Alcohol abuse can cause numerous health problems, and recently, scientists have found it also rewires your brain.
A study published in Progress in Neurobiology on Novermber 13, 2020, found that changes in the amygdala’s cellular activity may result in alcohol addiction. The amygdala, a small almond-shaped region located deep within the brain, regulates emotions, behavior, and motivation. When the anti-inflammatory mechanisms and cellular activity become disrupted, it can result in addictions to various substances.
Marisa Roberto, Ph.D., a professor in Scripps Research’s Department of Molecular Medicine, and her team studied these changes within the amygdala.
For the first time, they found how alcohol abuse rewires the brain, specifically the amygdala. When they experimented with mice, they found a way to counter this process and stop excessive alcohol consumption. This shows promise for future treatment plans for alcohol abuse.
How alcohol changes the brain
“We found that chronic alcohol exposure compromises brain immune cells, which are important for maintaining healthy neurons,” says Reesha Patel, Ph.D., a postdoctoral fellow in Roberto’s lab and first author of the study. “The resulting damage fuels anxiety and alcohol drinking that may lead to an alcohol use disorder.”
The study focused on a ubiquitous immune protein in the brain called Interleukin 10, or IL-10. Known for its powerful anti-inflammatory effect, this protein tells the immune system not to overreact to threats.
In the brain, IL-10 helps keep inflammation down from injuries or diseases, such as a stroke or concussion. Low levels of this protein in the brain have been associated with chronic alcohol abuse.
Mice with chronic alcohol use had significantly reduced levels of IL-10 in the amygdala and neurons didn’t fire properly. These factors led to increased alcohol consumption.
By boosting IL-10 signaling in the brain, however, the scientists reversed the unwanted effects from excessive drinking. In particular, they noticed a large decreased in anxiety and the desire to drink alcohol.
“We’ve shown that inflammatory immune responses in the brain are very much at play in the development and maintenance of alcohol use disorder,” Roberto says. “But perhaps more importantly, we provided a new framework for therapeutic intervention, pointing to anti-inflammatory mechanisms.”
Alcohol use disorder affects around 15 million Americans, and treatment options are slim, unfortunately. This study may lead to more therapies in the future, however, for those suffering from alcoholism. The key lies in boosting anti-inflammatory mechanisms in the brain, as high inflammation appears to exacerbate the problem.
Know the main red flags for alcohol use disorder (AUD)
According to the Mayo Clinic, here are key signs that someone may have alcohol use disorder:
- Not able to limit the amount of alcohol consumed
- Attempts to cut down on alcohol intake have failed, despite the desire to do so
- Devotes much of their time to drinking, obtaining alcohol, or recovering from hangovers
- Feels a strong urge or desire to drink excessively
- Work, school, or home life suffers due to alcohol abuse
- Continues to drink alcohol despite physical, social, or mental problems
- Withdraws from social or work activities and hobbies
- Drinks in unsafe situations, such as while driving or operating machinery
- High tolerance to alcohol, so more is needed to produce the desired effect
- Experiences withdrawal symptoms — such as nausea, sweating, and shaking — when they don’t drink, or drinking to avoid these symptoms
Heavy drinking can cause the following health problems over time:
- Liver disease. Heavy drinking can cause fatty liver disease, inflammation of the liver, and cirrhosis.
- Digestive problems. Alcohol abuse can lead to inflammation of the stomach lining, as well as ulcers. It can also cause malabsorption of necessary nutrients. Furthermore, it may cause pancreatitis (inflammation of the pancreas).
- Heart problems. Excessive drinking can lead to high blood pressure and eventually cause a heart attack or stroke. Just one episode of heavy drinking can cause heart arrhythmia.
- Worsens diabetes. Alcohol may cause low blood sugar because it disrupts the release of glucose from your liver. If you have diabetes and take insulin to lower your blood sugar, this can have dangerous implications.
- Neurological complications. Alcohol abuse can damage your nervous system, causing numbness and pain in your extremities, memory problems, dementia, and difficulty thinking clearly.
- Weakened immune system. Excessive alcohol intake can make it harder for your body to fight off diseases due to disruption in gut bacteria.
- Increased risk of cancer. Long-term, excessive alcohol use can increase the risk of many cancers, including mouth, throat, liver, esophagus, colon, and breast cancers.
Further findings from the study
In the study referenced above, Roberto and her team collaborated with Silke Paust, Ph.D., associate professor in the Department of Immunology and Microbiology. Paust and her team found increased levels of immune cells known as microglia and T-regulatory cells in mice with chronic alcohol use. These immune cells produce IL-10, the anti-inflammatory protein.
However, while the mice had higher levels of IL-10 in their brains overall, the amygdala showed much lower levels.
In the amygdala of mice with alcohol abuse, the signaling of the proteins didn’t function properly. This suggests that the immune system in the amygdala, specifically, responds differently to an alcohol use disorder.