A study has found found that even very small amounts of ethanol, the type of alcohol found in alcoholic beverages, can more than double the life span of a tiny worm known as Caenorhabditis elegans.
The worms normally live for about 15 days and can survive with nothing to eat for roughly 10 to 12 days. But it survive 20 to 40 days when treated with tiny amounts of ethanol.
"This finding floored us - it's shocking," said Steven Clarke, a UCLA professor of chemistry and biochemistry and the senior author of the study.
And if the worms are given much higher concentrations of ethanol, they experience harmful neurological effects and die, other research has discovered.
"We used far lower levels, where it may be beneficial," said Clarke, who studies the biochemistry of aging.
The worms, which grow from an egg to an adult in just a few days, are found throughout the world in soil, where they eat bacteria. Clarke's research team studied thousands of these worms during the first hours of their lives, while they were still in a larval stage.
"Our finding is that tiny amounts of ethanol can make them survive 20 to 40 days," Clarke said.
The scientists fed the worms cholesterol, and the worms lived longer, apparently due to the cholesterol. They had dissolved the cholesterol in ethanol, often used as a solvent, which they diluted 1,000-fold.
"It's just a solvent, but it turns out the solvent was having the longevity effect," Clarke said.
"The cholesterol did nothing. We found that not only does ethanol work at a 1-to-1,000 dilution, it works at a 1-to-20,000 dilution. That tiny bit shouldn't have made any difference, but it turns out it can be so beneficial.
"The concentrations correspond to a tablespoon of ethanol in a bathtub full of water or the alcohol in one beer diluted into a hundred gallons of water," Clarke explained.
But the team could not explain why would such little ethanol have such an effect on longevity.
"We don't know all the answers," Clarke acknowledged. It's possible there is a trivial explanation, but I don't think that's the case. We know that if we increase the ethanol concentration, they do not live longer. This extremely low level is the maximum that is beneficial for them," he added.
In follow-up research, Clarke's laboratory is trying to identify the mechanism that extends the worms' life span.
About half the genes in the worms have human counterparts, Clarke said, so if the researchers can identify a gene that extends the life of the worm, that may have implications for human aging.
The study has been published Jan. 18 in the online journal PLoS ONE, a publication of the Public Library of Science.