11 Needs context
Skin cancer patients have relatively low levels of vitamin D rather than elevated levels.
"But he also pointed out that if skin cancer was directly related with sunlight, then we should find in skin cancer patients, you know, very high levels of vitamin D. In actual fact, they've got relatively low levels of vitamin D." (said at 0:12:53)
The relationship between vitamin D levels and skin cancer depends heavily on whether levels are measured prospectively as a marker of sun exposure or cross-sectionally at the time of cancer diagnosis. In patients diagnosed with cutaneous malignant melanoma, systematic reviews and meta-analyses show a significantly higher prevalence of vitamin D deficiency and lower mean 25(OH)D levels compared to controls, with lower levels correlating with worse prognostic features (e.g., greater Breslow thickness and ulceration). However, large prospective meta-analyses show that pre-diagnostic circulating 25(OH)D levels are positively associated with an increased risk of developing melanoma and keratinocyte cancers (basal cell and squamous cell carcinoma), primarily serving as a biomarker of cumulative ultraviolet radiation exposure.
- supports: The association between serum vitamin D level and risk and prognosis of melanoma: a system… (Journal of the European Academy of Dermatology and Venereology : JEADV 2020) · cited 37x in the literature
"However, the prevalence of vitamin D deficiency was significantly higher in patients with melanoma than that in controls (odds ratio, 2.115; 95% CI, 1.151-3.885)." (abstract, results, passage verified)
pubmedfull study (doi) - contradicts: 25-Hydroxyvitamin D status, vitamin D intake, and skin cancer risk: a systematic review an… (Scientific reports 2020) · cited 73x in the literature
"Circulating level of 25(OH)D was associated with higher risks of melanoma (SRR (95% CI) per 30 nmol = 1.42 (1.17-1.72)) and keratinocyte cancer (KC) (SRR (95% CI) per 30 nmol/L = 1.30 (1.13-1.49))." (abstract, results)
pubmedfull study (doi) - supports: Malignant Melanoma: Vitamin D Status as a Risk and Prognostic Factor - Meta-analyses and S… (Anticancer research 2025) · cited 3x in the literature
"Patients with melanoma had significantly lower mean 25(OH)D levels compared to healthy controls, and there was a non-significant trend toward an increased melanoma risk in patients with vitamin D deficiency (≤20 vs. >20 ng/ml)." (abstract, results, passage verified)
pubmedfull study (doi)
Pre-treatment with red light on a small area of the back reduces the subsequent postprandial blood glucose spike in humans by just over 20%.
"The result when we gave people a burst of red light beforehand to stimulate their mitochondria was super clear. It wasn't ambiguous. The blood glucose levels went up, but they didn't peak anywhere near as seriously as they did without the red light... and the reduction in the spike was of the order of—it was just over 20% if I remember correctly." (said at 0:34:40)
The speaker is referring to their 2024 study (Powner & Jeffery, PMID 38378043) evaluating 670 nm photobiomodulation prior to an oral glucose tolerance test in healthy human subjects. The study found that a 15-minute exposure to 670 nm red light reduced total blood glucose elevation integrated over 2 hours by 27.7%, which closely matches the speaker's recollection of 'just over 20%'. However, the peak maximum glucose spike was only reduced by 7.5%, meaning the speaker slightly conflated the overall 2-hour postprandial area under the curve reduction with peak spike reduction. Furthermore, evidence is from a single small pilot study in healthy volunteers.
The Environmental Working Group reported that over 122 million Americans drink tap water containing high levels of chemicals known to cause cancer.
"The Environmental Working Group has also shown that over 122 million Americans drink tap water with high levels of chemicals known to cause cancer." (said at 0:50:16)
The Environmental Working Group (EWG) published cumulative cancer risk assessments (e.g., Evans et al., 2019, Heliyon) analyzing tap water monitoring data from tens of thousands of community water systems serving hundreds of millions of Americans. While EWG reports that over 100 million Americans are exposed to drinking water containing carcinogenic contaminants (such as arsenic, disinfection byproducts, chromium-6, and radioactive elements) at levels posing lifetime cancer risks above 1-in-a-million or 1-in-100,000 benchmarks, these 'high levels' reflect EWG's own strict, non-enforceable health guidelines rather than violations of enforceable federal drinking water standards (Maximum Contaminant Levels under the Safe Drinking Water Act), which most of these water systems fully meet. Furthermore, these figures are derived from modelled cumulative theoretical lifetime excess cancer risks rather than direct epidemiological measurements.
