A 2025 human study of four geographically distinct populations investigated inflammation biomarkers:

“Inflammaging, an age-associated increase in chronic inflammation, is considered a hallmark of aging. However, there is no consensus approach to measuring inflammaging based on circulating cytokines.

We assessed whether an inflammaging axis detected in the Italian InCHIANTI dataset comprising 19 cytokines could be generalized to a different industrialized population (Singapore Longitudinal Aging Study) or to two indigenous, nonindustrialized populations: the Tsimane from the Bolivian Amazon and the Orang Asli from Peninsular Malaysia.

Much cytokine variation in these populations is probably due to the type and severity of current infections, not aging. Our results show that cytokines are not destiny with regard to inflammaging and chronic disease.

Even within industrialized populations, manifestation of inflammaging is highly heterogeneous. It may reflect immune dysregulation resulting from an evolutionary mismatch of physiology and environment, aligning with the notion that the hallmarks of aging are not universals, but rather common manifestations whose importance varies by context.

The Singapore Longitudinal Aging Study was similar to InCHIANTI except for IL-6 and IL-1RA. The Tsimane and Orang Asli showed markedly different axis structures with little to no association with age and no association with age-related diseases.

Inflammaging, as measured in this manner in these cohorts, appears to be largely a byproduct of industrialized lifestyles, with major variation across environments and populations.”

https://www.nature.com/articles/s43587-025-00888-0 “Nonuniversality of inflammaging across human populations” (not freely available) Thanks to Dr. Ian J. Wallace for providing a copy.

This study used the terms “industrialized” and “nonindustrialized” two dozen times without defining either, as if every reader knew what these researchers meant. Impreciseness wasn’t an accident, though. It invokes a meme rather than promote reader understanding. They did the same thing with not defining a significant biomarker, IL-IRA.

I’ll highlight one of the unmeasured and potentially important differences among these four populations, daily sunlight exposures. Although Singapore is one degree of latitude above the equator, sunlight availability doesn’t matter when the average 62-year-old retiree spends their days mostly indoors, and their nights viewing blue-light screens. What would be “industrialized” about this lifestyle?

Prevent your brain from shrinking studied brain volume effects of Tsimane diet and lifestyle.