HoldsUp

Huberman Lab · 2026-08-03 · Andrew Huberman (host), Matthew (Max) Krummel

How Your Immune System Works & How to Improve It | Dr. Max Krummel

54 research-tied claims examined: 7 contradicted 2 overstated 7 context 37 supported 1 unverified

7 Contradicted by research
0:11:10Matthew (Max) Krummelcontradictedhigh

Gut bacteria synthesize key components of bile acids required for digesting animal fats.

"you can't digest animal fats if it weren't for the bugs the bacteria in your gut. They make some of the key components of of bile acids that allow you to digest animal fats." (said at 0:11:10)

The claim is biochemically and physiologically incorrect. Primary bile acids essential for emulsifying and digesting dietary fats (including animal fats) in the upper small intestine are synthesized de novo by hepatocytes in the host liver from cholesterol and conjugated to glycine or taurine. Gut bacteria do not synthesize the bile acids required for fat digestion; rather, bacteria in the distal intestine and colon metabolize primary bile acids into secondary bile acids (such as deoxycholic acid and lithocholic acid), which function predominantly as metabolic signaling molecules rather than digestive agents. Furthermore, germ-free animals lacking all gut microbiota produce primary bile acids and absorb dietary fats normally without significant impairment in baseline fatty acid absorption compared to conventional animals.

0:16:40Matthew (Max) Krummelcontradictedhigh

Skin cells may accumulate between 10,000 and 30,000 DNA mutations per cell per day from basic sun exposure.

"Like they say that on your skin, the cells of your skin may have somewhere between 10 and 30,000 mutations per cell per day. Just from like basic sun exposure." (said at 0:16:40)

The speaker conflates transient DNA damage (lesions) with permanent somatic mutations. Human cells experience an estimated 10,000 to 100,000 DNA damaging events (such as single-strand breaks, base loss/modification, and UV-induced photolesions) per cell per day. However, virtually all of these lesions are corrected by cellular DNA repair pathways (such as nucleotide excision repair and base excision repair). Only an infinitesimal fraction of unrepaired lesions ever becomes fixed as permanent somatic mutations; accumulating tens of thousands of fixed mutations per cell per day would rapidly destroy genomic integrity and cause immediate cell death. Whole-genome sequencing shows that even heavily sun-exposed human skin cells accumulate only several thousand somatic mutations in total across an entire lifetime, not per day.

0:25:29Matthew (Max) Krummelcontradictedmoderate

The small white spots that appear on human skin around age 40 to 50 are areas where the immune system wiped out precancerous or early cancerous melanocytes.

"one example that everybody sees when they get to be about 40 or 50 is these little white spots on your skin. And we think that those are places where the immune system has sensed a collection of cells that were precancerous, maybe they were even beginning of cancer, and has wiped them out. And so, you know, a lot of the origin of cancers in skin is melanin-producing cells like, you know, melanoma is what we call skin cancer. Those melanocytes that white area that's been wiped of a whole collection of melanocytes, and that's why it's white instead of as dark as the rest of your skin." (said at 0:25:29)

The small white spots that characteristically appear on sun-exposed skin in adults around age 40 and older are known clinically as idiopathic guttate hypomelanosis (IGH). Dermatological research shows that IGH is a benign consequence of photoaging, chronic ultraviolet (UV) radiation exposure, genetic predisposition, and cellular senescence of melanocytes (leading to structural abnormalities, decreased melanin synthesis, and impaired melanosome transfer to keratinocytes). There is no scientific evidence that these spots represent areas where the immune system cleared precancerous or early cancerous melanocytes; the speaker appears to confuse benign photoaging-related hypomelanosis (IGH) with distinct immune-mediated phenomena such as halo nevi or melanoma regression.

0:50:00Matthew (Max) Krummelcontradictedvery low

During sleep, tissues become populated by neutrophils originating from bone marrow that deposit collagen.

"And your tissues become populated with a bunch of neutrophils that come out of the bone marrow and seem to be depositing collagen around your body" (said at 0:50:00)

While circulating neutrophil counts and bone marrow egress/homing exhibit circadian and sleep-dependent rhythms, neutrophils do not deposit collagen. Extracellular matrix and collagen deposition are primarily carried out by fibroblasts and myofibroblasts, whereas neutrophils secrete matrix-degrading enzymes (such as neutrophil collagenase/MMP-8 and MMP-9) rather than synthesizing or depositing structural collagen.

0:38:45Matthew (Max) Krummelcontradictedmoderate

Historically, surgical removal of the thymus in children undergoing thoracic or exploratory heart surgery caused them to suffer and die from opportunistic bacterial and viral infections.