- context: Cumulative risk analysis of carcinogenic contaminants in United States drinking water (Heliyon 2019) · cited 73x in the literature
"Cumulative risk analysis of contaminant occurrence in United States drinking water for the period of 2010–2017 indicates that over 100,000 lifetime cancer cases could be due to carcinogenic chemicals in tap water. The majority of this risk is due to the presence of arsenic, disinfection byproducts and radioactive contaminants. For different states within the U.S., cumulative cancer risk for drinking water contaminants ranges between 1 × 10 −4 and 1 × 10 −3 , similar to the range of cumulative cancer risks reported for air pollutants." (abstract, results, passage verified)
openalexfull study (doi)
A brief exposure to 670 nanometer deep red light improves color vision threshold in humans by approximately 20% across the population.
"We then gave them a burst of red light to improve their mitochondria in cells that are very mitochondrial dependent. And we then brought them back and we found the threshold had changed. The threshold had improved in every one of those subjects but one... If you look over the population, the size of the effect is around 20%." (said at 0:55:15)
The speaker is describing findings from studies led by Glen Jeffery's laboratory (e.g., Shinhmar et al., 2020, 2021) investigating deep red light (670 nm) photobiomodulation on retinal photoreceptors. Brief exposure (e.g., 3 minutes) significantly improved color contrast sensitivity thresholds (specifically along the tritan/blue-yellow axis) by roughly 17-20%. However, this effect is restricted to older adults (aged ~40 years and older) experiencing age-related mitochondrial decline; the studies showed no meaningful improvement in younger individuals (<40 years). Thus, 'across the population' requires the qualification that it applies to aging populations rather than younger individuals.
Red light photobiomodulation produces its greatest physiological effect in the morning, between perceived sunrise and approximately 11:00 AM, in flies, mice, and humans.
"Very clear. Again, same in flies, mice, and humans. Your biggest effect is always in the morning and it's always generally just before perceived sunrise up until about 11:00." (said at 1:05:13)
Research from Glen Jeffery's laboratory demonstrated that 670 nm red light photobiomodulation significantly increased ATP production and shifted the ATP/ADP ratio in Drosophila melanogaster specifically during morning hours (tested at 8:00 AM and 11:00 AM), whereas treatment at other times of day had no effect. While time-of-day sensitivity to red light photobiomodulation is observed in animal models and human visual acuity pilot studies, describing this morning window (sunrise to 11:00 AM) as a universal rule ("always") across all species and physiological outcomes overstates the limited experimental contexts in which it has been directly tested.
Mitochondria produce more ATP in the morning than at any other time of day.
"You're making more ATP, this petrol that mitochondria make, in the morning than at any other time." (said at 1:06:26)
Mitochondrial dynamics, oxidative phosphorylation, and ATP generation are regulated by the circadian clock and exhibit diurnal rhythms aligned with the active phase (daytime in humans, nighttime in nocturnal animals). However, asserting that mitochondrial ATP production peaks specifically in the morning over any other time of day is an oversimplification. Diurnal peaks in mitochondrial respiration and metabolic capacity vary across tissues and are heavily influenced by the timing of feeding, physical activity, and light exposure, often peaking across the active period rather than universally in the early morning.
Approximately 20% of people who live to age 100 will have macular degeneration.
"If I get you all to live to 50, uh say if I get you all to live to 100 years, probably 20% of you will have macular degeneration." (said at 1:11:08)
The speaker's estimate that ~20% of centenarians have macular degeneration captures the substantial burden of age-related macular degeneration (AMD) in extreme old age, though published data indicate the actual prevalence of AMD in people aged 100 and older is typically even higher (around 30% to 40% or more). A retrospective study of centenarians aged ≥100 years found a 40% prevalence of macular degeneration.
Low-level red light exposure increases serum cytokine expression, which acts protectively.
"we found that cytokine expression in the serum changed a lot... increase in cytokine expression at low levels is protective." (said at 1:15:45)
The claim that low-level red light therapy increases serum cytokine expression protectively requires essential context. Photobiomodulation does not cause a generalized increase in serum cytokines (which would signify systemic inflammation). Instead, human trials demonstrate an immunomodulatory effect: red and near-infrared light selectively downregulates pro-inflammatory cytokines (such as IL-6, IL-8, and TNF-α) while selectively increasing specific anti-inflammatory and regulatory cytokines, such as IL-10 and TGF-β1.
