Reducing Glycerol and Glyceraldehyde Levels Extends Life in Nematodes

Researchers here note an approach to extending life by 50% in nematode worms that functions by lowering levels of glycerol and glyceraldehyde in tissues. Lower animals such as nematodes have a far greater plasticity of life span in response to interventions than is the case for mammals. Thus this research is worth taking note of, a suggestion that this area of metabolism is worthy of more attention, but implementing something similar in mammalian species should not be expected to do more than modestly slow aging.

Glycerol and glyceraldehyde are harmful by-products of fat that naturally accumulate over time. Prior aging research in worms, mice, and human cells made researchers in the field suspect that the key to extending lifespan was to activate autophagy, a process that renews broken and old parts in our cells. But researchers were surprised to find that wasn't necessary - the scientists improved worm health and lifespan by 50% with no increase in autophagy at all. They did this by increasing expression a particular gene, adh-1. Doing so prompted the gene to produce more of an enzyme, alcohol dehydrogenase, that prevented the toxicity caused by glycerol and, indirectly, glyceraldehyde. The result was that the worms lived longer, healthier lives.

Findings in lab models such as worms and mice don't always hold true in people, of course. So the researchers took several more steps to see if their lead was as promising as it appeared. First, they confirmed that the enzyme had similar beneficial effects on lifespan in another lab model, yeast. Then they scoured through research looking at gene activity in creatures, including humans, who had undergone fasting or calorie restriction because both fasting and calorie restriction are known to extend healthspan and lifespan. Sure enough, the scientists found increased levels of the anti-aging enzymes in all the mammals tested, including in humans.

The scientists suspect that our levels of glycerol and glyceraldehyde naturally increase over time because they are toxic byproducts of fat, which we store more of as we age. Thus, this approach may offer a way to head off the fat-derived toxicity, extend the number of years we live in good health, and maybe help us shed some extra pounds, too.