Your Blood Type May Predict Your Risk of Having a Stroke Before Age 60

Blood Type Testing Concept

According to a new meta-analysis, your blood type may be linked to your risk of having an early stroke.

Research could lead to potential new ways to predict and prevent strokes in young adults.

A person’s blood type may be linked to their risk of having an early stroke, according to a new meta-analysis of research. The meta-analysis included all available data from genetic studies focusing on ischemic strokes, which are caused by a blockage of blood flow to the brain, occurring in younger adults under age 60. The study was led by University of Maryland School of Medicine (UMSOM) researchers, and the findings were published on August 31, 2022, in the journal Neurology

“The number of people with early strokes is rising. These people are more likely to die from the life-threatening event, and survivors potentially face decades with disability.  Despite this, there is little research on the causes of early strokes,” said study co-principal investigator Steven J. Kittner, MD, MPH. He is a Professor of Neurology at UMSOM and a neurologist with the University of Maryland Medical Center.

Blood type A had a 16 percent higher risk of having an early stroke and blood type O had a 12 percent lower risk of having a stroke than people with other blood types.

Kittner and his colleagues conducted the study by performing a meta-analysis of 48 studies on genetics and ischemic stroke that included 17,000 stroke patients and nearly 600,000 healthy controls who never had experienced a stroke. They then scrutinized all collected chromosomes to identify genetic variants associated with a stroke. They discovered a link between early-onset stroke – occurring before age 60 – and the area of the chromosome that includes the gene that determines whether a blood type is A, AB, B, or O.

According to the study, people with early stroke were more likely to have blood type A and less likely to have blood type O (the most common blood type) — compared to people with late stroke and people who never had a stroke. Both early and late stroke patients were also more likely to have blood type B compared to controls. After adjusting for sex and other factors, investigators found that people who had blood type A had a 16 percent higher risk of having an early stroke than people with other blood types. People who had blood type O had a 12 percent lower risk of having a stroke than those with other blood types.

“Our meta-analysis looked at people’s genetic profiles and found associations between blood type and risk of early-onset stroke. The association of blood type with later-onset stroke was much weaker than what we found with early stroke,” said study co-principal investigator Braxton D. Mitchell, PhD, MPH, Professor of Medicine at UMSOM.

The scientists emphasized that the increased risk was very modest. They said that those with type A blood should not worry about having an early-onset stroke or engage in extra screening or medical testing based on this finding.

“We still don’t know why blood type A would confer a higher risk, but it likely has something to do with blood-clotting factors like platelets and cells that line the blood vessels as well as other circulating proteins, all of which play a role in the development of blood clots,” said Dr. Kittner. Previous studies suggest that those with an A blood type have a slightly higher risk of developing blood clots in the legs known as deep vein thrombosis. “We clearly need more follow-up studies to clarify the mechanisms of increased stroke risk,” he added.

In addition to Dr. Kittner and Dr. Mitchell, UMSOM faculty involved in this study included Huichun Xu,  MD, PhD, Associate Professor of Medicine; Patrick F. McArdle, PhD, Associate Professor of Medicine; Timothy O’Connor, PhD, Associate Professor of Medicine; James A. Perry, PhD, Assistant Professor of Medicine; Kathleen A. Ryan, MPH, MS, Statistician; John W. Cole, MD, Professor of Neurology; Marc C. Hochberg, MD, MPH, Professor of Medicine; O. Colin Stine, PhD, Professor of Epidemiology and Public Health; and Charles C. Hong, MD, PhD, Melvin Sharoky MD Professor of Medicine.

A limitation of the study was the relative lack of diversity among participants. The data was derived from the Early Onset Stroke Consortium, a collaboration of 48 different studies across North America, Europe, Japan, Pakistan, and Australia. About 35 percent of the participants were of non-European ancestry.

“This study raises an important question that requires a deeper investigation into how our genetically predetermined blood type may play a role in early stroke risk,” said Mark T. Gladwin, MD, Executive Vice President for Medical Affairs, UM Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor and Dean, University of Maryland School of Medicine. “It points to the urgent need to find new ways to prevent these potentially devastating events in younger adults.”

