Mitochondria are known as the powerhouses of the cell; they act in concert to generate energy according to demand. These coordinated mitochondrial networks in cells tend to have less capacity as we age. New research has shown that alteration of mitochondrial networks, whether by restricting diet or by manipulating genes, may promote good health and lead to an increase in lifespan. The work, published in Cell Reports by scientists at the Harvard T.H. Chan School of Public Health, indicates how periods of fasting are likely to encourage healthy aging.
Changes in the how mitochondrial networks are shaped have been found have a causal linked to longevity. Nematode worms are often used to study aging; their lifespan is only a few weeks. Restricting diet in these worms kept the mitochondrial networks in a youthful state. When the scientists genetically manipulated a protein that senses energy, AMP-activated protein kinase (AMPK), it had the same effect. These young mitochondrial networks were found to increase lifespan by signaling to other organelles, peroxisomes, which altered fat metabolism.
"Low-energy conditions such as dietary restriction and intermittent fasting have previously been shown to promote healthy aging. Understanding why this is the case is a crucial step towards being able to harness the benefits therapeutically," explained the lead author of this work Heather Weir, who conducted the research while at Harvard Chan School and now works at Astex Pharmaceuticals. "Our findings open up new avenues in the search for therapeutic strategies that will reduce our likelihood of developing age-related diseases as we get older."
The video features a lecture from Dr. Matt Piper, University College London, Institute of Healthy Ageing on aging and diet.
"Although previous work has shown how intermittent fasting can slow aging, we are only beginning to understand the underlying biology," noted William Mair, senior study author and Associate Professor of Genetics and Complex Diseases at Harvard Chan School. "Our work shows how crucial the plasticity of mitochondria networks is for the benefits of fasting. If we lock mitochondria in one state, we completely block the effects of fasting or dietary restriction on longevity."
The researchers now plan to investigate the role of the mitochondrial networks in fasting in mammals. They want to know whether mitochondrial flexibility defects may help explain why the risk of age-related diseases is heightened in the obese.