Chinese scientists have made a discovery that could change our understanding of the factors that influence longevity. They have found that a bile acid produced by the liver, specifically lithocholic acid (LCA), has effects similar to calorie restriction, a commonly accepted method for improving longevity.
They found that LCA, which is produced by the liver, can enhance muscle regeneration, as well as increase grip strength and running ability.
Previous studies have shown that mammals accumulate LCA during calorie restriction, and it activates a key molecule involved in metabolism called AMP-activated protein kinase, or AMPK. It is activated when glucose levels drop and plays a key role in aging by regulating processes such as inflammation and nerve degeneration.
In experiments on fruit flies, the scientists found that LCA activates AMPK and produces anti-aging effects similar to calorie restriction. Since these animals do not synthesize LCA naturally, the scientists injected it into them. Depriving the animals of the ability to produce AMPK resulted in a loss of the effects of LCA when it was administered, confirming that the liver acid acted in an “AMPK-dependent manner.”.
The scientists took blood serum from mice that had been on a calorie-restricted diet for four months and injected it into rodents that were eating a regular diet. They found that the injected serum led to the activation of AMPK in the mice's liver and muscle.
The researchers also observed that administering LCA increased the average lifespan of the flies by four to five days.
Administration of “only the activated metabolite LCA may exert anti-aging effects,” the scientists concluded in the study.
“People have long been searching for a longevity elixir. LCA is one possibility because it is a single molecule in the blood of people who practice calorie restriction and activates AMPK, which in turn further induces changes in metabolites in the blood,” commented the study’s lead author, Lin Shengcai from Xiamen University.
