What your blood type might reveal about your health

You already know that many factors influence your susceptibility to various diseases - from genetics and lifestyle to environmental exposures. However, did you know your blood type could also play an important role in determining your disease risk? 

Your blood type explained

“Your blood type is important because if you need a blood transfusion or an organ transplant (or you are a blood donor or organ donor) the success depends on whether your blood type is compatible with the other person’s,” says Dr Gamuchirai Tadzimirwa, a specialist physician and clinical haematologist at Mediclinic Panorama. “It may also affect your health in other ways. It may influence how your body interacts with various pathogens and disease processes.”

Based on the type of antigen (a type of protein found on red blood cells) your blood will be categorised as type A, type B, type AB, or type O. The Rhesus factor, or Rh factor, is another type of protein found on the outside of red blood cells. If you have the Rh factor, you are Rh positive (+), and if you don’t, you’re categorised as Rh negative (-).

Cardiovascular disease

One of the most well-established connections between blood type and disease risk involves cardiovascular health. Research consistently shows that people with blood types A, B, and AB have a higher risk of heart disease and blood clots compared to those with type O.

“The exact reasons for this are not fully understood,” says Dr Tadzimirwa. “But studies show that blood types A, B and AB may have higher concentrations of a blood clotting protein, which could increase the risk of blood clots and heart attacks.”

Some studies have also linked non-O blood types (particularly type A) to higher cholesterol levels, which can lead to heart disease. Blood types A, B and AB may also have higher levels of certain inflammatory markers that have been linked heart failure.

Infectious diseases

Dr Tadzimirwa adds that your blood type can also influence your susceptibility to certain infections. For instance, people with Type A may face a higher risk for contracting certain bacterial infections and were shown to be more vulnerable to the COVID-19 virus. Type O individuals are said to be more susceptible to infections like cholera, but seem to be protected against severe malaria.

Cancer

The relationship between blood types and cancer risk has been studied for many years. “People with type A blood appear to have a higher risk of stomach cancer, possibly due to an increased susceptibility to Helicobacter pylori infections, which can lead to stomach inflammation and cancer,” says Dr Tadzimirwa. The ABO gene is present in people only with blood type A, B, or AB. This gene has also been connected to other cancers, including lung, breast, colorectal, prostate, liver, and cervical cancer, but researchers have yet to pin down how the ABO gene may put you at risk.

Cognitive health

According to a 2014 study published in Neurology, people with blood type AB may be up to 82% more likely to develop memory loss when they’re older than people with other blood types. Research also reveals that people with Type O blood appear to have larger volumes of grey matter which might protect them from dementia later in life.

Understanding your blood type’s potential health implications doesn’t mean you’re destined to develop specific diseases. Rather think of your blood type as one piece of your health puzzle - informative but incomplete on its own. “Your health journey remains largely within your control through good lifestyle choices, regardless of your blood type,” says Dr Tadzimirwa.