John Gilday
Mara Labs
John Gilday is associated with Mara Labs and has a research background in organic chemistry. His peer-reviewed publications focus on synthetic organic chemistry, including asymmetric synthesis, organolithium-mediated reactions, and the chemical synthesis of nitrogen-containing heterocycles such as aziridines, piperidines, and sparteine derivatives.
26 claims checked on air: 1 context 4 contradicted 6 overstated 11 supported 4 unverified
What they said on air - contradicted
In young people, exercise increases NRF2 expression, whereas in people over 60, over-exercising causes NRF2 levels to decline.
"Young people, you exercise, your NRF2 goes up like crazy. Um past 60 or so, NRF2 goes down if you over-exercise." (said at 0:32:27)
The speaker bundles two claims: that exercise robustly increases Nrf2 in young individuals, and that in adults over 60, over-exercising causes Nrf2 levels to decline. While acute exercise stimulates Nrf2 pathway activation and downstream antioxidant gene expression in young adults, evidence does not show that exercise causes Nrf2 levels to decline in older adults. Instead, randomized trials comparing adults aged 18–28 to adults aged 60 and older show that acute exercise still activates Nrf2 signaling in older adults, although the acute response is blunted or attenuated compared to younger individuals. Furthermore, sedentary older adults exhibit higher basal Nrf2 levels (reflecting baseline oxidative stress), and aerobic exercise training actually lowers basal Nrf2 while partially restoring its dynamic activation during exercise.
- supports: The impact of acute and chronic exercise on Nrf2 expression in relation to markers of mito… (European journal of applied physiology 2020) · cited 42x in the literature
"Nrf2, NRF-1, and HO-1 mRNA expression increased after acute exercise (p < 0.05), whereas the increase in superoxide dismutase 2 (SOD2) mRNA expression approached significance (p = 0.08)." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: Aerobic exercise training partially reverses the impairment of Nrf2 activation in older hu… (Free radical biology & medicine 2020) · cited 33x in the literature
"In older humans the Nrf2 response to a single bout of acute exercise is blunted compared to young indicating impaired redox signaling. ... Young had greater Nrf2 signaling response compared to older at pre-intervention (p = 0.05), whereas the older had significantly higher basal Nrf2 levels (p = 0.004). ET decreased basal Nrf2 expression compared to CON (p = 0.032) and improved the Nrf2 signaling response in both young and older (p < 0.05)." (abstract, results)
pubmedfull study (doi) - contradicts: Sulforaphane improves exercise-induced NRF2 signaling in older adults: an in vivo-ex vivo … (GeroScience 2026) · cited 2x in the literature
"Twenty-five older adults (12 men, 13 women; mean age: 67 ± 5 years) performed 30-min cycling exercise (AET). ... All treatments (SFN, EX, EX + SFN) increased NRF2 activation compared to CON (p < 0.05)." (abstract, results)
pubmedfull study (doi)
Sulforaphane stimulates bile salt biosynthesis.
"And it also induces um bile salts. That's the master control over bile salt biosynthesis, which is uh another way you protect against SIBO is uh bile salt production." (said at 0:48:20)
Preclinical studies show that sulforaphane and Nrf2 activation suppress rather than stimulate bile acid biosynthesis. In rodent models, pharmacological and genetic activation of Nrf2 downregulates CYP7A1 (cholesterol 7alpha-hydroxylase, the rate-limiting enzyme in bile acid synthesis) and reduces hepatic and serum bile acid concentrations. Furthermore, the master transcriptional regulator of bile acid synthesis and homeostasis is the farnesoid X receptor (FXR), not sulforaphane or Nrf2.
Black pepper used in curcumin formulations enhances bioavailability by aggravating and disrupting enterocytes, thereby increasing inflammation.
"HOST: They use black pepper and other things that just and they say, "Oh, we put black pepper in it so it'll absorb." That's just causing leaky gut. The black pepper is just aggravating the enterocytes, like you said. GUEST2: Yeah, and instead of decreasing your inflammation, it's increasing your inflammation." (said at 1:15:35)
The claim that black pepper (piperine) enhances curcumin bioavailability by aggravating or damaging enterocytes (causing 'leaky gut') and thereby increasing inflammation is contradicted by both pharmacokinetic and clinical trial evidence. Pharmacokinetic studies demonstrate that piperine enhances curcumin bioavailability primarily through the reversible inhibition of hepatic and intestinal glucuronidation and modulation of drug efflux transporters, without causing gut barrier disruption. Furthermore, a systematic review of randomized controlled trials examining curcumin combined with piperine found significant reductions in systemic inflammatory markers (such as CRP, hs-CRP, and IL-6) and oxidative stress across diverse clinical populations, rather than an increase in inflammation.
- contradicts: Curcumin-piperine supplementation modulates inflammation, oxidative stress, and cardiometa… (Frontiers in nutrition 2026)
"Fifteen out of twenty trials indicated significant decreases in inflammatory biomarkers [C-reactive protein (CRP), high-sensitivity CRP (hs-CRP), and interleukin-6 (IL-6)]... In a variety of clinical populations, curcumin-piperine supplementation consistently demonstrates anti-inflammatory, antioxidant, metabolic, and cardioprotective effects, with a good safety profile." (abstract, results and conclusions)
pubmedfull study (doi) - contradicts: Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. (Planta medica 1998) · cited 1959x in the literature
"In this study, the effect of combining piperine, a known inhibitor of hepatic and intestinal glucuronidation, was evaluated on the bioavailability of curcumin in rats and healthy human volunteers... Concomitant administration of piperine 20 mg produced much higher concentrations from 0.25 to 1 h post drug (P < 0.01 at 0.25 and 0.5 h; P < 0.001 at 1 h), the increase in bioavailability was 2000%. The study shows that in the dosages used, piperine enhances the serum concentration, extent of absorption and bioavailability of curcumin in both rats and humans with no adverse effects." (abstract, results)
pubmedfull study (doi)
Resveratrol acts as a selective agonist for estrogen receptor beta (ERβ).
"resveratrol is an estrogen receptor beta uh agonist uh selective agonist so that you know for the people that are worried about the alpha ER alpha issue, um a large number of the side effects from menopause are are because of the loss of estrogen receptor beta activation." (said at 1:20:23)
Pharmacological studies demonstrate that resveratrol is not a selective estrogen receptor beta (ERβ) agonist. In vitro receptor binding assays show that resveratrol binds both estrogen receptor alpha (ERα) and ERβ with comparable affinity (approximately 7,000-fold lower affinity than 17β-estradiol), unlike certain other phytoestrogens (such as genistein or S-equol) that exhibit preferential selectivity for ERβ. Resveratrol functions as a selective estrogen receptor modulator (SERM) with mixed agonist and antagonist properties across both ERα and ERβ depending on cell type, tissue context, and response elements, rather than acting as a subtype-selective ERβ agonist.
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