alternative_right shares a report from Phys.Org: In new research published by scientists studying fission yeastâ"a single-celled organism surprisingly similar to human cellsâ"researchers found that caffeine affects aging by tapping into an ancient cellular energy system. A few years ago, the same research team found that caffeine helps cells live longer by acting on a growth regulator called TOR (target of rapamycin). TOR is a biological switch that tells cells when to grow, based on how much food and energy is available. This switch has been controlling energy and stress responses in living things for over 500 million years. But in their latest study, the scientists made a surprising discovery: Caffeine doesn't act on this growth switch directly. Instead, it works by activating another important system called AMPK, a cellular fuel gauge that is evolutionarily conserved in yeast and humans. "When your cells are low on energy, AMPK kicks in to help them cope," explains Dr. Charalampos (Babis) Rallis, Reader in Genetics, Genomics and Fundamental Cell Biology at Queen Mary University of London, the study's senior author. "And our results show that caffeine helps flip that switch." Interestingly, AMPK is also the target of metformin, a common diabetes drug that's being studied for its potential to extend human lifespan together with rapamycin. Using their yeast model, the researchers showed that caffeine's effect on AMPK influences how cells grow, repair their DNA, and respond to stress -- all of which are tied to aging and disease. The study has been published in the journal Microbial Cell.Read more of this story at Slashdot.