Memorising your blood type is critical for all sorts of reasons, from knowing who you can accept blood transfusions from to who you can donate your blood to. Not to mention the role it plays in your likelihood of contracting COVID-19. And now, as doctors and scientists do increasingly more research on how a person’s blood type can affect their health, there’s even more of an incentive to pay attention to whether you’re A, B, AB, or O—and whether you’re positive or negative, too.
For example, recent studies have found that a person’s blood type can mean anything from an increased risk of depression to a higher likelihood of developing diabetes. Curious about what your own blood type means? Keep reading to find out.
1. People with type O blood are less susceptible to malaria.
Although people with type O blood are more susceptible to bites, they can thank their genetics for one thing: protection against malaria. Oddly enough, scientists have found that folks with type O blood seldom die from malaria, seeing as the RIFIN protein—the protein that causes malaria—is less able to bond to type O blood cells and therefore cannot do as much damage.
2. People with type O blood are the least likely to suffer from cardiovascular issues.
If you have type O blood, then your heart is in luck: According to research presented at the 2017 World Congress on Acute Heart Failure, individuals with this blood type are less likely to suffer a heart attack or stroke. The bad news? Individuals who are type A, type B, or type AB—in other words, some 63% of the overall population—have a 9% increased risk of both coronary and cardiovascular events.
3. People with type A blood are more likely to develop stomach cancer.
Stomach cancer and type A blood seem to go hand in hand. That’s according to a 2015 study published in the journal Cancer Epidemiology, which found that people with type A blood were 38 percent more likely to develop stomach cancer than those with type O blood.
4. And all non-O blood types are at an elevated risk of pancreatic cancer.
Though non-A blood types are relatively less likely to get stomach cancer, they still have to worry about pancreatic cancer. In the same 2015 study, researchers found that all non-O blood types were at a higher risk of pancreatic cancer, and subjects with type B blood were 59 percent more likely to come down with the cancer.
5. People with type AB blood are much more likely to develop cognitive issues.
If your blood type is AB, then you’ll want to keep a close watch on your cognitive health. One 2014 study published in the journal Neurology analysed the relationship between blood type and brain health and found that people with type AB blood had an 82 percent higher risk of cognitive impairment.
6. People with negative blood types tend to have more mental health issues.
The minority of the population who is Rh negative is at a higher risk of certain mental health issues. A 2015 study of more than 3,000 subjects published in the journal PLoS One found that “Rh negative men more often reported certain mental health disorders including panic disorders, antisocial personality disorders, and attention deficits.”
7. And they also have more skin allergies.
In addition to mental health issues, people with Rh-negative blood types are also more prone to developing allergies. In the same PLoS One study, researchers found that subjects with Rh-negative blood were slightly more likely to have skin allergies.
8. Your blood’s Rh factor can cause complications during pregnancy.
Whether or not you’re Rh positive or Rh negative could have an impact on your pregnancy. According to the American College of Obstetricians and Gynaecologists, problems can occur when a woman is Rh negative and her foetus is Rh positive, as this can result in something called Rh incompatibility. “If the blood of an Rh-positive foetus gets into the bloodstream of an Rh-negative woman, her body will understand it is not her blood and will fight it by making anti-Rh antibodies,”. “These antibodies can cross the placenta and try to destroy the foetus’s blood. This reaction can lead to serious health problems and even death in a foetus or newborn.”
9. The majority of the Latino-American population is type O+.
While type O is the most common blood type overall, it’s especially prevalent in the Latino-American community. According to the American Red Cross, approximately 53% of Latino-Americans are type O+ and 4% are type O-.
10. Negative blood types are less common.
That statistic about the Latino-American community makes sense, seeing as negative blood types—whether type A, type B, type AB, or type O—are few and far between. In fact, according to the Oklahoma Blood Institute, only about 18% of the total U.S. population has a negative blood type.
11. Blood types were first discovered in the early 1900s.
Wondering who pioneered this science in the first place? In 1909, Austrian scientist Karl Landsteiner became the first person to properly identify the four main blood groups. It’s thanks to his research that we now know which blood types to use (and which not to use) with patients in need of transfusions. In 1930, he was rewarded for his contributions when he was given the Nobel Prize for Physiology or Medicine.
