BETHESDA, Md. — The old adage claiming alcohol “goes straight to the head” is actually true according to new research. Scientists say booze breaks down in the brain, rather than the liver.
The finding turns previous theories upside down and scientists believe it holds the key to combating binge drinking and alcoholism. Researchers hope the results could also one day be used to treat conditions such as strokes, Parkinson’s disease and multiple sclerosis.
“Alcohol metabolism may be regulated directly in the brain,” says lead author Dr. Li Zhang, of the National Institute on Alcohol Abuse and Alcoholism, in a statement per SWNS media. “It suggests the possibility of new targets for altering the effects – and potentially treating alcohol use disorder.”
The study sheds fresh light on why people can get tipsy after only one or two drinks. The response can trigger unsteadiness, slurred speech and slower reaction times.
“Alcohol suppresses human brain function and affects behavior,” says Zhang. “The possibility of brain alcohol metabolism has been a controversial topic within the field for several decades.”
But little is known about the neurological processes that control the action of metabolites in the brain. The behavioral effects are caused by metabolites made as the body breaks down beer, wine or spirits. One such chemical, acetate, is produced by an enzyme called ALDH2, which is abundant in the liver.
But tests on human brain samples and mice showed it’s also expressed in specialized brain cells known as astrocytes. They have been described as the tiles of the central nervous system and are found in the cerebellum, the brain region that controls balance and coordination.
When ALDH2 was removed from the cells, the lab rodents became immune to motor impairments induced by alcohol consumption. They performed as well as their peers on a rotating cylinder, or “rotarod,” that measures their balance and coordination skills.
“There’s a long-standing idea brain acetate derives largely from liver alcohol metabolism,” says Zhang. “Indeed, acetate can be transported through the blood–brain barrier with a high capacity. “Our data presented here directly challenge this idea. They suggest the central but not the peripheral alcohol metabolic pathway produces acetate.”
Drinking fuels the metabolite and GABA, a neurotransmitter that calms the nerves and causes sleepiness. Thought, speech and movements slow up as different parts of the brain cannot coordinate. It’s why we slur our words, fail to pick up on social signals, can’t make decisions and become clumsy.
“But this elevation was prevented when ALDH2 was deleted from astrocytes. In contrast, removing ALDH2 in the liver did not affect the levels of acetate or GABA in the brain,” explains Zhang. “These findings suggest acetate produced in the brain and in the liver differ in their ability to affect motor function.”
The study published in Nature Metabolism opens the door to better regulation of the effects of drink on behavior.
It could lead to improved therapies for alcoholism and binge drinking and other conditions that reduce balance and coordination.
These range from stroke and Parkinson’s disease to multiple sclerosis.
“Astrocytic ALDH2 is an important target not only for alcohol use disorders but also for other neurological diseases,” says Zhang.
SWNS writer Mark Waghorn contributed to this report.