There has been an increased number of studies in recent years on the causes of Alzheimer’s disease and other age-related memory issues. New research published in September 2014 by Neurology now shows that the blood type of an individual may actually increase the risk for developing memory issues in the late stages of life. The study concluded that individuals with the blood type AB (the most uncommon of all blood types) are almost twice as likely to develop cognitive impairment compared to individuals with other blood types.
Cognitive decline is not the first disease that has been correlated to the blood type of an individual though. Researchers have already recognized relations between blood type and cardiovascular health. It has been noted in some studies that those with an O blood type had a lower risk of developing heart disease and having a stroke. It should also be noted that both heart disease and stroke increase the risk of memory loss and dementia later in life.
Academics at the University of Vermont College of Medicine delved further into this connection though. They began to inspect the connection between blood type and the prevalence of cognitive impairment. These experts conducted a huge study and analyzed data from more than 30,000 black and white adults living in the United States that had formerly been enrolled in an even larger study known as REGARDS (Reasons for Geographical and Racial Differences in Stroke).
It was shown that 495 of the subjects developed cognitive impairment over the 3.5 years that the study was conducted and matched these individuals to a similar group of 587 people who had absolutely no memory retention issues.
Their findings showed that six percent of the subjects who developed cognitive impairment were blood type AB. This is 150% higher than found in the rest of the US population at four percent. The experts then adjusted the findings for age, race, region and sex and it was discovered that those with the AB blood type were still 82% more likely to experience age related issues with memory, language and attention. Although these are all suggestive of the onset of dementia, it should be noted that the study did not at the risks for the advancement of dementia.
These scientists noticed something else as well. The levels of a clotting protein called factor VIII were also inspected in this study and it was shown that the higher the level of factor VIII the higher the risk for developing cognitive impairment later in life. It was also seen that the average level of this clotting protein were higher in those with blood type AB than those with O.
This may sound like a shocking discovery to you but previous studies have also revealed that those with type AB blood can have different blood clotting tendencies than those with other blood types. Furthermore, the researchers at University of Vermont had already found an increased risk of stroke with the AB blood type. The high level of factor VIII raises the chance of blood clots to form which in turn may also raise the cardiovascular disease and stroke risk of an individual.
“Our study looks at blood type and risk of cognitive impairment, but several studies have shown that factors such as high blood pressure, high cholesterol and diabetes increase the risk of cognitive impairment and dementia,” said Cushman, who headed researched at the University of Vermont. “Blood type is also related to other vascular conditions like stroke, so the findings highlight the connections between vascular issues and brain health.”
Even though this research is fascinating, the relationship shown in the data cannot conclude that AB blood type is the cause of cognitive decline in elderly. It does, however, warrant the need for further studies to be conducted.