12. Women with type O blood are more likely to deal with fertility issues.
One of the many things that can contribute to a woman’s fertility is her blood type. At the Yale University Fertility Center in 2011, researchers analysed subjects’ levels of follicle-stimulating hormone (FSH) and found that women with type O blood were more likely to have higher FSH levels. The problem is that high levels of FSH are typically an indication of a diminished ovarian reserve, which means that a woman with type O blood might be less likely to get pregnant as she gets older.
13. Your blood type boils down to sugar.
Have you ever wondered what makes your blood type A, B, AB, or O? Turns out, it’s all about the sugar. The blood types are named after antigens that are found on the surface of your red blood cells. These antigens are simple chains of sugars, according to Stanford School of Medicine. “The A flavour makes the A sugar, and the B one makes the B sugar. It turns out that the O flavour doesn’t make any sugar,” according to Stanford. “Someone that’s ‘AO’ will be type A, because the O flavour of the gene makes no sugar. This person only has the A sugar.” But what about the positive or negative element? Well, that’s all about the Rhesus factor (or Rh factor). If you don’t have the Rh factor, your blood is negative. If you do have it, your blood is positive.
14. There is one blood type that’s the “universal donor.”
Type O- blood is in extremely high demand at hospitals—not just because it’s one of the rarest blood types, but also because it’s the “universal donor.” Because O- is Rh-negative, it can be given to people with both positive blood types and negative blood types. These folks can also donate to A, B, and AB blood types. Though a foreign antigen could cause the body to attack, there are no antigens present in type O blood, so there’s nothing to attack.
15. And there’s another blood type that’s the “universal recipient.”
If your blood type is AB+, then you’re in luck. This blood type is known as the “universal recipient,” seeing as people who have it running through their veins can receive blood from any type A, type B, type O, or type AB donor. Because type AB blood contains both A and B antigens, as well as the Rh factor, it can tolerate a transfusion from anyone on the ABO spectrum.
16. People with type B blood are more susceptible to gastroenteric cancers.
Though doctors and scientists aren’t entirely sure what causes cancer, one thing that they do know is that people with type B blood are more likely to develop certain cancers. In fact, one 2012 study published in the World Journal of Gastroenterology found that type B blood individuals were about 50 percent more likely to be diagnosed with both easophageal and biliary cancers.
17. Non-O blood types suffer from serious clotting issues more often than O types.
Type A, type B, and type AB blood types have been shown to have higher levels of the proteins von Willebrand factor and factor VIII, both of which contribute to clotting. In fact, a 2007 study published in the Journal of Thrombosis and Haemostasis found that people with type A, B, or AB blood were 31 percent more likely to develop venous thromboembolism, a condition in which a blood clot forms in the leg, groin, or arm and lodges itself in the lungs.
18. Non-O blood types are at higher risk of type 2 diabetes.
When French researchers analysed data from some 82,000 women in 2015, they found that those with type A blood were 10 percent more likely to develop type 2 diabetes and those with type B blood were 21 percent more likely to develop the disease. The scientists hypothesise that a person’s blood type may play a role in their gut microbe makeup, which could, in turn, affect metabolism and contribute to diabetes risk.
19. The Japanese believe that blood types can predict personality traits.
According to 2015 research published in the International Journal of Science, Spirituality, Business and Technology, “people [in Japan] strongly believe that the blood type influences one’s personality, weaknesses, and strengths.” Per these beliefs, people with type A blood are calm and collected, artistic, and polite; people with type B blood are practical, goal-oriented, and strong-willed; people with type O blood are outgoing, energetic, and outspoken; and people with type AB blood tend to have characteristics on both sides of the spectrum.
20. One blood type tends to attract mosquitos more than the others.
Many factors contribute to whether or not you are a magnet for mosquitos, including your blood type. In one 2004 study published in the Journal of Medical Entomology, researchers found that one species of mosquito—Aedes albopictus—landed on 83% of subjects with type O blood and just 47% of subjects with type A blood. Scientists believe that mosquitos may be able to sense the sugars some people secrete through their skin based on their blood type.
Remember knowing more about your blood type can be beneficial to your health in the long run.