Longevity Briefs: Can We Improve Longevity Simply By ‘Diluting’ The Blood?

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: In 2005, Irina Conboy and her team made a surprising and ground-breaking discovery. Connect the circulatory systems of and old mouse and a young mouse so that they could freely exchange blood, and the old mouse would be rejuvenated at the cellular level. Later experiments confirmed that infusions of ‘young blood’ could rejuvenate old mice, while infusions of ‘old blood’ made young mice age faster.

More recently, another surprising discovery was made: merely diluting the blood of older animals had similar rejuvenating effects to young blood infusions. This suggested that the effects of young blood infusions are largely due to the dilution of molecules in the plasma (the non-cellular part of the blood) that promote ageing, rather than the addition of molecules that reverse it. Dilution is fairly easy to do in humans, but we need clinical trials to investigate what its effects are, if any, on the ageing process.

What did the researchers do: A new company called Lyfspn is planning a clinical trial to investigate the possible health benefits of blood plasma dilution in humans. The trial will be led by Dr Dobri Kiprov, a recognized expert in the field of apheresis (the separation of specific components from the blood). They hope to enrol 40 participants aged 50 to 85 in a randomised, placebo-controlled clinical trial. Since infusion with human plasma can sometimes cause severe reactions, they will instead be using 5% human albumin, a protein made by the liver and hypothesised to contribute to health decline when modified during the ageing process. They plan to test a variety of schedules that range from one treatment per month to up to two treatments per week, and repeating the program for a period of three months.

Key takeaway(s) from this research: This trial should provide some much needed evidence about whether plasma dilution can improve human health. More details on the trial will hopefully be available soon. Of particular interest will be the effects on inflammation and on the immune system, which appears to function better after apheresis and may play a significant role in the proposed health benefits.