How little ethanol is that?
"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 said.
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."
The scientists found that when they raised the ethanol level by a factor of 80, it did not increase the life span of the worms.
The research raises, but does not answer, the question of whether tiny amounts of ethanol can be helpful for human health. Whether this mechanism has something in common with findings that moderate alcohol consumption in humans may have a cardiovascular health benefit is unknown, but Clarke said the possibilities are intriguing.
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.
"It is important for other scientists to know that such a low concentration of the widely used solvent ethanol can have such a big effect in C. elegans," said lead author Paola Castro, who conducted the research as an undergraduate in Clarke's laboratory before earning a bachelor's degree in biochemistry from UCLA in 2010 and joining the Ph.D. p
|Contact: Stuart Wolpert|
University of California - Los Angeles