There are four types of blood: A,B, AB or 0 and also a Rh factor which can be either positive or negative for each blood type. The notorious Nazi doctor Otto Rehe was the reason why the effect of blood types on human health was not studied for a long time. He claimed that Type A is characteristic for Aryans, and the type of their enemy was B. Anyway, recent studies have proven the link between a blood type and certain diseases.
Blood type A
People with this blood type are more fertile but also prone to drinking more alcohol. They have an increased risk of stomach cancer compared to other blood types, especially if they are smokers or if they drink alcohol very often. Women who have this blood type can become pregnant even in older age since they have a larger ovarian reserve. People with blood type A have predisposition to alcoholism and Obsessive Compulsive disorder too.
Blood type B
These people have good metabolism however they are more prone to ulcers. Other health conditions linked to blood type B are memory problems and senility and Alzheimer’s disease in older age. Bacteria caused inflammations are also often. Still, not everything is bad about this blood type. People with blood type B have a very fast metabolism, they respond well to exercise which leads to easier muscle building.
Blood type 0
Blood type 0 has low risk of getting heart disease and stomach cancer but an increased risk when it comes to stomach ulcers caused by Helicobacter pylori. Having this blood type means you have the smallest risk of dying from malaria but you are more vulnerable when it comes to cholera. Men with this type are more prone to obesity and women have fewer and poor quality eggs which means they are less likely to conceive naturally. A good thing about this blood type is that having it means you are resistant to stress, because in people with blood type 0 the stress hormone cortisol to drop quickly after experiencing traumatic events.
Blood type AB
People with this blood type are more at risk of heart attack and developing a heart disease, digestive problems, such as chronic gastritis, Cronh’s disease etc. Particularly women with type AB are at a greater risk of suffering from a condition caused by high blood pressure – pre-eclampsia and occurrence of ovarian cancer.
According to studies, cortisol levels also normalize faster in people with blood type AB and they are less prone to having problems with vision.
Source