Biological versus chronological aging as variable refinement for age discrimination (agism)
By Götz Kaufmann, 2015-07-11
On July 6, 2015, the Proceedings of the National Academy of Sciences of the United States of America (PNAS) has published online [and prior printing] the findings of a research on the "Quantification of biological aging in young adults" at Duke University, Kings College London, The Hebrew University of Jerusalem, the University of California, and the University of Otago under supervision of Daniel W. Belsky, PhD.
As the authors tell, the "studied aging in 954 young humans, the Dunedin Study birth cohort, tracking multiple biomarkers across three time points spanning their third and fourth decades of life. We developed and validated two methods by which aging can be measured in young adults, one cross-sectional and one longitudinal. Our longitudinal measure allows quantification of the pace of coordinated physiological deterioration across multiple organ systems (e.g., pulmonary, periodontal, cardiovascular, renal, hepatic, and immune function)." Therefore, they "applied these methods to assess biological aging in young humans who had not yet developed age-related diseases. Young individuals of the same chronological age varied in their 'biological aging' (declining integrity of multiple organ systems). Already, before midlife, individuals who were aging more rapidly were less physically able, showed cognitive decline and brain aging, selfreported worse health, and looked older." (p. 1) To measuring age, they "calculated each Dunedin Study member's Biological Age at age 38 y using the Klemera–Doubal equation (23) and parameters estimated from the NHANES-III dataset (26) for 10 biomarkers." (p. 6) Their findings are both quite enlightening and frightening. They could show that "Biological Age took on a normal distribution, ranging from 28 y to 61 y (M = 38 y, SD = 3.23)." (p. 6) This means that in the sample of researched, same aged people - all 38 years old - some have a biological age of only 28 years whereas some are 'already' aged as if they would be 61 years old.
What has this to do with Environmental Justice? Well, as has been discussed, discrimination has many faces far beyond gender and race related discrimination (cf. Kaufmann 2012: 212). Agism - thus the age related discrimination, disadvantage or vulnerability towards the distribution of environmental burdens and goods - is certainly one of the prominent ones, even though much less researched than gender and race related discrimination. These intersections between discrimination may be linked. One idea is to pool these into a global world system differential (WSD, Kaufmann 2014: 226-228). The WSD basically claims a structural discrimination - sometimes multiplied by various discriminations at once - within the world system' regime (in Foucault's meaning).
Even though the reasons for such aging haven't been revealed so far by the authors of the study, they recognized such social constructivist circumstances as possible explaining variables. As they state, a "blockade is that humans are subject to a range of complex social and genomic exposures impossible to completely simulate in animal experiments. If aging can be measured in free-living humans early in their lifespans, there are new scientific opportunities. These include testing the fetal programming of accelerated aging (e.g., does intrauterine growth restriction predispose to faster aging in young adulthood?); testing the effects of early-life adversity (e.g., does child maltreatment accelerate aging in the decades before chronic diseases develop?); testing social gradients in health (e.g., do children born into poor households age more rapidly than their age-peers born into rich ones and can such accelerated aging be slowed by childhood interventions?); and searching for genetic regulators of aging processes (e.g., interrogating biological aging using high throughput genomics)." (p. 6)
For environmental justice research, the second last consideration might be a reasonable link. If social class related connections can be found, maybe also as part of GIS data, the positive impact of the inclusion of such gerontological research findings into the environmental justice research theme must not be underestimated. The existing research on climate change vulnerability at Environmental Justice Institute for instance (CC-VISAGES and CC-VISAGES in Canada) would possibly benefit tremendously from such additive.
The reviewed study can be downloaded here.
Image: © PNAS