July 26, 2019. Research described on July 25, 2019 in Cellfound an association between a slower metabolic rate and a reduction of potentially damaging effects of genetic mutations. The finding could help explain the link between calorie restriction, which slows metabolism, and longer life.
By halving the metabolic rate of fruit flies, Northwestern University researchers observed that the anticipated harmful effects of many mutations failed to manifest. “When the flies developed at a normal rate, developmental problems occurred,” stated lead researcher Richard Carthew. “When we slowed the rate, developmental problems disappeared. They develop slower and grow slower, but, otherwise, they are normal animals.”
“This upends the paradigm of everything we know about development,” added coauthor Luís Amaral. “We have always thought that if you ‘break’ some genes, there will be serious developmental consequences. It turns out that’s not true for some genes — as long as you also slow the metabolism of the growing organism.”
While it had been believed that microRNAs were necessary for survival, the researchers discovered that fruit flies that lacked microRNAs survive to normal adulthood when their metabolic rate is reduced. “Our result concludes that this entire family of gene regulators is not essential,” Dr Carthew observed.
Drs Carthew and Amaral suggest that slower metabolism gives the body more time to correct errors. “When you look at all the different proteins and genes that interact within a cell, you can get overwhelmed by all the components and the interactions among them,” Dr Amaral stated. “If you are growing fast and something goes wrong, it can be catastrophic. You need these complex networks because they increase redundancy to prevent catastrophe. But if you are growing slowly, you might not need such a complex system. You have more time to adjust to mistakes and react to changes.”