Evidence on chronic ketosis in traditional Arctic populations

Was there a need for high carbohydrate content in Neanderthal diets?

“…However, their inference that Neanderthals had to consume 50–60 E% from carbohydrates appears at odds with the archeological evidence for high meat consumption, as they also acknowledge. To solve this apparent paradox, Hardy et al proposed three possibilities: Neanderthals were genetically adapted to a high‐meat diet, just as contemporary arctic populations are adapted to a high‐fat diet by a genetic variant of CPT1A which results in reduced hepatic fat oxidation and ketogenesis (O'Hearn, 2018b). However, this possibility is considered unlikely due to the spatiotemporal consistency of the archeological data. Neanderthals survived on a suboptimal low‐carbohydrate diet, but could not thrive.…”

“…Two other recent studies showed that there is a large population of individuals who voluntarily follow a long‐term hypercarnivorous diet because it makes them feel well and healthy (Lennerz et al, 2021; Protogerou et al, 2021). Finally, traditional populations such as the Inuit have been known for their low consumption of plants and may have thrived in a state of chronic ketosis despite their CPT1A variant (O'Hearn, 2018b). If it is indeed possible to thrive on a hypercarnivorous diet in our times (O'Hearn, 2020), the putative anomaly posed by Hardy et al between basic physiological carbohydrate requirements and the extensive archeological evidence would vanish.…”

Genetic variants for personalised management of very low carbohydrate ketogenic diets

“…Of particular interest was the arctic variant of CPT1A, which shows reduced ability to generate ketones in response to carbohydrate restriction. For the record, I had previously addressed the suggestion that chronic, high levels of ketosis could be dangerous, 2 an idea misattributed to Joshi et al 3 I had discussed alternative hypotheses, including enhanced protein tolerance and the role of high intake of polyunsaturated fat in enabling this adaptation. Verification of this idea is important in that it would immediately suggest a modification of ketogenic diets that could improve safety for this population.…”