Researchers found that people with blood type AB had a 4 percent higher risk of Deep Vein Thrombosis than people with type O. Scientists at the University of Vermont studied over 30,000 people and found that people with blood type AB are 82 percent more likely to develop thinking and memory issues that can lead to dementia than people with other blood types. They are roughly 26 percent more likely to contract stomach cancer than people with type B or O and also have a 23 percent increased risk for heart disease.
Women with blood type O are twice as likely to have a lower egg count and poorer egg quality than others. Women with blood type A were better protected against diminishing egg counts over time. The researchers measured the level of reproductive hormone FSH in the women and adjusted for other fertility factors, such as age and BMI. Women with blood type O were more likely to have higher levels of FSH, indicating a low ovarian reserve. On a positive side, people with blood type O are less at risk for heart disease than those with different blood types. A study found that people with blood type O are 37 percent less likely to develop pancreatic cancer than those with different blood types. They may also produce less cortisol than type A, but they are prone to overproducing adrenaline during times of stress, creating a “fight or flight” reaction. This makes it more difficult for type O’s to clear the cortisol from their system. Because of their high levels of adrenaline, people with type O benefit more from high-intensity exercise such as running or kick-boxing.
People with type A are 20 percent more likely than people with type B or O to contract stomach cancer. A study followed over a million people for a 35 year period and found that people with type A or AB are also more vulnerable to the risks of other factors such as smoking and alcohol use. Type A have 5 percent increased risk for heart disease.
People with blood type B have 11 percent increased risk for heart disease.