As we age, our mental abilities begin to change. Our brains shrink, our cognition diminishes, and our reflexes slow. There are lots of factors that affect the rate of change in our brains. Evidence now suggests that our blood types may hold important information about how quickly our brains develop diseases.
Human blood is classified into four different types: A, B, AB, and O. Each type represents the existence of a different kind of protein on the surface of a person’s red blood cells. The differences between them may seem small, but scientists are beginning to find that each blood type may affect the risk of acquiring certain diseases. Two scientific studies from the past few years have looked specifically at the connection between cognitive health and blood type.
The first study was published in the July 2015 edition of Brain Research Bulletin. It found that people with an O blood type may have a lower risk of cognitive decline later in life than those with A, B, or AB blood types. O blood type is the most common type, found in about 45 percent of the US population.
The researchers made the discovery after analyzing the results of 189 MRI scans from healthy volunteers. When they measured the volume of gray matter in each volunteer, they found that individuals with an O blood type had more overall gray matter in the brain. Individuals with A, B or AB blood types, by contrast, had smaller grey matter volumes, particularly in the part of the brain that’s often most susceptible to damage from Alzheimer’s disease.