If this sounds a little odd, it is — your blood type determines not only who you can donate to, but it also influences your personal health. It can reveal the diseases you’re most at risk of, or how severe they are if you get them. Malaria, for example, is less harmful to people with type O blood, according to a report in Sydney-based Daily Telegraph.
Reportedly, there are more than 300 blood types, but they all fall into one of four key groups — type A, B, AB or O. A number of researchers say that these blood types can reveal complex patterns of personal health. Here are seven to consider:
Who is at risk? A, B, or AB
In a 2015 study, investigators found that those with A, B, or AB blood type were at higher risk for developing stomach cancer, compared with people who were type O. There was no significant association between blood type and overall cancer mortality, however. Another study noted that a genetic variation may increase the risk of pancreatic cancer among people with A, B, or AB blood types. Meanwhile, O blood type has been linked with a reduced risk of various cancers, including colorectal, stomach, and pancreatic. The American Cancer Society lists type A blood among the risk factors for stomach cancer.
“It may be more accurate to say people with type O blood are at a lower risk for pancreatic cancer, given the work researchers are doing on bacterial infection,” Dr Sanjay Aggarwal, a general physician at Holistic Healthcare Centre in Delhi, said.
2. Memory problems
Who is at risk? AB
A 2014 study found people with type AB blood were 82% more likely to experience difficulties with memory recall, language, and attention than people with other types. In addition, AB blood type was associated with higher levels of a blood clotting protein compared with O type. Other research found that AB blood type was linked with a higher risk of stroke, which can result from a clot blocking blood flow to the brain.
3. Heart disease
Who is at risk? AB
A 2012 study from Harvard University found people with non-O blood also happen to have an increased risk for cardiovascular disease. But those with type AB blood were the most at-risk overall, demonstrating a 23% greater chance of suffering from heart disease than type O. While type B was associated with an 11% higher risk, and type A, a 5% higher risk. Though it’s not clear what might account for this elevated risk, other research has linked blood type A with higher levels of LDL (“bad”) cholesterol, and type AB with an increase in inflammation, both of which can raise heart disease risk.
Kolkata-based general physician, Dr Shayan Dasgupta feels people’s blood type should be given the same weight we already assign to cholesterol and blood pressure. “While people cannot change their blood type, these findings may help physicians better understand who is at risk for developing heart disease,” he said.
Who is at risk? A
People with type A blood are more likely to have higher levels of cortisol, the stress hormone, in their body, while type O produces the least amount of cortisol, said a report.
“When the adrenal gland dumps more and more cortisol into the blood, people’s stress response grows more acute. Hence, people with type A blood may find themselves getting anxious more quickly,” Dr Dasgupta said.
“Type O’s are more prone to problems that arise from an inability to clear stress hormones from their system quickly,” Dr Dasgupta added. “So, it takes more to get a Type O stressed, but it takes more to de-stress them as well.”
5. Digestive problems
Who is at risk? A and O
Research has estimated that people with type B blood contain up to 50,000 times the number of strains of friendly bacteria than people with either type A or O blood. They have the most resilient digestive systems and aren’t overly sensitive to food choices.
According to a report,on the other end of the spectrum are people with blood group A. Some studies suggest that these people have a low acidic content making it difficult for them to digest meat. Somewhere in the middle is AB’, which combines the vulnerabilities of both A and B groups and falls in the sensitive zone.
People with type O blood are more prone to stomach problems because of the high acidic content in the stomach. So while they can digest protein well, they have to be cautious about consuming too many fats or carbohydrates.
“People process food differently depending on their primary blood type, which is said to have evolved at different points in human history. The idea that eating a diet aligned with your blood type can help you lose weight and reduce your risk for chronic diseases,” Dr Aggarwal said.
Who is at risk? A and B
In a 2015 study, researchers from France looked at health data from more than 82,000 women and found that type 2 diabetes was more likely to develop in those with type A and B blood, compared with type O.
Who is at risk? A
People with type O blood have a degree of protection against the most dangerous form of malaria, which is caused by the mosquito-transmitted parasite, Plasmodium falciparum, as opposed to less-dangerous species of Plasmodium. A report said that to find out what accounts for this protection, Swedish researchers looked at a specific protein secreted by the malaria parasite and found that it tends to bind more tightly to red blood cells that are type A than type O. Their findings were reported in the journal Nature Medicine in 2015.