A new study found that the Oriental hornet is the only known animal capable of consuming alcohol chronically and in high concentrations with almost no negative effects.
The research was conducted under the leadership of postdoctoral fellow Sofia Bouchebti from the laboratory of professor Eran Levin of Tel Aviv University’s School of Zoology and the Steinhardt Museum of Natural History. The study was published in the journal “Proceedings of the National Academy of Sciences of the United States of America (PNAS).”
“The hornets naturally store yeasts in their digestive system, which provides them with a unique environment that allows the yeast to develop and reproduce, creating new strains,” explained Bouchebti. “In our study, we labeled the alcohol consumed by the hornets with a heavy carbon isotope. As the alcohol is metabolized, it breaks down into carbon dioxide, which is exhaled. By measuring the amount of labeled carbon dioxide emitted, we were able to estimate the speed at which the alcohol was broken down. The findings were very surprising; we were amazed to see the rapid rate at which the hornets metabolized the alcohol.”
In the next stage, the researchers sought to determine whether the Oriental hornet ever becomes intoxicated. Here too, the findings were surprising: Even when consuming high concentrations of alcohol (80% alcohol as the sole source of nutrition) there was no noticeable effect on the hornets’ behavior.
In the final phase of the study, the researchers tested whether alcohol had any impact on the hornets’ lifespan and health. Once again, they were amazed to discover that no differences were found between the lifespan of hornets that consumed only alcohol for their entire lives (three months) and hornets that consumed sugar water.
Alcohol is commonly produced in nature through the breakdown of sugars by yeasts and bacteria, primarily found in ripe fruits and nectar. Alcohol is toxic to most animals—including humans—with occasional consumption, and especially with chronic use.
Among the animals known to consume alcohol are fruit flies, which show signs of alcohol poisoning even at relatively low concentrations, and tree shrews—mammals native to East Asia that feed on ripe, alcohol-rich fruits—who show symptoms such as fatty liver and other effects indicative of alcoholism even after consuming low concentrations of the substance continuously for several days.
“To the best of our knowledge, Oriental hornets are the only animal in nature adapted to consuming alcohol as a metabolic fuel. They show no signs of intoxication or illness, even after chronically consuming huge amounts of alcohol, and they eliminate it from their bodies very quickly,” said Levin.
In a bioinformatics analysis of the Oriental hornet’s genome, conducted by professor Dorothee Huchon, it was discovered that the hornet possesses several copies of the gene responsible for producing the enzyme that breaks down alcohol; this genetic adaptation may be related to their incredible ability to handle alcohol.
The scientists proposed that the ancient relationship between hornets and yeast led to the development of this adaptation. They expressed hope that research into Oriental hornets could potentially be used to develop new models for studying alcoholism and the metabolism of alcohol.