Do you know your blood type?
Unless you’ve donated blood, were given a transfusion or found out during pregnancy, maybe you’ve never thought twice about it. But coursing through your veins every second of every day are tiny variations that categorize your blood into one of these groups: A+, A-, B+, B-, O-, O+, AB+ and AB-.
Ongoing research into blood type suggests it may matter more than we give it credit for — at least when assessing risk for certain health conditions, especially heart disease. These invisible differences in the blood may give some people an edge at staving off cardiovascular problems, and may leave others more susceptible.
What does blood type mean, and how are they different?
The letters A, B and O represent various forms of the ABO gene, which program our blood cells differently to form the different blood groups. If you have type AB blood, for example, your body is programmed to produce A and B antigens on red blood cells. A person with type O blood doesn’t produce any antigens.
Blood is said to be “positive” or “negative” based on whether there are proteins on the red blood cells. If your blood has proteins, you’re Rh positive.
People with type O- blood are considered “universal donors” because their blood doesn’t have any antigens or proteins, meaning anybody’s body will be able to accept it in an emergency.
But why are there different blood types? Researchers don’t fully know, but factors such as where someone’s ancestors are from and past infections which spurred protective mutations in the blood may have contributed to the diversity, according to Dr. Douglas Guggenheim, a hematologist with Penn Medicine. People with type O blood may get sicker with cholera, for example, while people with type A or B blood may be more likely to experience blood clotting issues. While our blood can’t keep up with the different biological or viral threats going around in real time, it may reflect what’s happened in the past.
“In short, it’s almost like the body has evolved around its environment in order to protect it as best as possible,” Guggenheim says.
The blood types most at-risk for heart…
Read More: Why Blood Type Matters for Heart Health, According to Science