Young people’s blood plasma rejuvenates old mice.

New Scientist has an anti-aging discovery with some grisly ramifications, as researchers find the blood of human teens can make aging bodies young again:

The key to youth appears to be in the blood plasma – the liquid part of blood. Several studies have found that injecting plasma from young mice into old mice can help rejuvenate the brain and other organs, including the liver, heart, and muscle.

Could blood plasma from young people have the same benefits? To find out, [Alkahest researcher Sakura] Minami and her colleagues took blood samples from 18-year-olds, and injected them into 12-month-old mice. At this age, the equivalent of around age 50 for people, the mice start to show signs of ageing – they move more slowly, and perform badly on memory tests.

The mice were given twice-weekly injections of the human plasma. After three weeks of injections, they were submitted to a range of tests. The treated mice’s performance was compared to young, 3-month-old mice, as well as old mice who had not received injections.

The team then examined the brains of the treated and untreated mice. They looked for clues on the birth of new neurons in the hippocampus – a process called neurogenesis, which is thought to be important for memory and learning. Sure enough, the treated mice appeared to have created more new cells in their brain. “Young human plasma treatment can increase neurogenesis,” says Minami.

Minami says she has identified some factors in young blood that might be responsible for these benefits, but that she won’t reveal what they are yet.

[via Ms Emmett]