Many Americans are surprisingly unfamiliar with their own blood type, despite its importance in more than just transfusions. A recent survey revealed that more people know their zodiac sign than their blood type—a telling statistic about priorities. However, understanding your blood type could offer significant insights into your overall health, especially when it comes to cardiovascular risks. Studies have linked certain blood types, such as A and B, to a higher likelihood of developing blood clots, heart attacks, and strokes compared to type O.
Blood type is determined by the presence or absence of specific antigens on the surface of red blood cells, which can trigger immune responses. There are four main blood types—A, B, O, and AB—with each categorized further by the presence (+) or absence (-) of the Rh factor. This results in eight distinct blood subtypes. Research published in 2020 highlighted the cardiovascular risks associated with type A and B blood, showing these individuals are significantly more likely to develop deep vein thrombosis or pulmonary embolisms compared to those with type O blood. The study also revealed modestly higher risks of heart attacks and heart failure for these groups.
The disparities in health outcomes by blood type can partly be explained by how blood type influences clotting factors. Experts point to the enzyme responsible for determining blood type, which also modifies the von Willebrand factor—a protein crucial for clot formation. People with type O blood tend to have lower levels of this protein, which correlates with a reduced risk of abnormal clotting. On the other end of the spectrum, individuals with AB blood have the highest von Willebrand factor levels, making them more prone to blood clots and associated complications.
Additional factors may also play a role. Some evidence suggests that type A blood is linked to higher levels of LDL cholesterol, the “bad” cholesterol that clogs arteries, while type AB blood may promote inflammation that harms blood vessels. Platelet activity, which influences clot formation, might also differ across blood types, further contributing to these risks. Though more research is needed to draw definitive conclusions, these findings underscore the potential influence of blood type on cardiovascular health.
The implications of blood type extend beyond heart health. Studies have shown that type A blood carries a higher risk of early stroke compared to other types, while type O blood appears to provide some protection. Furthermore, preliminary research suggests that blood type may even affect susceptibility to infectious diseases, including COVID-19. For example, a Danish study found that individuals with type O blood were less likely to contract the virus. Similarly, type O blood has been associated with a lower risk of severe malaria and cholera. While the relationship between blood type and disease outcomes is complex and still under investigation, these insights highlight the importance of knowing your blood type—not just for emergencies, but for a deeper understanding of your health profile.