Reference: “Contribution of Common Genetic Variants to Risk of Early Onset Ischemic Stroke” by Thomas Jaworek, Huichun Xu, Brady J Gaynor, John W. Cole, Kristiina Rannikmae, Tara M Stanne, Liisa Tomppo, Vida Abedi, Philippe Amouyel, Nicole D Armstrong, John Attia, Steven Bell, Oscar R Benavente, Giorgio B Boncoraglio, Adam Butterworth, for the Cervical Artery Dissections and Ischemic Stroke Patients (CADSIP) Consortium, Jara Carcel-Marquez, Zhengming Chen, Michael Chong, Carlos Cruchaga, Mary Cushman, John Danesh, Stephanie Debette, David J Duggan, Jon Peter Durda, Gunnar Engstrom, Chris Enzinger, Jessica D Faul, Natalie S Fecteau, Israel Fernandez-Cadenas, Christian Gieger, Anne-Katrin Giese, Raji P Grewal, Ulrike Grittner, Aki S Havulinna, Laura Heitsch, Marc C Hochberg, Elizabeth Holliday, Jie Hu, Andreea Ilinca, for the INVENT Consortium, Marguerite R Irvin, Rebecca D Jackson, Mina A. Jacob, Raquel Rabionet Janssen, Jordi Jimenez-Conde, Julie A Johnson, Yoichiro Kamatani, Sharon L Kardia, Masaru Koido, Michiaki Kubo, Leslie Lange, Jin-Moo Lee, Robin Lemmens, Christopher R Levi, Jiang Li, Liming Li, Kuang Lin, Haley Lopez, Sothear Luke, Jane Maguire, Patrick F McArdle, Caitrin W. McDonough, James F Meschia, Tiina Metso, Martina Muller-Nurasyid, Timothy D O’Connor, Martin O’Donnell, Leema R Peddareddygari, Joanna Pera, James A Perry, Annette Peters, Jukka Putaala, Debashree Ray, Kathryn Rexrode, Marta Ribases, Jonathan Rosand, Peter M Rothwell, Tatjana Rundek, Kathleen A Ryan, Ralph L. Sacco, Veikko Salomaa, Cristina Sanchez-Mora, Reinhold Schmidt, Pankaj Sharma, Agnieszka Slowik, Jennifer A Smith, Nicholas L Smith, Sylvia Wassertheil-Smoller, Martin Soederholm, O. C Stine, Daniel Strbian, Cathie L Sudlow, Turgut Tatlisumak, Chikashi Terao, Vincent Thijs, Nuria P Torres-Aguila, David-Alexandre Tregouet, Anil M. Tuladhar, Jan H Veldink, Robin G Walters, David R Weir, Daniel Woo, Bradford B Worrall, Charles C Hong, Owen Ross, Ramin Zand, Frank-Erik de Leeuw, Arne G Lindgren, Guillaume Pare, Christopher D. Anderson, Hugh S Markus, Christina Jern, Rainer Malik, Martin Dichgans, Braxton D Mitchell, Steven J Kittner, the Early Onset Stroke Genetics Consortium of the International Stroke Genetics Consortium (ISGC), 31 August 2022, Neurology.
DOI: 10.1212/WNL.0000000000201006

The study was supported by the National Institutes of Health and the Department of Veterans Affairs. Researchers from more than 50 institutions worldwide were co-authors on this study.

37 Comments on "Your Blood Type May Predict Your Risk of Having a Stroke Before Age 60"

  1. Thanks for yr sharing.

  2. I have had a stroke. I have 0+ blood and I am doing just fine. And I am over 30.

  3. Chinedum Julius Nkwocha | September 2, 2022 at 3:51 am | Reply

    Please could one suffering from Prostrate lead to partial stroke? What does constant night dehydration result and what’s the remedy to it?

  4. A blood group has 20 per cent more cortisol, the stress hormone, and a higher percentage of highly sensitive folk have this blood type!


  5. Michele Lisa Johnson | September 2, 2022 at 9:40 am | Reply

    The definition of a vaccine being changed for a death shot is what is going to cause a stroke!

  6. Which one is more likely-A+ or A-? Or does it not matter? I hate it when they make blanket statements about type A without considering difference within a blood type.

  7. I believe there is a lot more than blood type to consider here and that as genetics prove different risks, this study will likely be irrelevant. For example I have Type O+ blood so if I were to base my risk for a stroke on this study alone, I would fall into the lower risk category. However, I have a rare genetic connective tissue disease and an extremely rare gene (my variant is .002% if the world) that causes aortic dissection and aneurysm. My disease and this gene put me at high risk for a stroke especially since I have already had a carotid dissection and aneurysms. As I said, there is much more to our medical profile as a whole in our genetics than our blood type alone. This is not really a fair or full picture of stroke risk in my opinion.

  8. Blood O type is the most modern blood type. A blood type is the most ancient follow by B then AB. Just like Covid likes to attack a type more.

