Document Type
Article
Publication Date
9-2-2020
Abstract
Background
In an energy-limited environment, caloric investments in one characteristic should trade-off with investments in other characteristics. In high pathogen ecologies, biasing energy allocation towards immune function over growth would be predicted, given strong selective pressures against early-life mortality.
Methodology
In the present study, we use flow cytometry to examine trade-offs between adaptive immune function (T cell subsets, B cells), innate immune function (natural killer cells), adaptive to innate ratio and height-for-age z scores (HAZ) among young children (N = 344; aged 2 months–8 years) in the Bolivian Amazon, using maternal BMI and child weight-for-height z scores (WHZ) as proxies for energetic status.
Results
Markers of adaptive immune function negatively associate with child HAZ, a pattern most significant in preadolescents (3+ years). In children under three, maternal BMI appears to buffer immune and HAZ associations, while child energetic status (WHZ) moderates relationships in an unexpected direction: HAZ and immune associations are greater in preadolescents with higher WHZ. Children with low WHZ maintain similar levels of adaptive immune function, but are shorter compared to high WHZ peers.
Conclusions
Reduced investment in growth in favor of immunity may be necessary for survival in high pathogen contexts, even under energetic constraints. Further, genetic and environmental factors are important considerations for understanding variation in height within this population. These findings prompt consideration of whether there may be a threshold of investment into adaptive immunity required for survival in high pathogen environments, and thus question the universal relevance of height as a marker of health.
Lay Summary
Adaptive immune function is negatively associated with child height in this high pathogen environment. Further, low weight-for-height children are shorter but maintain similar immune levels. Findings question the relevance of height as a universal health marker, given that costs and benefits of height versus immunity may be calibrated to local ecology.
Recommended Citation
Garcia, A. R., Blackwell, A. D., Trumble, B. C., Stieglitz, J., Kaplan, H., & Gurven, M. D. (2020). Evidence for height and immune function trade-offs among preadolescents in a high pathogen population. Evolution, Medicine, and Public Health, 2020(1), 86–99. https://doi.org/10.1093/emph/eoaa017
Peer Reviewed
1
Copyright
The authors
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Included in
Economic Theory Commons, Other Ecology and Evolutionary Biology Commons, Other Economics Commons, Population Biology Commons
Comments
This article was originally published in Evolution, Medicine, and Public Health, volume 2020, issue 1, in 2020. https://doi.org/10.1093/emph/eoaa017