The Blood Type That Could Increase Your Risk Of A Painful Death

Do you know your blood type? Don’t worry if you don’t. Blood type matters if you know you’re going to have surgery or you’re donating blood or organs. Everyone’s blood transports nutrients and oxygen throughout your body, but blood types differ by substances called antigens. These antigens are on your red blood cells and work with your immune system to classify what does or doesn’t belong in your body.

Because your blood type is connected to your immune system, researchers are curious about how your blood type may affect your health. People with the O blood type are less likely to develop blood clots, but they also have a higher risk of bleeding. A 2018 study in Critical Care examined whether this may affect someone’s risk of surviving a severe traumatic injury. Among 901 trauma patients from two emergency rooms, the people with blood type O had a higher death rate. Even after considering age and the severity of the injury, people with blood type O had a three times higher risk of death compared to those with other blood types.

Having type O blood doesn’t mean you’re more accident-prone or more likely to take risks that may wind you up in the ER. However, the study noted that severe bleeding is a major cause of death in trauma patients. Severe bleeding can also worsen brain injuries.

Even though this study only involved about 900 people, other studies have found that people with blood type O are genetically predisposed to bleeding. A 2013 meta-analysis in Seminars in Thrombosis & Hemostasis combined the results of more than 22 studies to find that individuals with blood type O have a 33% higher risk of experiencing bleeding complications.

Your blood needs to clot to prevent excessive bleeding, but too much blood clotting can be bad for your cardiovascular health. According to a 2020 study in Arteriosclerosis, Thrombosis, and Vascular Biology, people with blood types A and B have a 56% higher risk of blood clot-related conditions such as high cholesterol, heart attack, and thrombosis compared to those with blood type O. However, having blood type O was associated with a slightly higher risk of hypertension.

Blood type O+ is the most common blood type in the United States, found in about 37% of the population, according to the Red Cross. Blood type A+ is the second most common. A 2021 review in BioMed Research International noted that blood type may play a role in the risk of various health conditions, though researchers are still working to understand why.

The presence or absence of certain antigens on blood cells can make a person more vulnerable to some infectious diseases while providing protection against others. For example, people with blood type O may be more susceptible to cholera and gastrointestinal infections caused by E. coli, while those with blood type A may have a greater risk of smallpox. Blood type B has been linked to increased vulnerability to strep and tuberculosis. Norovirus infections tend to be more severe in people with blood type O, whereas those with blood type B may have some level of protection.

Blood type may also influence the risk of certain types of dementia. People with blood type AB, which is relatively rare, tend to have higher levels of clotting proteins that can contribute to blood vessel-related conditions. Since metabolic conditions like high blood pressure, heart disease, diabetes, and obesity are also linked to cognitive decline, researchers believe blood type may be a contributing factor. Studies suggest that cognitive impairment is nearly twice as likely to occur in people with blood type AB compared to other blood types.