The inflammation paradox: Why are Tsimane protected against Western diseases while Westerners are not? [version 2; peer review: 2 approved, 1 approved with reservations]

Abstract

We here describe two apparent paradoxes concerning high CRP levels and NCD risk. One has emerged from observational studies in the Amazon region showing that the indigenous Tsimane in Bolivia appear protected against non-communicable diseases (NCDs) such as obesity, type 2 diabetes, and cardiovascular diseases despite increased inflammatory markers. These findings stand in contrast to Western societies, where an increasing body of evidence demonstrates that low-grade-inflammation is the driver of NCDs. The second paradox has emerged from two field studies (Eifel studies) conducted in 2013 and 2014 with Westerners who returned to a simulated Palaeolithic lifestyle in a National park for 4 days. We had detected elevated inflammation markers, despite otherwise anti-inflammatory effects of these interventions as indicated by metabolic blood parameters. We here propose three hypotheses for this second inflammatory paradox.