People with O type blood have more gray matter in their brain and may be more protected against conditions that cause cognitive decline, such as Alzheimer’s, than people with A, B, or AB blood types.
For a new study, researchers analyzed 189 Magnetic Resonance Imaging (MRI) scans from healthy volunteers and calculated the volumes of gray matter within the brain and the differences among blood types.
The findings, published in the Brain Research Bulletin, show that individuals with O blood have more gray matter in the posterior portion of the cerebellum.
People with A, B, or AB blood have smaller gray matter volumes in temporal and limbic regions of the brain, including the left hippocampus, which is one of the earliest parts of the brain damaged by Alzheimer’s disease.
Lower gray matter volume is normally seen in the brain as we age, but the differences are greater in people with blood types other than O, researchers said.
“The findings seem to indicate that people who have an O blood type are more protected against the diseases in which volumetric reduction is seen in temporal and mediotemporal regions of the brain like with Alzheimer’s disease for instance,” said research fellow Matteo De Marco.
“However additional tests and further research are required as other biological mechanisms might be involved.”
“What we know today is that a significant difference in volumes exists, and our findings confirm established clinical observations,” said Annalena Venneri, professor of neuroscience at the University of Sheffield.
“In all likelihood the biology of blood types influences the development of the nervous system. We now have to understand how and why this occurs.”
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