The secret of eternal youth has long been the stuff of fantasy novels, and while modern medicine is keeping us alive for longer, we still grow old and suffer from the usual ailments associated with old age.
But researchers have discovered that an infusion of ‘new blood’ from a younger person can begin to rejuvenate the host.
Joined at the hip
It all began in 2005 when – in a rather gruesome procedure called parabiosis – scientists attached two mice together; a young mouse and an older mouse. The creatures’ blood vessels merged, so they shared the same circulatory system, and the blood of the young mouse was combined with that of his aging partner. Then an extraordinary thing happened: the old mouse began to show signs of growing younger.
The mouse was able to repair muscle injuries more easily, and its liver, nervous and skeletal systems showed the same signs of regeneration. It was also healthier and more active. Further research has since shown that the older mice also experience a burst of brain cell growth, some three to four times the level of similarly aged mice. However it wasn’t such good news for the young mouse, which displayed signs of accelerated decrepitude, to borrow a phrase from Blade Runner. It’s as if the old mouse was leaching the life out of the youngster.
The theory behind these results is that the young blood is able to restore the ageing stem cells’ ability to reproduce and mend broken tissue. It’s also possible that the older mouse was benefiting from the use of the youngster’s liver and kidneys; a transfusion of young blood showed similar effects, but they weren’t as pronounced as with parabiosis.
So much for mice, but what about people? Recent trials have suggested that young blood plasma injected into people aged 35 and above has had a marked effect on the biological markers (specific proteins and antigens) related to Alzheimer’s, cancer and heart disease.
Food and drink of the gods
A US company called Ambrosia (from the Greek ‘immortality’) is currently testing 600 people before and after transfusion. The blood plasma is purchased from blood banks – where it’s often a by-product of blood transfusions – and those treated are already reporting improved muscle strength and energy levels. However, before you go rushing to sign up, a one-litre treatment will set you back $8,000!
A different approach to anti-aging is to enhance a person’s DNA protectors, called telomeres. A telomere is a nucleotide sequence that protects the ends of chromosomes from deterioration. As cells repeatedly divide, so the telomeres become shorter and shorter until they can no longer do their job and the cells become inflamed or begin to die.
Scientists in Spain have extended the lifespan of telomeres in mice using gene therapy, with the result that the mice lived 40% longer than usual. Some academics think the treatment could also extend the life of damaged cells, leading to cancer, but that hasn’t stopped another US company called BioViva from offering the gene therapy treatment to humans.
Who wants to live forever?
So on the face of it, the answer to the original question is yes: young blood does seem to have some regenerative effects on older people. But with a world population hurtling towards 8 billion, mass unemployment and societies unable to cope with aging populations, perhaps that’s not the question we should be asking…