What is the significance of different blood types

The reasons are unclear. These disease susceptibilities are unlikely to confer a significant survival advantage on a population, however, because unlike malaria they often occur beyond a subject's reproductive years.

On the other hand, there is some evidence that group O members are more susceptible than other blood type individuals to the agent that causes bubonic plague, whereas group A people are more susceptible to smallpox virus. These correlations may account for the increased frequency of the B gene in China, India and parts of Russia, which suffered epidemics of both of these diseases.

Infectious organisms that carry A- and B-like antigens may have indeed played a role in the somewhat different distribution of blood types worldwide. Finally, a number of myths exist about blood types. Claims have been made that people from group A have the worst hangovers, group O the best teeth, and group A2 the highest IQs, for example.

With these and other purported associations, both the scientific basis and evolutionary significance are limited at best. Sign up for our email newsletter. As a scientist, he found Eat Right 4 Your Type lacking.

But El-Sohemy realised that since he knew the blood types of his 1, volunteers, he could see if the Blood Type Diet actually did people any good. El-Sohemy and his colleagues divided up their subjects by their diets.

The scientists gave each person in the study a score for how well they adhered to each blood type diet. The researchers did find, in fact, that some of the diets could do people some good. People who stuck to the type A diet, for example, had lower body mass index scores, smaller waists and lower blood pressure. People on the type O diet had lower triglycerides. The type B diet — rich in dairy products — provided no benefits. Anyone on a type O diet cuts out lots of carbohydrates, with the attending benefits of this being available to virtually everyone.

Monkey business One of the appeals of the Blood Type Diet is its story of the origins of how we got our different blood types. But that story bears little resemblance to the evidence that scientists have gathered about their evolution. It turned out that some primate species had blood that mixed nicely with certain human blood types.

But for a long time it was hard to know what to make of the findings. Type A blood might have evolved more than once. The uncertainty slowly began to dissolve, starting in the s with scientists deciphering the molecular biology of blood types. They found that a single gene, called ABO, is responsible for building the second floor of the blood type house. The A version of the gene differs by a few key mutations from B. People with type O blood have mutations in the ABO gene that prevent them from making the enzyme that builds either the A or B antigen.

Scientists could then begin comparing the ABO gene from humans to other species. Gibbons and humans both have variants for both A and B blood types, and those variants come from a common ancestor that lived 20 million years ago.

But the evidence that scientists have gathered so far already reveals a turbulent history to blood types. In some lineages mutations have shut down one blood type or another. Chimpanzees, our closest living relatives, have only type A and type O blood.

Gorillas, on the other hand, have only B. And even in humans, scientists are finding, mutations have repeatedly arisen that prevent the ABO protein from building a second storey on the blood type house. These mutations have turned blood types from A or B to O. Bombay puzzle Being type A is not a legacy of my proto-farmer ancestors, in other words.

Surely, if my blood type has endured for millions of years, it must be providing me with some obvious biological benefit. Otherwise, why do my blood cells bother building such complicated molecular structures? Yet scientists have struggled to identify what benefit the ABO gene provides. The most striking demonstration of our ignorance about the benefit of blood types came to light in Bombay in If A and B are two-storey buildings, and O is a one-storey ranch house, then these Bombay patients had only an empty lot.

Since its discovery this condition — called the Bombay phenotype — has turned up in other people, although it remains exceedingly rare. Those with the Bombay phenotype can only accept blood from other people with the same condition. Even blood type O, supposedly the universal blood type, can kill them. Some scientists think that the explanation for blood types may lie in their variation. Doctors first began to notice a link between blood types and different diseases in the middle of the 20th Century, and the list has continued to grow.

From Greenwell I learn to my displeasure that blood type A puts me at a higher risk of several types of cancer, such as some forms of pancreatic cancer and leukaemia. According to Northwestern Medicine , studies show that:. According to a recent study from Harvard Medical School researchers published in the journal Annals of Hematology , blood type has no effect on how sick one becomes with coronavirus despite initial claims that it might.

Skip to main content Search for a topic or drug. What does your blood type mean for your health? By Donna Christiano Aug. Top Reads in Health Education. Diabetes and exercise Nov. What is insulin resistance? Do coffee and diabetes mix? Diabetes in women Nov. Looking for a prescription? Search now! Type your drug name. In cases where the father of the baby has the RhD positive blood group and the mother of the baby has the RhD negative blood group, the baby may be RhD positive which can cause compatibility issues.

If the baby has the RhD positive blood group, it may cause medical complications. Blood group reagents are solutions that are used to determine blood groups. The reagents contain antibodies that will detect the presence of the appropriate antigens on the surface of red blood cells. The reagents can cause the agglutination clumping on the test red blood cells which carry the appropriate antigen. No clumping of the test red blood cells indicates the absence of the appropriate antigen.

There are several techniques that can be used to detect blood groups. All techniques are based on the binding of an antibody to the appropriate antigen which is called agglutination. The agglutination can be seen macroscopically as the clumping together of the red cells. After the washing of the red cells, the saline solution is removed from the test tube and a bridging reagent Anti-Human Globulin reagent is added to the red cells in the test tube.

The test tube is spun in a centrifuge. The test result agglutination or no agglutination is read macroscopically.