Some studies suggest people with blood type O may have a lower risk of cancers compared to other blood groups, possibly due to differences in inflammation and immune response, but overall risk depends on many factors like genetics and lifestyle.

Knowing your blood type could do more than help in emergencies—it may also offer insight into long-term health risks, including cancer. Blood type is determined by the presence or absence of certain antigens on the surface of red blood cells, commonly categorized into A, B, AB, and O, along with the Rh factor (positive or negative). While this classification is most often associated with blood transfusions, researchers have increasingly explored whether these biological differences might influence susceptibility to certain diseases. Over time, patterns have emerged suggesting that blood type could play a subtle but meaningful role in shaping how the body responds to inflammation, infection, and even the development of cancer.

One of the most discussed findings in this area is that individuals with blood type O may have a slightly lower overall risk of developing certain types of cancer compared to those with types A, B, or AB. Some studies have particularly highlighted reduced risks for cancers such as pancreatic and gastric cancer among people with type O blood. Scientists believe this could be linked to how antigens interact with the immune system. In people with non-O blood types, certain antigen structures may create conditions that make it easier for cancer cells to grow or evade immune detection. However, it is important to understand that these differences are statistical and do not determine an individual’s fate.