Dr Rangan Chatterjee
hosted by Rangan Chatterjee
We tested 4 claims from Dr Rangan Chatterjee against the research. 0 held up, 0 did not, and the rest are partly true or still too early to judge.
Dr. Tommy Wood
Neuroscientist and faculty member in pediatrics at the University of Washington
Partly
“A daily standard multivitamin can slow cognitive brain ageing by approximately two years.”
Dr. Tommy Wood (Neuroscientist and faculty member in pediatrics at the University of Washington) · Dr Rangan Chatterjee, September 2026 · watch the episode ↗︎ · stated with confidence
Several large randomised trials do indeed show a modest memory benefit from a daily multivitamin in older adults, and the figure of 'two years' falls within the range reported by the research (two to three years less decline). However, the claim is worded too broadly: the effect appears to occur mainly in people at risk of nutritional deficiencies or with a history of heart disease, not in well-nourished older adults in general. Moreover, the positive findings come largely from a single research programme, and independent confirmation is still needed before this can be presented as established fact.
Partly
“Lowering systolic blood pressure by around 10 points leads to a significant reduction in the risk of dementia.”
Dr. Tommy Wood (Neuroscientist and faculty member in pediatrics at the University of Washington) · Dr Rangan Chatterjee, September 2026 · watch the episode ↗︎ · stated with confidence
Lowering blood pressure demonstrably reduces the risk of strokes and cardiovascular events, and untreated high blood pressure in middle age clearly increases the likelihood of dementia later in life. However, the claim that a reduction of around ten points in systolic blood pressure leads to a substantial decrease in dementia risk cannot be firmly established on the basis of available research. The direction is plausible, the causal evidence specific to dementia is not yet watertight, and linking a precise figure such as ten points to an effect on dementia goes beyond what the studies show.
Will Bulsiewicz
Gastroenterologist and author
Partly
“Consuming fermented foods daily for eight weeks increases gut microbiome diversity and lowers inflammatory markers.”
Will Bulsiewicz (Gastroenterologist and author) · Dr Rangan Chatterjee, September 2026 · watch the episode ↗︎ · stated with confidence
Research shows that a diet rich in fermented foods can increase gut microbiome diversity and lower inflammatory markers, and there are randomised studies that support this. The direction of the claim is therefore correct, but the evidence comes mainly from smaller studies and does not apply equally to every fermented product. Moreover, the specific timeframe of eight weeks cannot be firmly established on the basis of available research, and the strongest results apply above all to kefir and yoghurt, not to all fermented foods without distinction.
Partly
“Repeated courses of antibiotics, formula feeding, and caesarean section are associated with an increased risk of immune-related conditions later in life.”
Will Bulsiewicz (Gastroenterologist and author) · Dr Rangan Chatterjee, September 2026 · watch the episode ↗︎ · stated with confidence
For repeated antibiotic use, research shows that it disrupts the gut microbiota and can thereby impair immune function, but a proven causal link to broader immune-related conditions later in life has not yet been established. The available research contains nothing to support formula feeding and caesarean section as risk factors for immune-related conditions, so those two parts of the claim cannot be assessed. The direction is partially correct for antibiotics, but the claim presents all three factors more confidently and more broadly than the evidence justifies.