A life-extending hormone found in mice

  Science and Technology Daily, Beijing, May 17 (Reporter Zhang Mengran) A new study published in the journal "Nature Communications" by the Pennington Biomedical Research Center in the United States found that reducing the protein content in the diet will produce effects including prolonging life. A series of favorable health outcomes, and these effects depend on a metabolic hormone called fibroblast growth factor 21 (FGF21).

  Reducing intake is known to improve health and increase longevity, and there is growing interest in the possibility that reducing protein or amino acid intake could contribute to this beneficial effect.

Several recent studies have shown that diets that are low in protein, but not so low as to cause malnutrition, can improve health.

Conversely, excessive consumption of high-protein diets was associated with increased mortality in certain age groups.

  Several years ago, the Pennington Biomedical Research Center's Neural Signaling Laboratory discovered that the metabolic hormone FGF21 is a key signal that links the body to the brain during times of protein restriction.

Without this signal, young mice were unable to alter their feeding behavior or metabolism while on a low-protein diet.

  Dr Christopher Morrison, professor and director of the Neurosignaling Laboratory, said: "Our data suggest that FGF21 talks to the brain and without this signal the mouse would not 'know' it was eating a low-protein diet. As a result, the mouse could not adapt. Sexually alter its metabolism or feeding behavior."

  Studies have shown that a low-protein diet has beneficial metabolic effects in aged mice, improving metabolic health, reducing frailty and extending lifespan.

These beneficial effects were also evident when middle-aged mice reduced their protein intake, and even prevented the harm of obesity.

Importantly, these beneficial effects were lost in mice lacking FGF21, suggesting that its actions in the brain are critical for increased health and longevity.

  Previous research has shown that FGF21 acts in the brain to improve the metabolic health of young mice fed a low-protein diet.

The new data extend this study, which provides clear evidence that FGF21 is the first known hormone that coordinates feeding behavior and metabolic health to prolong life during a low-protein diet.

  The researchers hope this work will reveal novel molecular and neural pathways that can be used to improve human health.

"This groundbreaking research has important implications for ensuring people are healthy and living longer. If scientists can better understand how diet and nutritional hormones such as FGF21 prolong life, it could counteract many of the health problems that occur after middle age."