Understanding Blood Types: A Key to our Health and Evolution

Understanding Blood Types: A Key to Our Health and Evolution

Less than 100 years ago, the discovery of different blood types revolutionised medicine. Before this, people often died after blood transfusions due to incompatible blood types. When the wrong blood type was given, the recipient’s immune system would react, leading to serious complications like blood clotting. This reaction could be fatal, as clots within the cardiovascular system cause life threatening problems.

The research that identified different blood types was a groundbreaking achievement, leading to safer blood transfusions. The advancement improved patient survival rates by ensuring that only compatible blood was transfused. 

Karl Landsteiner, the scientist behind this discovery, was awarded the Nobel Prize for his work. Before his research, people even experimented with animal blood transfusions, often with disastrous results.

Blood Types and Diet: A Controversial Theory

In the 1990’s, Peter D’Adamo published the popular book, Eat Right 4 Your Blood Type. D’Adamo suggested that different blood types evolved during specific phases of human history and that our diet should align with our blood type for optimal health. According to him:

• Type O evolved during the hunter-gatherer period, so people with Type O blood should follow a meat heavy diet.
• Type B developed in the Himalayan highlands 10,000-15,000 years ago.
• Type A emerged during the agricultural phase of human evolution.
• Type AB is the most modern blood type, combining traits of both A and B.

Although this theory is controversial, the book has sold nearly 10 million copies worldwide since its release in 1996 and has been translated into a number of languages.

Blood Types Across the World

Blood types offer fascinating insights into human evolution and genetics. For example:

• Type O, the most common blood type, lacks both A and B components. It is especially prevalent in Central and South America, among Australian Aboriginals and in Western Europe, particularly in regions of Celtic ancestry.
• Type A is more common among Caucasian, with 40% of this group having A-type blood, compared to 27% of Asains. It is also frequently found in populations with Viking and Scandinavian ancestry, including parts of Europe, Turkey, Greenland, Australia, New Zealand and northern Canada.
• Type B is common in populations from northern India to the Arctic regions of Russia. 

The Impact of History on Blood and DNA

Blood types and genetics provide a window into human history. For instance, studies show that the bubonic plague had a profound impact on human DNA. In areas heavily affected by the plague, survivors’ genetics changed, making them more susceptible to conditions like arthritis. Meanwhile, populations in regions less affected by the plague showed lower incidences of such conditions.

In conclusion, blood types are not just important for medical purposes, they also tell a story of human evolution, migration and survival.