Your blood type does more than determine the kind of transfusions you can receive. Emerging research suggests it may also offer important clues about long-term brain health and cognitive decline—raising new questions for doctors, scientists, and aging Americans.
AB Blood Type Shows Higher Risk in Early Findings
There are four major blood groups in the United States: A, B, AB, and O, each with positive and negative variations. AB remains the rarest, accounting for less than 4% of the U.S. population. Yet early evidence points to an intriguing pattern: people with AB blood may face a higher risk of developing memory and thinking problems as they age.
One well-known study, published in Neurology, tracked more than 30,000 adults over the age of 45 for an average of 3.4 years. During that time, 495 participants developed cognitive impairment. Researchers discovered that individuals with AB blood type were significantly overrepresented in that group—suggesting an 82% higher risk compared with other blood types.
The study also examined elevated levels of factor VIII, a blood-clotting protein linked to cognitive issues. People with AB blood were more likely to have increased amounts of this protein in their system.
Conflicting Evidence Shows the Debate Isn’t Settled
Not all research agrees. A massive study published in PLOS One followed more than 1.6 million blood donors in Sweden and Denmark. Tracking thousands of dementia cases—including Alzheimer’s—it found no clear connection between ABO blood type and dementia risk.
Experts say this conflicting data highlights one important truth: dementia is complex. Genetics, environmental exposure, cardiovascular health, lifestyle habits, and aging itself all play critical roles.
Stroke and Heart Health May Help Explain the Connection
More recent findings suggest the relationship may be indirect. A 2022 Neurology study reported that:
People with type A blood had a 16% higher risk of stroke
Individuals with type O blood had a 12% lower risk of stroke
Stroke, along with high blood pressure and obesity, is a well-established risk factor for memory loss. Previous research has also linked ABO blood groups with coronary heart disease, stroke, and venous thromboembolism.
That means cognitive decline in people with AB blood may stem from related cardiovascular vulnerabilities—not the blood type alone.
Why This Matters as Dementia Rates Climb
The United States is facing an aging population. Cases of dementia and age-related memory loss continue to rise, placing emotional and financial pressure on families and healthcare systems. Because early treatment is limited, prevention and awareness remain key.
Should People With AB Blood Do Anything Different?
Doctors aren’t recommending panic—or special testing—based on blood type alone. However, experts say individuals with AB blood might consider:
Regular cognitive screenings
Monitoring blood pressure and cholesterol
Maintaining healthy blood-clotting factors
Exercise and brain-stimulating activities
Heart-healthy diets (Mediterranean-style recommended)
These strategies benefit everyone, regardless of blood type.
Personalized Medicine Continues to Evolve
Researchers agree on one point: as science advances, healthcare will become increasingly personalized. Understanding how blood type interacts with vascular health, inflammation, and brain function could eventually guide targeted prevention strategies.
The Bottom Line
Blood type is not a definitive predictor of dementia. But early research suggests it may be one piece of a much larger puzzle. Knowing where you stand—and living proactively—may help protect cognitive health over the long term.
Disclaimer: This article is intended for general informational purposes only and should not be used as a substitute for professional medical advice. Please consult a qualified healthcare provider for guidance about any medical condition or lifestyle changes.
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