It's not just what you eat, it's what's eating you
Restricting how much you eat without starving has been shown to robustly extend lifespan in more than 20 species of animals including primates. How this works is still unclear. In a new study published in PLOS Genetics, neuroscientists from Florida Atlantic University show that it's not just what or how much you eat that matters. Smelling food in addition to consuming calories could influence the aging process. And, what's "eating" you or more specifically your cells may provide clues to healthy aging.
Using a tiny worm called C. elegans, these researchers are the first to demonstrate how autophagy, a garbage disposal-like process where cells "eat" debris they produce through basic metabolism, combined with food absorption through the gastrointestinal (GI) tract and food smell through olfactory neurons impact the aging process mainly by diet restriction.
This study reveals that autophagy is an essential component in a neuroendocrine pathway that allows sensory neurons and nutrient levels to work together to influence lifespan. It also reduces the insulin growth factor signaling pathway, part of a complex system that cells use to communicate with their physiologic environment.
"The Cell Non-autonomous Function of ATG-18 is Essential for Neuroendocrine Regulation of Caenorhabditis elegans Lifespan," PLOS Genetics (2017).
With disease, when you decrease autophagy the disease process is exacerbated and when you increase it you get the opposite effect. Aggregation of polyglutamine expansion protein is a hallmark of Huntington's disease and other neurodegenerative diseases. The picture shows that there are more aggregates of green fluorescence protein-labelled polyglutamine expansion protein in autophagy deficient worms (right) compared to normal animals (left). Credit: Florida Atlantic University
