Risk of cardiovascular disease varies with blood type

Most people are aware that high blood pressure, smoking, obesity, diabetes, and high cholesterol are risk factors for developing heart disease, but now we can add one more to this list: blood type. Fortunately, most people fall into the low-risk category in this regard.

Published August 14 in the journal Arteriosclerosis, Thrombosis and Vascular Biology, Dr. Lu Qi and his team at the Harvard School of Public Health analyzed data on over 77,000 individuals aged 30 to 75. The participants were followed for over 20 years to see if there was a correlation between blood type and heart disease.

They found that people with type AB blood had about a 23 percent increased risk for developing heart disease, people with type B had an 11 percent increased risk, and type A individuals had a 5 percent increased risk over the lowest risk group; that is, people with type O blood. The risk did not vary at all based on the Rh positive or negative sub-type.

In Brazil, here is the distribution of blood types (very similar to the percentage distributions in the U.S.):

45% of people have type O blood

42% type A

10% type B

3% type AB blood.


Here is a summary of the increased risk of cardiovascular disease:

Type O blood= no increased risk

Type A blood= 5% increased risk

Type B blood= 11% increased risk

Type AB blood= 23% increased risk

Blood type is an inherited characteristic, determined by both parents, and (unless you get a bone marrow transplant), you cannot change your blood type. What actually determines your type is the presence or absence of various proteins, carbohydrates, and lipids on the surface of your red blood cells.

People with type O blood are considered “universal donors” since they can theoretically donate to anyone, while at the other end of the spectrum, those with type AB blood are considered “universal recipients” since they should be able to receive a transfusion from anyone. Individuals with type O blood can only receive transfusions from other people with type O blood.

The reason that non-type O individuals carry a higher risk seems to be that these people have more clotting factors, and their cholesterol levels may be slightly higher. Also the non-type O group may have increased inflammatory and immune responses that lead to more plaque formation and clotting within the blood vessels—a principal characteristic of cardiovascular disease.

So what can you do if you are not type O? It’s not all that significant in the big picture, because there are so many other factors that you can control (unlike your blood type).  You can counteract any increased risk by being extra careful about your diet and weight, not smoking, getting regular exercise, and if you have diabetes or high blood pressure, making sure they are under optimal control.

Should you need to find a cardiologist or any other medical specialist in Brazil, you can do so through our main website:

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