It is a well known that side effects of heavy drinking can often lead to impaired brain activity, poor motor skills and even changes in behaviour. But a new study from Yale University suggests that heavy drinking may actually accelerate the body’s ability to turn alcohol into energy-boosting acetate, especially in the brain.
The findings may have implications for treating alcohol withdrawal in addicts, and researchers say they also prove that the brain is constantly adapting and developing according to its environment and intakes.
When people consume drinks such as beer or wine, their liver breaks down the compounds and turns them into acetate, which is then distributed throughout the body, into the bloodstream and to the brain. This is similar to the way our bodies convert carbohydrates into sugar and stores them for energy. So, with this in mind, the study’s co-author, Graeme Mason of Yale’s department of psychiatry, hypothesized that perhaps, if more acetate is delivered, then the brain may increase it’s ability to be turn it into energy.
In the study published this month in the Journal of Clinical Investigation, researchers compared the brain chemistry of heavy drinkers to light drinkers to determine a link between chronic heavy drinking and increased cranial activity.
Seven heavy drinkers, who regularly consumed at least eight drinks per week and at least four drinks per day at least once per week, were compared to seven light drinkers who had less than two drinks per week. Men who drank more than 14 drinks per week or women who drank more than eight drinks per week were recruited as heavy drinkers, and people who drank fewer than two drinks per week were recruited as light drinkers. Some of the light drinkers had gone as many as two months without a drink. All the subjects were between 21 and 46 years of age, healthy, and not alcohol dependent.
In order to interpret metabolic changes in the brain, researchers tested their blood-alcohol levels first and then administered the same levels of acetate for two hours. During that time, their reactions were scanned with a magnetic resonance spectroscopy machine (MRS) to determine the presence of natural N-acetylaspartate (NAA), C-labelled glutamate, glutamine and acetate.
In the initial tests, the heavy drinkers had higher levels of acidic compounds in their blood prior to infusion, compared to the light drinkers. By the study’s end, they found that heavy drinkers had ingested twice as much acetate into their bloodstreams than light drinkers (which is a testament to their body’s ability to do so). However, the heavy drinkers also tested for higher levels of glutamate, which is a neurotransmitter that aids in cognitive functions such as memory and learning in the brain, as well as glutamine which is often used in treatment of injuries, burns and trauma.
These findings are monumental as biochemical geneticist Ting-Kai Li of Duke University, tells sciencenews.org, since it was always believed the body could only use sugar as a form of energy, but Mason and his colleagues’ proven hypothesis shows the brain’s continuous development.
“I think it’s a very good hypothesis,” he said. According to Li, scientists have also long suspected that heavy drinkers ingest and burn more acetate, but Mason’s team has now proven that it’s “actually happening.”
The findings may also explain why tolerance levels are higher among heavy drinkers and why it so difficult for them to abstain from alcohol. Quitting drinking, as well as removing an addictive substance, would also be removing an energy source the brain can come to rely on. “Caloric reward” in turn, may encourage a heavy drinker’s continued alcohol abuse over time.
Mason hopes to use these findings to determine if acetate can be used as a sedative agent in reducing withdrawal symptoms of alcohol-dependents. Acetate is a primary element in vinegar, but he warns that drinkers should not start replacing their favourite beer with vinegar.
“I don’t want people to start chugging vinegar,” he says. Since the liver is so effective at turning alcohol into acetate, people would have to ingest quarts of vinegar to get as much acetate as they would from drinking alcohol.
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