"O (o) type is easy to be bitten by mosquitoes" Is it true? Is there a difference in blood type?

In the streets, it seems that there is a theory that "blood type O type is easy to be bitten by mosquitoes" from before.

Is this a scientific fact, or is it a kind of gassenet?

This time I would like to introduce the truth of this theory that blood type O type is prone to be bitten by mosquito together with the knowledge of "blood type disease" studying the relationship between blood type and diseases .

▶ Three approaches to blood type
According to Nagahama Bio University professor Hiroshi Nagata medical doctor, there are three approaches to blood type.

One is medical "hematology". It is pure natural science.

Next, "blood type personality diagnosis".

As you know, it is scientifically proven that there is no scientific evidence at the Personality Psychology Association.

In other words, it can be said that it is like fortunetelling. And finally, although it is not an official technical term, the relationship between blood type and illness is considered epidemiologically (epidemiology is a field of medicine to investigate trends and causes of diseases for human groups) I will demonstrate "blood type disease".

However, there are not many spectacular findings as there are so many research fields.

According to Dr. Nagata, the scientific journal "Nature" is the result of blood type disease research until the 20th century, "Since the blood type is a plain genetic indicator, enormous research to relate this to the constitution and disease was done But what I understood was that it was only a little non - O - type compared to O - type, it was prone to gastric cancer, and O - type was more likely to be slightly susceptible to stomach ulcers "(Nagata Translation) It is.

▶ The grounds for "O type is easy to be bitten by mosquitoes"?
By the way, what kind of thinking of blood type disease is "O type is easy to be bitten by mosquitoes" of the main theme?

Dr. Nagata probably said that this theory was probably because such a paper was published in "Nature" in the 1970s.

The experiment concluded that it was easy to be stabbed in the order of O type, B type, AB type, and A type, when we conducted experiments to inhale the blood of the subjects to "Hamadara mosquito" living in Gambia in West Africa.

However, as this was not so much confirmed, it seems that it was concluded that the malaria (mediating mosquito) and the blood type apparently had nothing to do with it in the 1990's.

So now, when you browse the site on which the doctor was written, there are many conclusions that "There will be no scientific relationship."

▶ O type is strong against malaria! What?
In 1998, when American researchers examined 489 malaria patients in Zimbabwe in the southern part of Africa, it is easy for malaria to worsen in type A, type B is more likely to become severe, type O is rather resistant I got a result that it is strong.

Inspired by this research, similar conclusions have been raised several times.

In other words, although there is no difference in the establishment of disease, it is an opinion that the resistance power after being affected varies depending on the blood type.

Looking at this "blood type distribution by country, region, and ethnic group", as for malaria contamination zone, in other places such as equator Africa, Amazon River Basin, India to Southeast Asia, Papua New Guinea, The proportion of O type is larger than that of O type.

As a reason for that, it is hypothesized that malaria might have culled non-O type.

By the way, in Japan, it is 38:% A, O: 30%, B: 22%, AB: 10%, 4: 3: 2: 1.

This is not a common ratio in the world.

Moreover, it seems that there is a trend of "West A East B" and "North A South O" on a global scale.

▶ O type is vulnerable to cholera! What?
The type O which is strong against malaria is blood type unnecessary for infectious disease, he says that blood type disease science "is not so".

For example, in South Asia and Southeast Asia, the proportion of Type B is larger than O type.

In India, O type is 37%, B type is 33%, Vietnam is like O type: 42%, B type: 30%, etc.

Also in the Amazon River basin, O type: 100% is also there.

Regardless of why the proportion of type B, which is likely to become severe, is high in India (South Asia) and Vietnam (Southeast Asia) in the same malaria contaminated area, the O type is strong against malaria but weak against cholera, and in these areas, it is culled as cholera Hypothesis has been made that the ratio of O type is decreasing.

▶ Relationship between blood type and illness
In addition, as a blood type disease research, for example, O type tends to be a pancreatic cancer, it is prone to digestive ulcer, H. pylori likes O type, A type is prone to thrombosis etc., Interesting views are being raised.

Nonetheless, these are the conclusions that were discovered primarily by epidemiological research.

So, for example, we have set ourselves the future challenge of "to clarify the relationship between blood type and disease more precisely from the standpoint of genetics, immunology, etc." and to prepare immature natural science It seems to be self-prescribed as it is.