The life-saving act of giving blood may not only be beneficial to the patient but also to the donor, researchers have suggested, because frequent donations encourage the body to produce fresh blood cells – boosting healthier and more resilient cells.
That’s according to scientists at the Francis Crick Institute in London, who found, in a collaborative global study, that regularly donating blood could lead to a subtle genetic change that reduces the risk of developing blood cancers.
Normally, blood-forming stem cells mutate as we age, which in some cases can increase the risk of diseases, including leukaemia.
However, the large study, published in the journal Blood, identified a surprising difference in the blood of people who regularly donated, The Independent reports.
Researchers compared the blood from two groups of healthy male donors – one group donated blood three times a year for 40 years, and the other only donated five times in total.
Although both groups had a similar number of genetic mutations, almost 50% of the group that donated thrice yearly carried a mutation not linked to cancer. That’s in comparison to just 30% of the group that donated less.
The researchers suggested that each time a person gives blood, the body produces fresh blood cells, which can alter stem cells in a beneficial way.
In laboratory experiments, the blood mutations seen in the men who gave blood were different to those associated with leukaemia.
Researchers injected the stem cells from frequent donors and found they were more effective at producing red blood cells than the stem cells from those who did not donate as frequently.
But further research is needed to determine whether donating blood actively reduces cancer risk.
Michelle Spear, professor of anatomy at the University of Bristol, explained in The Conversation: “Each time a person donates blood, the body quickly begins the process of replacing lost blood cells, triggering the bone marrow to generate fresh ones. This natural renewal process may contribute to healthier, more resilient blood cells over time.”
Previous research has also linked donating blood to a reduced risk of type 2 diabetes and heart disease.
Spear added that research has suggested blood donation can also increase insulin sensitivity, potentially reducing the risk of type 2 diabetes.
Regular blood donation could also help to reduce blood viscosity. This can make it easier for the heart to pump blood around the body and lower the risk of cardiovascular problems, said Adam Taylor, professor of anatomy at Lancaster University.
Donating blood “definitely has health benefits for the donor”, Taylor said.
“As the study shows, removing cells from the body by giving blood reduces the risk of mutations accumulating and causing disease,” he added.
However, he suggested another reason that donating blood has health benefits is because every time someone gives blood, they are given a mini health screening. As a result, conditions, including infectious diseases, are picked up earlier.
Study details
Clonal haematopoiesis landscape in frequent blood donors
Darja Karpova, Hector Huerga Encabo, Elisa Donato et al.
Published in Blood on 11 March 2025
Donor blood saves lives, yet the potential impact of recurrent large-volume phlebotomy on donor health and hematopoietic stem cells (HSCs) remains largely unexplored. In our study, we conducted a comprehensive screening of 217 older male volunteer donors with a history of extensive blood donation (>100 life-time donations) to investigate the phenomenon of clonal haematopoiesis (CH). No significant difference in the overall incidence of CH was found in frequent donors (FD) compared to sporadic donors (<10 life-time donations, 212 donors). However, upon deeper analysis of mutations in DNMT3A, the most commonly affected gene in CH, we observed distinct mutational patterns between the FD and age/sex matched control donor (CD) cohorts. Functional analysis of FD enriched DNMT3A variants examined in CRISPR-edited human HSCs demonstrated their competitive outgrowth potential upon stimulation with erythropoietin (EPO), a hormone which increases in response to blood loss. In contrast, clones harbouring leukaemogenic DNMT3A R882 mutations increase upon stimulation with IFNy. Through concurrent mutational and immunophenotypic profiling of primary samples at single cell resolution, a myeloid bias of premalignant R882 mutant HSCs was found, while no significant lineage bias was observed in HSCs harbouring EPO responsive DNMT3A variants. The latter exhibited preferential erythroid differentiation when persistent erythropoietic stress was applied to CRISPR-edited human HSC xenografts. Our data demonstrate a nuanced ongoing Darwinian evolution at the somatic stem cell level, with EPO identified as a novel environmental factor that favours HSCs carrying certain DNMT3A mutations.
Blood article – Clonal Haematopoiesis Landscape in Frequent Blood Donors (Creative Commons Licence)
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