Donating blood might seem like a purely altruistic endeavor, but emerging research suggests that frequent blood donors may actually reap significant health benefits themselves. For years, there has been speculation regarding the potential protective effects of blood donation against heart attacks and strokes. Recent studies indicate that regular blood donors may also have a reduced risk of developing leukaemia, a type of cancer that affects the blood and bone marrow.
Leukaemia arises when the cells in the bone marrow, responsible for producing immune cells and red blood cells, begin to multiply uncontrollably. To investigate this phenomenon, researchers conducted a study involving older German men who had donated blood at least 100 times throughout their lives, comparing them to a similar cohort who had donated infrequently.
Findings on Immune Cells and Genetic Mutations
The study focused on the genetic mutations of immune cells in both groups. As Dr. Hector Huerga Encabo, the lead researcher from The Francis Crick Institute in London, explained, “Cells acquire mutations naturally as they divide.” The findings revealed that while both groups exhibited genetic mutations, non-donors had mutations that are linked to an increased likelihood of developing leukaemia.
In contrast, the frequent blood donors displayed fewer “pre-leukaemia” mutations, and interestingly, they possessed mutations that enhanced their bone marrow’s ability to replenish red blood cells. Dr. Huerga Encabo noted, “This suggests a potential link between regular blood donation and a decrease in pre-leukaemia mutations.” The results of this study have been published in the medical journal Blood.
Previously, there were concerns that frequent blood donation might elevate the risk of leukaemia by promoting excessive multiplication of bone marrow cells, potentially leading to cancerous mutations. However, this new research indicates that regular blood donation may actually steer bone marrow cells towards producing healthy red blood cells rather than following a cancerous trajectory.
Dr. Lise Estcourt, NHS Blood and Transplant Medical Director for Transfusion, commented on the study, stating, “While the findings are intriguing, the sample size is small, and additional research is necessary before drawing definitive conclusions.” She emphasized that the study implies that regular blood donation does not cause harmful genetic changes and may promote the generation of healthy red blood cells.
Further supporting these findings, a prior study from Sweden indicated that blood donors had a 15% lower incidence of acute myeloid leukaemia (AML) compared to those who rarely donated blood. Although blood donors showed a 7% increased risk for a less common type of leukaemia called chronic lymphocytic leukaemia (CLL), the overall evidence suggests that blood donors experience a lower risk of leukaemia.
Potential Benefits for Heart Health
In addition to its potential role in reducing leukaemia risk, blood donation may also offer protective effects against heart disease and strokes. This could be due to the reduction in blood viscosity, making the remaining blood less prone to clotting. While this theory remains to be confirmed, a review conducted in 2022 found that nine studies indicated a lower risk of heart disease among blood donors, while five studies reported no significant difference.
For individuals with a genetic condition known as haemochromatosis, which leads to elevated iron levels in the body, blood donation is particularly beneficial. Elevated iron can cause severe damage to the liver, heart, and joints, potentially leading to early mortality. The recommended treatment for haemochromatosis includes regular blood donation, sometimes as frequently as every six weeks, to help reduce iron levels. In contrast, individuals without this condition are advised to donate blood every three months if they are male and every four months if they are female, according to NHS guidelines.
In the UK, approximately 1 in 100 individuals are diagnosed with haemochromatosis, although the actual prevalence may be higher due to the lack of screening. Among newly diagnosed patients, many are often surprised to find that their joint pain alleviates after regular blood donations, indicating they may have unknowingly been managing their condition.
For most individuals, the side effects of blood donation are typically mild and temporary, including slight fatigue or dizziness due to a minor drop in blood pressure, which usually normalizes within a few hours. However, for those receiving blood transfusions—such as individuals recovering from surgery, childbirth, or illnesses like cancer—the impact can be life-saving.
