Blood donation is widely recognised as a life-saving act, replenishing hospital supplies and aiding patients. But, could donating blood also benefit the donor? Frequent blood donors may experience subtle genetic changes that could lower their risk of developing blood cancers, according to new research from the Francis Crick Institute in London, England. Alongside this, a growing body of evidence highlights a range of health benefits associated with regular donation. As we age, our blood-forming stem cells naturally accumulate mutations, a process known as clonal haematopoiesis. Some of these mutations increase the risk of diseases such as leukaemia. However, the new study has identified an intriguing difference in frequent blood donors. The study compared two groups of healthy male donors in their 60s. One group had donated blood three times a year for 40 years, while the other had given blood only about five times in total. Both groups had a similar number of genetic mutations, but their nature differed. Nearly 50% of frequent donors carried a particular class of mutation not typically linked to cancer, compared with 30% of the infrequent donors. It is thought that regular blood donation encourages the body to produce fresh blood cells, altering the genetic landscape of stem cells in a potentially beneficial way. In laboratory experiments, these mutations behaved differently from those commonly associated with leukaemia, and when injected into mice, stem cells from frequent donors were more efficient at producing red blood cells. 

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.

Some evidence even suggests that blood donation could improve insulin sensitivity, potentially playing a role in reducing the risk of type 2 diabetes.

For years, scientists have speculated about a possible link between blood donation and cardiovascular health. One of the key factors in heart disease is blood viscosity — how thick or thin the blood is. When blood is too thick, it flows less efficiently, increasing the risk of clotting, high blood pressure and stroke. Regular blood donation helps to reduce blood viscosity, making it easier for the heart to pump and lowering the risk of cardiovascular complications.

There is also growing evidence that blood donation may help regulate iron levels in the body, another factor linked to heart disease. While iron is essential for oxygen transport in the blood, excessive iron accumulation has been associated with oxidative stress and inflammation, both of which contribute to heart disease. By shedding iron through donation, donors may be reducing their risk of these iron-related complications.

Some studies have even suggested a potential link between blood donation and lower blood pressure, particularly in people with hypertension. Though not a substitute for medication or lifestyle changes, donating blood may be another way to assist overall cardiovascular health.

Donors may not realise it, but, every time that they give blood, they receive a mini health screening. Before donation, blood pressure, haemoglobin levels and pulse are checked, and in some cases, screenings for infectious diseases are performed. While not a replacement for regular check-ups, it can serve as an early warning system for potential health issues.

Blood donors must meet strict eligibility criteria. People with chronic illnesses, certain infections or a history of cancer are usually not allowed to donate. This means that those who donate regularly may already be healthier than the general population.

(The Conversation)