A new study by researchers at the Yale School of Medicine found that lab mice could live up to 40 percent longer when a hormone, FGF21, was increased in their bodies.
"Our research team is the first to show that FGF21 is a potential target for enhancing T cell function in the elderly and in cancer patients that undergo bone marrow transplantation," lead study author Vishwa Deep Dixit, Ph.D., a professor at the Yale School of Medicine, told CBS News.
FGF21 is created inside the liver as an endocrine hormone, but it is also found in the thymus, an organ that manufactures important T cells that fight infection in the body.
But as people -- and mice -- age, the thymus becomes fatty and loses its capacity to produce new T cells, which means a greater risk of infections and specific types of cancers in older people, according to a press release by Yale University.
The study, which was published in the medical journal Proceedings of the National Academy of Sciences on Jan. 11, found that after increasing FGF21 in older mice, their thymus organs were able to create new T cells, which extended the overall life spans of the rodents by 40 percent.
"If the average lifespan is 80 years in humans, and if FGF21's effects from mice translate into humans, FGF21 may add approximately 30 years to life," Dixit told CBS News. "But this is speculative at this time."
"The early stage research discoveries require several years to be translated in humans," Dixit added. "Substantial research funding and time is required to test the efficacy of FGF21 on immune function in the elderly and cancer patients. It is difficult to predict this at this time."
FGF21 is also a metabolic hormone that can contribute to weight loss and improve insulin sensitivity. That's why the hormone is also being studied for possible treatment options in Type 2 diabetes and obesity.