responsible for learning and memory.
By combining different types of studies, including long-term studies and genetic analysis, the researchers were able to strengthen their conclusions. This approach helps reduce the chance that the results are due to other factors.
These findings give a clearer picture of how cannabis and tobacco affect the brain. Instead of general warnings, doctors can now point to specific brain regions that may be affected.
If you care about cannabis, please read studies that what you need to know about cannabis and heart attack, and CBD from cannabis may help inhibit COVID-19 infection.
For more information about cannabis, please see recent studies that medical cannabis could help reduce depression, and results showing this stuff in cannabis may protect aging brain, treat Alzheimer’s.
Source: University of Bath.
