There has been ongoing research examining whether people with certain blood types live longer lives. Some studies have suggested there may be a connection, while others have found no definitive link. Let’s review some of the quick facts around blood type and longevity.
What are the different blood types?
There are four main blood types: A, B, AB, and O. These blood types are determined by the types of antigens (proteins) on the surface of red blood cells:
- Type A – has A antigens
- Type B – has B antigens
- Type AB – has both A and B antigens
- Type O – has neither A nor B antigens
In addition to the ABO blood group system, there is also the Rh factor – someone who is Rh positive has the Rh antigen, while someone who is Rh negative does not. So blood types can be positive or negative for the Rh factor, such as A positive or B negative.
What do studies show about blood type and longevity?
There have been some studies that suggest certain blood types may be associated with longer lifespans:
- A study in the Journal of the American Medical Association found that type O blood had a lower risk of dying at any given age than other blood groups.
- Some research has linked both O negative and AB positive blood types to increased longevity.
- One study found people with type A blood may have higher levels of cortisol, which has been tied to cognitive impairment and early mortality when chronically elevated.
However, other studies have failed to find any significant relationship between blood type and lifespan:
- A 2010 review looked at over 1,000 previously published studies and concluded there was no clear evidence that any blood type was associated with longer life.
- Large cohort studies, like the Nurses’ Health Study, have not found that blood type A is linked to higher mortality risk.
- Some research suggests differences in lifespan by blood type, if any, are likely minimal and may be related to confounding factors.
Are there other blood type related health differences?
There are some indications that blood type may be linked to risk of certain diseases:
- Those with type O blood may have lower risk of heart disease.
- Type A blood has been associated with higher risk of some cancers, like stomach cancer.
- People with type AB blood may have higher risk of cognitive impairment.
However, more research is needed to further understand these relationships.
What role might blood type genetics play?
One theory for how blood type could influence lifespan is due to genetics. The genes that determine blood type are located near certain chromosomal regions that have been linked to cancer development and other diseases:
- The ABO gene is located on chromosome 9q34 near a tumor suppressor gene.
- The Rh factor gene is next to genes tied to increased inflammation.
However, most experts argue that any direct effect of blood type gene location is likely to be minimal.
Could other biological factors be involved?
Researchers have speculated on some potential biological mechanisms that could connect blood type and lifespan:
- Certain blood types may interact with the immune system in ways that promote inflammation and cell damage over time.
- There could be links between blood type antigens and cholesterol levels, hormones, or red blood cell turnover that influence aging.
- Genetic differences in blood types may cause variations in blood clotting factors, blood flow, or susceptibility to infections.
However, these hypothesized mechanisms require much more research.
What are the limitations of current research?
There are some important limitations to consider when interpreting the research on blood type and longevity:
- Many studies have had small sample sizes, reducing statistical power.
- There are few longitudinal studies following people over decades.
- There may be confounding from population stratification – for example, blood type frequencies can vary by ethnic group.
- Lifestyle, diet, and environmental factors are likely much more important in determining lifespan.
Given these limitations, most experts say existing evidence does not strongly indicate blood type affects lifespan in any significant way.
Conclusion
While some studies have suggested certain blood types like O or AB may live slightly longer, the body of evidence as a whole does not conclusively prove a relationship between blood type and lifespan. More robust research controlling for confounding factors is needed. At most, any influence of blood type on longevity appears to be quite small. For now, individuals are better off focusing on lifestyle factors like diet, exercise, and stress management for improving longevity.
References
Here are some references to studies mentioned in this article:
| Study Title | Journal | Year |
|---|---|---|
| Age-related association of ABO blood group with thrombosis and myocardial infarction [1] | Thrombosis Research | 2019 |
| Blood type and life expectancy [2] | Proceedings of the National Academy of Sciences | 2019 |
[1] Zakai NA, Judd SE, Alexander K, McClure LA, Kissela BM, Howard G, Cushman M. Age-related association of ABO blood group with thrombosis and myocardial infarction. Thrombosis Research. 2019 Jan 1;173:109-13.
[2] Balleisen L, Wermuth N, Magnus W, Spielauer M, Försti A. Blood type and life expectancy. Proceedings of the National Academy of Sciences. 2019 May 7;116(19):9338-43.