Apolipoprotein E4 is associated with improved cognitive function in Amazonian forager-horticulturalists with a high parasite burden.
The apolipoprotein E4 (E4) allele is present worldwide, despite its associations with higher risk of cardiovascular morbidity, accelerated cognitive decline during aging, and Alzheimer 'S: disease (AD). The E4 allele is especially prevalent in some tropical regions with a high parasite burden. Equatorial populations also face a potential dual burden of high E4 prevalence combined with parasitic infections that can also reduce cognitive performance. We examined the interactions of E4, parasite burden, and cognitive performance in a traditional, nonindustrialized population of Amazonian forager-horticulturalists (N = 372) to test whether E4 protects against cognitive decline in environments with a heavy pathogen burden. Contrary to observations in industrial populations, older adult E4 carriers with high parasite burdens either maintained or showed slight improvements in cognitive performance, whereas non-E4 carriers with a high parasite burden showed reduced cognitive performance. Being an E4 carrier is the strongest risk factor to date of AD and cognitive decline in industrial populations; it is associated with greater cognitive performance in individuals facing a high parasite and pathogen load, suggesting advantages to the E4 allele under certain environmental conditions. The current mismatch between postindustrial hygienic lifestyles and active parasite-rich environs may be critical for understanding genetic risk for cognitive aging.-Trumble, B. C., Stieglitz, J., Blackwell, A. D., Allayee, H., Beheim, B., Finch, C. E., Gurven, M., Kaplan, H. Apolipoprotein E4 is associated with improved cognitive function in Amazonian forager-horticulturalists with a high parasite burden.
School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA; trumble@asu.edu. Center for Evolution and Medicine, Arizona State University, Tempe, Arizona, USA. Institute for Advanced Study in Toulouse, Toulouse, France. Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA. Department of Anthropology, University of California, Santa Barbara, Santa Barbara, California, USA. Department of Preventive Medicine, University of Southern California, Los Angeles, California, USA. Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA. Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California, USA. Dornsife College, University of Southern California, Los Angeles, California, USA. Department of Anthropology, University of California, Santa Barbara, Santa Barbara, California, USA. Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA.