"There was this time when kids that had heart issues would come in for surgeries and they would discover this enormous whitish organ as a growth near the heart as they were cutting open. And all the autopsies up to that point had been done mostly with adults. And in adults, there's only this small little thing there. And so they're like, "Oh my god, part of the heart thing is this overgrown thing." They didn't really know what it did. And so they would remove it. And the kids then go home and it was usually exploratory heart surgery, but kids would go home and, far from dying of heart disease, many of them would die from opportunistic infections." (said at 0:38:45)

The speaker presents a distorted historical narrative conflating the historical concept of 'status thymolymphaticus' with congenital heart surgery. First, the thymus has been known to anatomy since antiquity; in pediatric cardiac surgery, routine or partial thymectomy was performed not because surgeons discovered an unexpected, mysterious tumor they mistook for cardiac pathology, but deliberately to gain surgical access to the heart and great vessels. Second, while infant thymectomy impairs naive T-cell output and accelerates immunosenescence, pediatric cardiac surgery patients who undergo thymectomy do not typically suffer or die from opportunistic infections post-discharge.

1:26:03Andrew Huberman (host)contradictedmoderate

Supplementing with nattokinase can reduce LDL cholesterol levels in the blood.

"As a result, I decided to start supplementing with nattokinase, which can naturally help reduce LDL cholesterol, and it did. In a follow-up test, I could confirm that this strategy worked. My blood lipids are now back exactly where I want them." (said at 1:26:03)

A systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating nattokinase supplementation found that it does not decrease LDL cholesterol levels. In pooled RCT data, low-dose nattokinase was associated with a slight increase in LDL cholesterol (mean difference 6.49 mg/dL) and total cholesterol, while higher doses showed no statistically significant effect on LDL or HDL cholesterol compared to control. Although some uncontrolled trials with very high doses (10,800 FU/day) and combination products (such as nattokinase combined with red yeast rice) have reported lipid improvements, rigorous randomized trials do not support the claim that nattokinase monotherapy reduces blood LDL cholesterol.

  • contradicts: Nattokinase Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-… (Reviews in cardiovascular medicine 2023) · cited 9x in the literature
    "Relatively low total dosage of nattokinase had a negative effect on blood total cholesterol (MD [mean difference] = 5.27, 95% CI [confidence intervals]: 3.74 to 6.81, p < 0.00001), high-density lipoprotein cholesterol (MD = -2.76, 95% CI: -3.88 to -1.64, p < 0.00001), and low-density lipoprotein cholesterol (MD = 6.49, 95% CI: 0.83 to 12.15, p = 0.02)... Nattokinase group with relatively high total dosage also had a higher total cholesterol (MD = 3.18, 95% CI: 2.29 to 4.06, p < 0.00001) than control interventions, but no significant differences were found in levels of high-density lipoprotein cholesterol and low-density lipoprotein cholesterol." (abstract, results)
    pubmedfull study (doi)
1:55:40Matthew (Max) Krummelcontradictedvery low

Injecting interferon-gamma into the bloodstream of healthy mice induces social isolation behavior, mediated by brain receptors for immune cytokines.

"There's an experiment that was done that involved injecting gamma interferon, which is one of the things your immune system makes when it's fighting off an infection, into the bloodstream of a mouse and then just watching it. And they become socially isolating from just the molecule that's made by the... lab that did this also showed that the brain has receptors for these immune molecules." (said at 1:55:40)

The speaker appears to refer to landmark neuroimmunology work on interferon-gamma (IFN-γ) and social behaviour (Filiano et al., Nature 2016), but inverts the direction of effect. Filiano et al. demonstrated that mice deficient in adaptive immunity or lacking IFN-γ exhibit impaired social preference and social deficits, whereas brain inhibitory neurons express IFN-γ receptors and respond to IFN-γ to enable normal social interaction. Delivering IFN-γ to IFN-γ-deficient mice rescued social behavior rather than inducing social isolation in healthy mice.

  • contradicts: Unexpected role of interferon-&#x3b3; in regulating neuronal connectivity and social behav… (Nature 2016) · cited 710x in the literature
    "Here we show that meningeal immunity is also critical for social behaviour; mice deficient in adaptive immunity exhibit social deficits and hyper-connectivity of fronto-cortical brain regions. Associations between rodent transcriptomes from brain and cellular transcriptomes in response to T-cell-derived cytokines suggest a strong interaction between social behaviour and interferon-γ (IFN-γ)-driven responses. Concordantly, we demonstrate that inhibitory neurons respond to IFN-γ and increase GABAergic (γ-aminobutyric-acid) currents in projection neurons, suggesting that IFN-γ is a molecular link between meningeal immunity and neural circuits recruited for social behaviour." (abstract, results, passage verified)
    pubmedfull study (doi)
2 Overstated
0:21:15Andrew Huberman (host)overstatedmoderate

Core body temperature must rise by approximately 1 to 3 degrees Fahrenheit upon waking.

