Does plasma exchange (plasmapheresis) work against ageing?
There are initial, cautiously positive indications from one small study, but it is too small and too influenced by commercial interests to draw any conclusions at this stage. Wait for larger, independent studies before considering this treatment.
Blood plasma contains substances that appear to promote ageing as well as substances that protect against it. Animal experiments involving blood exchange show that this can affect the brain, blood vessels and immune system. A large study of more than 4,000 people identified 38 proteins in the blood that predict the risk of dementia, sometimes as much as twenty years in advance. That makes the biological rationale behind plasma exchange understandable, but it does not yet prove that removing those substances actually works.
The only randomised study in humans was very small: 42 healthy adults aged 50 and over. Participants who received plasma exchange every two weeks, combined with an infusion of antibodies, scored better on fifteen different measures of biological age than the placebo group. That sounds promising, but a study this small provides preliminary indications, not proof. In addition, several of the lead authors are co-founders of a commercial company that has a financial interest in this treatment. That makes independent replication all the more necessary.
On safety: in that same small study, two participants had to withdraw due to side effects, one of which was attributable to the antibody infusion. No serious safety problems were reported, but with so few participants, rare side effects cannot be reliably ruled out. Plasma exchange is also an invasive medical procedure that is normally used for serious diseases.
In liver failure, plasma exchange helped stabilise blood pressure but did not improve survival in a group of 378 patients. In a serious blood disorder, the procedure turned out to be replaceable by medication alone. This shows that positive effects on blood values or biomarkers do not automatically translate into real health gains, even for diseases in which TPE has already been used for some time.
One small RCT (n=42) in healthy older adults with commercial interests among the authors; one review study on animal experiments; one large proteomics study (n=4,110) on plasma proteins and dementia risk; two clinical studies in acute liver failure and a blood disorder (not on ageing). Animal model study not relevant to clinical effectiveness.