Transfusions of young blood could hold key to longer life, scientists say

Researchers hope the blood of the young could contain the key to longer life after finding that a substance circulating in the veins of juvenile mice delayed death and kept disease at bay.

US researchers, led by the University of Washington, found that one compound which is abundant in the blood of young mice, an enzyme known as eNampt, extended lifespan by 16 per cent when transferred to older rodents.

“We have found a totally new pathway towards healthy ageing,” said Dr Shin-ichiro Imai, who was a senior author of the study, published in the journal Cell.

“That we can take eNampt from the blood of young mice and give it to older mice and see that the older mice show marked improvements in health – including increased physical activity and better sleep – is remarkable.”

The researchers gave each group of mice either an oral dose of the enzyme or a control of saline solution, and differences were “dramatic” between the groups.

Animals receiving the treatment produced insulin more effectively, had healthier eyes, performed better in memory tests, spent longer on their wheel and grew “thicker, shinier fur”, the authors said.

While none of the control group lived beyond 2.4 years, one of the mice treated with eNampt was still alive as the paper was being written – 2.8 years later.

This extra lifespan could be directly predicted by measuring levels of eNampt in the blood.

The findings could offer another hopeful avenue in a wave of research into “anti-senolytic” treatments.

These work by aiming to mop up old “zombie cells” which can contribute to conditions of old age like sight loss, heart disease, diabetes and cancer.

Because it is so fundamental to every living thing, evolution has developed a host of support process to ensure adequate levels of ingredients needed to turn sugars and oxygen into the energy molecule, ATP.

In the case of eNampt it helps produce a chemical called NAD which is part of this cycle. While eNampt’s effects haven’t been studied in people, human trials are already underway for another chemical which performs a similar role and helps rejuvenate the construction of new blood vessels.

“We think the body has so many redundant systems to maintain proper NAD levels because it is so important,” Dr Imai said.

“Our work and others’ suggest it governs how long we live and how healthy we remain as we age. Since we know that NAD inevitably declines with age, whether in worms, fruit flies, mice or people, many researchers are interested in finding anti-ageing interventions that might maintain NAD levels as we get older.”