  9. I would infer from this that people with AB are living on borrow time.

  10. Whst about ob negative blood type o thought that was the richmost rarest type

  11. I had a stroke at 38 I have O+blood I was paralyzed left side for 18 mos and only left with left side hearing problems and slightly weakened left side. I am 60 now

  12. Just as long as they’re absolutely positive the vax has nothing to do with it!

  13. I can’t help but think this is more of a numbers game than a blood type thing. The percentage of the population with each blood type is the percentage if the population experiencing various health issues. The article did nothing to explain the correlation between blood type and risk for stroke. It reinforced that a percentage if the population has ea h blood type.

  14. Scarlett destiny | September 5, 2022 at 5:50 am | Reply

    I have no chance! As a B group, I am prone to a stroke either early or late in years, good grief 😔

  15. Scarlett destiny | September 5, 2022 at 5:53 am | Reply

    As a B group, I am prone to be considered either early or late stroker, good grief 😔

  16. Regarding the blood type A with higher chance of DVT. I am A- and am on PREDAXA to keep me from clotting. My trigger is very easy to locate. I desire to share my trigger activity.

  17. I have AB- blood where does that leave me?

  18. Whatever blood type or genetic features you co e from, I haven’t met any who has had strokes if one exercises 2 hours a day, know what to eat what to avoid and a rested mind. You’d more likely get a stroke by following researchers who make millions of dollars what our ancestors have freely ascertained…exercise , eat well and don’t worry…be happy.

  19. I have AB negative blood type so were do i stand in all this

  20. Strokes and blood clots are rising… anybody notice this is happening after the “vaccines”? The CDC won’t admit it, but those shots are causing so much damage!

  21. Anastasia Barela | September 5, 2022 at 8:50 pm | Reply

    What percent does rh negative o negative null have when it comes to stokes or even the vaccine. If there are no antigens in my blood.

  22. From working in the hospital I can tell you that I believe your risk is much greater after you receive the covid vaccine based on what I’ve seen. People are certainly coming in when they’re 40s and 50s with stroke like symptoms. Something I’ve never seen before in 30 years of working at a hospital

  23. I wonder if they’d consider doing a study to see if the increase in strokes and sudden death among seemingly healthy young people under the age of 60 has anything to do with whether a person has had THE jibbity jab and if that percent is dose dependent. BUT WHO would fund THAT study??? 🤔

  24. So what about all the rest of the blood types like all they talk about in this is a and o.

  25. Studies seek to prove something,and are some what biased. The focus,on supportive data may limit the impartiality needed.In other words, what other factors were studied,and if not, why not. Example, so called no lead fuels. The removal of tetra Ethel lead was touted as less harmful.Lots of studies. Today’s no lead fuels, now utilize magnesium, another metal.So, where’s the information on how magnesium affects the neurological health.

  26. What about AB- blood?

  27. I am B+. I am going to ask my doctor to take out all my blood and change it out with type 0. I may have a chance yet…

  28. I would be far more concerned about the gray mass between our ears determining worlds more good or bad…

  29. Had stroke right after second covid shot…..

  30. baby aspirin, drink water

  31. Getting that clot shot will be the biggest risk for people.

  32. Does chronic masturbation play a part? I have to imagine avid harmonica play can influence it as well. I am also 1/16 Neanderthal, so there is no way to tell how long I may live, but I am studying ship building, and I have direct lineage to Bruce and Evan Almighty. I may also be somewhere on the spectrum, but was raised not to recognize color.

  33. We’ve been bamboozled | September 10, 2022 at 4:24 pm | Reply

    According to a new analysis… So is this following the fact that millions of people have taken an experimental drug (some have had several rounds of said drug), and they are finding an influx of strange clots. Weird.

  34. Im R H Negative were does that leave me?

  35. Sherman Merriman | September 11, 2022 at 8:39 am | Reply

    I am a 79 year old, (retired @ 62), A+, RH+, active, male engineer who has had 3 strokes. After much anguish, physicians determined my strokes were caused by sensitivity to foods containing nitrates and nitrites which also cause temporary visual spots and optical vascular migraines. No tumors, cancer or blood clots found. Strokes were minor & occurred at ages: 35, 50 & 60. Doing good as long as I watch my diet.

  36. This study failed to mention mutations in the various clotting factor genes such as Factor V Leiden and others which can cause DVT, PE, and strokes and modify risk factors as well. Among healthy people who are having strokes what besides blood group modifies this risk.

    Also malabsorption states such as the one I have in which I don’t absorb vitamin K can cause issues with bleeding.

    My husband has a mutation with factor V Leiden and threw a blood clot with severe covid 19. He is blood group A as am I. He was hospitalized while I was barely symptomatic yet I have never thrown a clot despite being bedridden.
    Their is far more to this than blood group.

    Needless to say, this is a poorly done study.

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