- context: Effects of low-level laser therapy on the serum TGF-β1 concentrations in individuals… (Photomedicine and laser surgery 2014) · cited 14x in the literature
"Comparing the differences in TGF-β1 levels between the L group (874.9±541.7 pg/mL) and the P group (-128.4±832.8 pg/mL) revealed that there was a statistically significant increase in TGF-β1 levels 30 days post-intervention in group L compared with the placebo group (p=0.0379)." (abstract, results)
pubmedfull study (doi) - context: Effects of photobiomodulation and a physical exercise program on the expression of inflamm… (Advances in rheumatology (London, England) 2021) · cited 28x in the literature
"there was a significant increase in IL-10 concentration of EAP (p < 0.05) and higher value compared to CG (p < 0.001) the 8-week post-treatment." (abstract, results)
pubmedfull study (doi) - context: Photobiomodulation Improves Serum Cytokine Response in Mild to Moderate COVID-19: The Firs… (Frontiers in immunology 2022) · cited 22x in the literature
"During the study period, in PBM group, there was a significant decrease in serum levels of IL-6 (-82.5% +/- 4, P<0.001), IL-8 (-54.4% ± 8, P<0.001), and TNF-α (-82.4% ± 8, P<0.001)" (abstract, results)
pubmedfull study (doi)
Retinal mitochondria in mice show decreased membrane potential and reduced respiration in real time under standard domestic- or commercial-level LED lighting.
"when we use LEDs, the light found in LEDs, when we use them, certainly we use them on on the retina looking at mice, we can watch the mitochondria gently go downhill. They're far less responsive. They Their membrane potentials are coming down. The mitochondria are not breathing very well. Can watch that in real time under LED lighting. And LED lighting at the same energy levels that we that we would find in a domestic or or a commercial environment." (said at 1:15:00)
The speaker (Glen Jeffery) describes findings from broadband near-infrared spectroscopy (NIRS) studies measuring in vivo retinal mitochondrial metrics in real time. Published research from his group (e.g., Kaynezhad et al., 2022) demonstrated that exposure to short-wavelength blue light (~420 nm, a component prominent in typical white LEDs) at environmental energy levels induced real-time metabolic instability in retinal cytochrome-c-oxidase and blood oxygenation metrics in animals, indicating disrupted respiration and ATP production. However, broadband NIRS in live animals monitors the redox state/oxidation of cytochrome-c-oxidase (complex IV) and hemodynamics, rather than directly tracking mitochondrial membrane potential in real time, and the published real-time studies isolated specific short wavelengths (420 nm blue light) rather than testing full-spectrum domestic LED fixtures directly.
Mitochondria respond less positively to a compressed array of LEDs compared to incandescent light with a smooth, continuous spectrum.
"we now have found that the mitochondria knows that it's a it's a compressed load of LEDs because if you put people under a compressed series of LEDs like that, you don't get the same response or the same positive effect as you do if you put them under an incandescent light where the spectrum is totally smooth." (said at 1:32:40)
Research demonstrates that standard visible light-emitting diodes (LEDs, ~350–650 nm) lack the longer red and near-infrared wavelengths (670–1500+ nm) present in incandescent light and daylight. These longer wavelengths stimulate mitochondrial cytochrome c oxidase and respiration, whereas the prominent short/blue wavelengths in typical LED profiles can suppress respiration. Supplementing narrow-spectrum LED exposure with broad, continuous-spectrum light that includes near-infrared has been shown to improve mitochondrial-dependent physiological endpoints like retinal contrast sensitivity.
Plant foliage reflects significant amounts of infrared light rather than absorbing it as heat.
"The other thing that we've not touched on, which is, I think, very important in the architectural world and the school world, is that all plant matter reflects infrared light. You grab a plant out here in California where maybe it's 80 degrees, the leaf is not hot. Why does that happen? It's because it reflects infrared light." (said at 1:52:40)
Plant leaves exhibit high reflectance and low absorption in the near-infrared (NIR) spectrum (~700–1100 nm), primarily due to light scattering within the mesophyll cellular structure, which prevents unnecessary heat absorption from non-photosynthetic solar radiation. However, while high NIR reflectance reduces solar heat load, the primary active physiological mechanism maintaining leaf coolness below ambient air temperature during warm conditions is evaporative cooling via stomatal transpiration.
- supports: Leaf optical properties reflect variation in photosynthetic metabolism and its sensitivity… (Journal of Experimental Botany 2011) · cited 321x in the literature
"In this study, fresh-leaf reflectance spectroscopy (λ=450-2500 nm) and a partial least-squares regression (PLSR) analysis were used to estimate key determinants of photosynthetic capacity... Most of the wavelengths selected were correlated with known absorption features related to leaf water content, nitrogen concentration, internal structure, and/or photosynthetic enzymes." (abstract, results)
openalexfull study (doi) - supports: Leaf optical properties in higher plants: linking spectral characteristics to stress and c… (American Journal of Botany 2001) · cited 929x in the literature
"In all cases, the maximum difference in reflectance within the 400-850 nm wavelength range between control and stressed states occurred as a reflectance increase at wavelengths near 700 nm. In studies that included transmittance and absorptance as well as reflectance, maximum differences occurred as increases and decreases, respectively, near 700 nm." (abstract, results, passage verified)
openalexfull study (doi)
Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.