Studies of indigenous hunter-gatherer populations like the Hadza in Tanzania and rural agrarian groups like the Yoruba find that Alzheimer's and vascular dementia are exceptionally rare.
"when researchers study indigenous groups such as the Hadza hunter-gatherer tribe in Tanzania or rural agrarian populations like the Yoruba, they find that Alzheimer's and vascular dementia are exceptionally rare." (said at 1:16:12)
The claim partially reflects published literature but misattributes findings to the Hadza. The landmark Indianapolis-Ibadan Dementia Project demonstrated that Yoruba living in Ibadan, Nigeria had significantly lower prevalence (1.41% vs. 6.24%) and annual incidence (1.15% vs. 2.52%) of Alzheimer's disease compared to African Americans in Indianapolis (PMID: 7573588, PMID: 11176911). However, no formal epidemiological studies have quantified Alzheimer's or vascular dementia prevalence in the Hadza hunter-gatherers of Tanzania; the speaker likely conflated Hadza metabolic/activity research with recent dementia research on indigenous subsistence populations such as the Bolivian Tsimane and Moseten, who were found to have exceptionally low dementia prevalence (~1.2%, PMID: 35262289).
- supports: Incidence of dementia and Alzheimer disease in 2 communities: Yoruba residing in Ibadan, N… (JAMA 2001) · cited 391x in the literature
"The age-standardized annual incidence rates were significantly lower among Yoruba than among African Americans for dementia (Yoruba, 1.35% [95% confidence interval [CI], 1.13%-1.56%]; African Americans, 3.24% [95% CI, 2.11%-4.38%]) and for AD (Yoruba, 1.15% [95% CI, 0.96%-1.35%]; African Americans, 2.52% [95% CI, 1.40%-3.64%])." (abstract, results, passage verified)
pubmedfull study (doi) - context: Prevalence of dementia and mild cognitive impairment in indigenous Bolivian forager-hortic… (Alzheimer's & dementia : the journal of the Alzheimer's Association 2023) · cited 50x in the literature
"Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n = 169; crude prevalence = 0.6%, 95% CI: 0.0, 3.2), all age ≥ 80 years. Age-standardized MCI prevalence was 7.7% (95% CI: 5.2, 10.3) in Tsimane and 9.8% (95% CI: 4.9, 14.6) in Moseten." (abstract, results)
pubmedfull study (doi) - supports: Prevalence of Alzheimer's disease and dementia in two communities: Nigerian Africans and A… (The American journal of psychiatry 1995) · cited 467x in the literature
"The age-adjusted prevalence rates of dementia (2.29%) and Alzheimer's disease (1.41%) in the Ibadan sample were significantly lower than those in the Indianapolis sample, both in the community-dwelling subjects alone (4.82% and 3.69%, respectively) and in the combined nursing home and community samples (8.24% and 6.24%, respectively)." (abstract, results, passage verified)
pubmedfull study (doi)
Studies show that in individuals with chronic fatigue syndrome, inflammatory markers and energetic stress signals skyrocket after exercise, leading to post-exertional malaise.
"And and there's some studies that show increased inflammation. So, those signals of energy resistance, increased energy friction in the body, uh go up after exercise in a normal person. In these people with chronic fatigue, it seems like they can skyrocket and then that leads to this uh post-exertional malaise." (said at 2:22:00)
While individuals with ME/CFS exhibit altered metabolic and physiological responses to exercise—including heightened oxidative stress, impaired antioxidant responses, and altered immune gene expression—systematic reviews of exercise-challenge studies consistently show that circulating pro- and anti-inflammatory cytokines do not surge or 'skyrocket' after exercise compared to healthy controls, nor do circulating cytokines reliably explain post-exertional malaise.
- contradicts: Altered immune response to exercise in patients with chronic fatigue syndrome/myalgic ence… (Exercise immunology review 2014) · cited 98x in the literature
"Compared to the normal response of the immune system to exercise as seen in healthy subjects, patients with CFS have a more pronounced response in the complement system (i.e. C4a split product levels), oxidative stress system (i.e. enhanced oxidative stress combined with a delayed and reduced anti-oxidant response), and an alteration in the immune cells' gene expression profile (increases in post-exercise interleukin-10 and toll-like receptor 4 gene expression), but not in circulating pro- or anti-inflammatory cytokines." (abstract, results, passage verified)
pubmed - contradicts: Chronic fatigue syndrome and circulating cytokines: A systematic review. (Brain, behavior, and immunity 2015) · cited 172x in the literature
"Following physical exercise there were no differences in circulating cytokine levels between cases and controls and exercise made no difference to already elevated TGF-β concentrations. The finding of elevated TGF-β concentration, at biologically relevant levels, needs further exploration, but circulating cytokines do not seem to explain the core characteristic of post-exertional fatigue." (abstract, results)
pubmedfull study (doi) - contradicts: Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: cas… (Clinical and experimental immunology 2017) · cited 23x in the literature
"There were no differences between groups in changes to TGF-β protein concentrations after either commuting or exercise. All other cytokine protein and RNA levels were similar between cases and controls. Post-exertional symptoms and perceived effort were not associated with any increased cytokines." (abstract, results)
pubmedfull study (doi)