EMBARGOED FOR RELEASE UNTIL 4 PM ET, July 15, 2015
Alzheimer鈥檚 May Affect the Brain Differently in African-Americans than European-Americans
MINNEAPOLIS -
Alzheimer鈥檚 disease may cause different changes in the brain, or pathologies, in African-Americans than in white Americans of European descent, according to a study published in the July 15, 2015, online issue of , the medical journal of the . 鈥淏ecause some studies suggest that Alzheimer鈥檚 disease is more common among older African-Americans than European-Americans, we wanted to see whether the brain changes caused by Alzheimer鈥檚 are different in these two racial groups,鈥 said study author Lisa L. Barnes, PhD, with Rush University Medical Center in Chicago. 鈥淪tudying how Alzheimer鈥檚 disease looks in the brain in individuals of different races may help us to further understand the disease and pinpoint strategies for prevention and treatment.鈥 The study included 41 African-Americans with a clinical diagnosis of Alzheimer鈥檚 dementia from the memory clinic, who had an autopsy of their brain performed after death. They were then compared to 81 deceased European-Americans who had Alzheimer鈥檚 dementia with the same level of disease severity and were of the same age, sex and education level. Researchers looked for typical signs of Alzheimer鈥檚 disease (plaques and tangles) as well as other brain changes that can cause dementia, such as infarcts (the brain changes associated with stroke) and Lewy bodies (associated with Lewy body or Parkinson鈥檚 disease). They noted whether people had just one pathology or more than one. They also looked at small and large blood vessel disease. Almost all participants in the study had Alzheimer鈥檚 disease in their brain. Only about half of the European-Americans had pure Alzheimer鈥檚 disease pathology (no additional pathologies contributing to dementia) whereas the rest had Alzheimer鈥檚 disease pathology with either infarcts or Lewy bodies. In contrast, less than 25 percent of the African Americans had pure Alzheimer鈥檚 disease pathology. On the other hand, almost three-quarters (71 percent) of African-Americans had Alzheimer鈥檚 disease pathology mixed with another type of pathology, compared to 51 percent of European-Americans. Clinical Alzheimer鈥檚 disease in African-Americans was much more likely to involve pathologies other than Alzheimer鈥檚 disease pathology. African-Americans also had more frequent and severe blood vessel disease. 鈥淥ur study has important clinical implications because it may suggest a need for different types of Alzheimer鈥檚 prevention and treatments in African-Americans. Indeed, current Alzheimer鈥檚 drugs primarily target specific Alzheimer pathologies in the brain. Given the mixed pattern of disease that we see in African American brains, it will be important to develop new treatments that target these other common pathologies, particularly for African-Americans,鈥 said Barnes. The study was supported by the National Institutes of Health and the Illinois Department of Public Health. To learn more about Alzheimer鈥檚 disease, please visit .