New Blood, Slower Aging

Scientists have shown transfusing the blood of younger mice with older ones successfully extends the life span of older mice by almost 10%, according to new results published yesterday. The findings may help further understanding of biological anti-aging mechanisms, which could eventually be of use in humans.

The technique, known as heterochronic parabiosis, essentially ties two mice together for an extended period of time with their circulatory systems surgically connected. A main signature of aging is the inability of organs and tissues to regenerate and maintain their integrity. Younger blood has more components that assist this process; older blood has fewer.

The phenomenon has been known for decades (see overview); however, the new study is the first to show the length of the transfusion increases the length of the benefits, and to quantify the benefits to older mice.

Researchers said the results translate into about eight additional years added to a subject's life span if translated to humans.