For nearly two decades, researchers have been demonstrating in mice that the blood of a young animal, when surgically shared with an old one, can reverse signs of aging across nearly every tissue — heart, brain, muscle, liver, kidney — and the search for the specific factors in young blood that cause this effect has now become one of the most heavily funded races in modern biotech

The technique is called heterochronic parabiosis, and it works by surgically joining the circulatory systems of two animals of different ages so that they share a common blood supply. The procedure was pioneered by the French physiologist Paul Bert in the 1860s, originally as a way to study organ transplantation, and lay largely dormant in [...] The post For nearly two decades, researchers have been demonstrating in mice that the blood of a young animal, when surgically shared with an old one, c