"And in order to wake up feeling refreshed and energized, your body temperature actually has to increase by about 1 to 3°." (said at 0:21:15)

Human core body temperature exhibits a well-documented circadian oscillation where temperature reaches a nadir (minimum) during the second half of the sleep period (typically around 04:00–05:00) and rises across the morning on its ascending limb to promote alertness and wake maintenance. However, the total peak-to-trough amplitude across an entire 24-hour day in humans is only approximately 0.5 °C to 1.0 °C (~0.9 °F to 1.8 °F). Claiming that core body temperature must rise by '1 to 3 degrees' (particularly up to 3 °F) specifically upon waking overstates both the magnitude of the immediate morning temperature change (which is a fraction of the daily amplitude) and treats a correlational circadian phase marker as a strict physiological requirement.

2:01:33Matthew (Max) Krummeloverstatedhigh

Immune checkpoint blockade therapy leads to tumor disappearance in 50% of melanomas.

"I would say checkpoint blockade is one of those that you can take it and in 50% of melanomas, the tumor goes away and everything's great." (said at 2:01:33)

The claim overstates the degree of response. In advanced melanoma, dual immune checkpoint blockade (such as nivolumab plus ipilimumab in the landmark CheckMate 067 trial) achieves an objective response rate (ORR) of approximately 58% and a 5- to 6.5-year overall survival rate of around 50%. However, the overall response rate combines partial responses (tumor shrinkage >= 30%) with complete responses. Complete disappearance of tumors (complete response) occurs in only approximately 15% to 22% of treated patients, not 50%.

7 Needs context
0:12:35Matthew (Max) Krummelneeds contextmoderate

For the first six months of life, the human immune system is relatively poor at being trained on antigens.

"One of them is for the first 6 months or so, your immune system is pretty poor at being trained on things. And it's presumably we presume that for those first 6 months that's because your body's developing so fast that if you were to have a super active immune system, you might actually find yourself attacking yourself." (said at 0:12:35)

The claim captures the general biological rationale of early infant immunology but needs context. During early infancy (the first several months of life), the immune system is skewed toward immune tolerance, characterized by heightened naive CD4+ conversion to regulatory T cells (Tregs), dampened Th1 and cytotoxic effector responses, reduced memory formation, and reliance on maternal antibodies to avoid damaging inflammatory and autoimmune reactions to rapid physiological growth and colonizing commensals. However, characterizing the system as simply 'poor at being trained' is an oversimplification: infant immune systems can and do mount antigen-specific responses to vaccines (such as HepB, DTaP, and pneumococcal vaccines administered from birth and 2 months onward), though they typically require multiple doses or adjuvants due to this physiological tolerogenic bias.

0:40:10Matthew (Max) Krummelneeds contextmoderate

Developing T cells have a theoretical receptor diversity potential on the order of 10 to the 11th power.

"And so the T cells that come in there, they're T cells that are developing and they each have a possible 10 to the 11th different kinds of receptors to smell different things." (said at 0:40:10)

The speaker's estimate of 10^11 potential T-cell receptor (TCR) variants captures the vast diversity of the T-cell repertoire, though theoretical combinatorial potential and realized repertoire sizes differ. Through V(D)J recombination and junctional diversity during thymocyte development, theoretical TCR diversity is estimated to exceed 10^15 to 10^20 possible sequences. In practice, due to thymic selection and cellular constraints, an individual human maintains an estimated circulating naive TCR repertoire of approximately 10^8 (100 million) distinct clonotypes out of an organismal pool of roughly 10^11–10^12 total T cells.

0:49:50Matthew (Max) Krummelneeds contextmoderate

During sleep, circulating immune cells clear out of the bloodstream and migrate back into the bone marrow.

"and one of them is that a lot of your immune cells clear back to the bone marrow." (said at 0:49:50)

Circulating immune cells undergo pronounced circadian and sleep-dependent redistribution, but the specific destination and timing vary by cell subset and species. In humans, nocturnal sleep promotes the homing of naive and memory T cells to lymph nodes (facilitating immune surveillance and memory formation), whereas redistribution of certain leukocyte subsets to the bone marrow via CXCR4 upregulation is driven by daytime cortisol peaks during the active phase. In contrast, nocturnal animal models (e.g., mice) clear leukocytes and aged neutrophils back into the bone marrow during their rest/sleep phase (the light period). Thus, while sleep and circadian cycles govern immune cell clearance from circulation to tissues including lymph nodes and bone marrow, attributing generalized bone marrow clearance directly to human sleep conflates rest-phase rodent findings and specific leukocyte subset kinetics.

