A large USC-led study found that the APOE ε4 gene variant — the strongest common genetic risk factor for late-onset Alzheimer's disease — may be linked differently to brain amyloid buildup in Hispanic older adults compared to non-Hispanic white older adults. Analyzing data from more than 17,000 participants across five major aging and Alzheimer's disease studies, researchers found that while APOE ε4 was associated with higher amyloid burden in both groups, the association was weaker among Hispanic participants. The findings suggest that cognitive impairment in Hispanic older adults may not always be driven by amyloid in the same way, and that other biological, vascular, or social factors may also contribute. The study underscores the need for more diverse populations in Alzheimer's research, particularly as anti-amyloid therapies become an increasingly central part of treatment.

Researchers studied the microbes associated with historical middens conserved in Greenland’s permafrost, left behind by Paleo-Inuit, ancient Norse, and early modern Inuit. These middens harbored biodiverse bacterial communities – including many unknown taxa – that were especially rich in human- and animal-associated groups. The authors concluded that microbial traces of human activities such as defecation, livestock farming, and seal hunting can linger for centuries in Arctic middens. They also found a wide range of antimicrobial resistance genes in the bacterial genomes. However, the limited outward spread of potential pathogens away from the frozen core of the middens means that they currently pose little risk to public health.