  • context: The contribution of sleep to the neuroendocrine regulation of rhythms in human leukocyte t… (Seminars in immunopathology 2022) · cited 53x in the literature
    "In addition, sleep increases levels of immunosupportive mediators, such as aldosterone and growth hormone, which are assumed to promote T-cell homing to lymph nodes, thus facilitating the initiation of adaptive immune responses during sleep. Taken together, sleep-wake behavior with its unique neuroendocrine changes regulates human leukocyte traffic with overall immunosupportive effects during nocturnal sleep. In contrast, integrin de-activation and redistribution of certain leukocytes to the bone marrow during daytime activity presumably serves immune regulation and homeostasis." (abstract, conclusions, passage verified)
    pubmedfull study (doi)
0:52:46Matthew (Max) Krummelneeds contextmoderate

Macrophages reside in the eye where they function to clear debris from the lens.

"I always like the story that that there's macrophages, immune cells, in your eye that are basically clearing the clearing the lens." (said at 0:52:46)

The claim refers to the established developmental role of ocular macrophages in clearing transient embryonic vascular structures and cellular debris surrounding the developing lens (such as the tunica vasculosa lentis and hyaloid vessels) to establish an unobstructed optical path for vision. However, the mature lens itself is an encapsulated, avascular, and immune-privileged structure lacking resident macrophages; the clearance of light-scattering organelles inside maturing lens fiber cells is mediated by cell-autonomous degradation pathways (e.g., autophagy and enzymatic organelle breakdown) rather than phagocytosis by intra-lenticular macrophages.

1:03:08Matthew (Max) Krummelneeds contexthigh

CAR-T cell therapies involve engineering T cells with specialized receptors to target tumors, but often fail in patients due to the immune system shutting down or cells failing to eliminate the tumor.

"these things called CAR-Ts, and Alex would have told you about these where you engineer your T cells and you get you give them special receptors that can get them to go into to eliminate tumors. But for whatever reason, they haven't worked in patients. They haven't worked. They haven't worked. They haven't worked. And T cell—the immune system gets turned off. These cells don't make it. They don't fail—they fail to eliminate the tumor." (said at 1:03:08)

Chimeric antigen receptor (CAR) T-cell therapy involves genetically modifying a patient's T cells to express synthetic receptors targeted against tumor antigens. The speaker correctly identifies key biological failure mechanisms: T-cell exhaustion, limited cell persistence, and an immunosuppressive tumor microenvironment ('the immune system gets turned off') frequently prevent sustained tumor eradication. However, the blanket assertion that they 'haven't worked in patients' requires important context: CAR-T therapies have achieved remarkable, durable responses and multiple FDA approvals for hematologic malignancies (e.g., leukemias, lymphomas, myeloma), whereas the limited efficacy and failure mechanisms described by the speaker apply predominantly to solid tumors and relapsed/refractory non-responders.

1:07:18Matthew (Max) Krummelneeds contexthigh

CRISPR gene editing technology was discovered through research on how bacteria use enzymes to remember foreign genetic sequences and defend against invaders.

"CRISPR, you know, that was people were studying like how do bacteria defend against other bacteria? Well, they use this—it turns out there's this enzyme and it remembers the sequence of this one bacteria that has come and invaded you before and then can like modify the genome and get rid of it and like kill it." (said at 1:07:18)

The speaker accurately describes the core adaptive immune mechanism of CRISPR-Cas—in which bacteria capture and store fragments of foreign genetic material (spacers) to recognize and enzymatically cleave matching invaders upon reinfection, a mechanism subsequently adapted into gene-editing tools. However, the speaker incorrectly describes the system as defending against 'other bacteria'; CRISPR naturally functions primarily to defend bacteria against bacteriophages (viruses) and mobile genetic elements such as plasmids.

2:12:05Matthew (Max) Krummelneeds contextmoderate

There are approximately seven or eight distinct subtypes of asthma, with variations including eosinophil-predominant or neutrophil-predominant profiles.

"Is there only one form of asthma? That's no, there's actually definitely there's seven or eight. And they have and that's why some people are, you know, like can take the inhalers and it works and other people can't. Some people they're very like chlorine sensitive. They go to a pool and it and and it's just like cold sensitive. So, there's there's variations on what sets up that inflammatory focus. And I would call it like an archetype. Some of them have lots of cells called eosinophils. Other ones have lots of cells called neutrophils." (said at 2:12:05)

Asthma is well established to be a heterogeneous umbrella syndrome rather than a single disease, comprising distinct clinical phenotypes and biological endotypes that explain variations in treatment responsiveness (e.g., standard steroid inhalers vs. targeted biologics). Classically, inflammatory subtyping categorizes asthma into four cytological phenotypes based on sputum/blood cell profiles: eosinophilic (Type 2-high), neutrophilic (non-Type 2), mixed granulocytic, and paucigranulocytic. While comprehensive cluster analyses (such as those from the SARP, ADEPT, and U-BIOPRED cohorts) and clinical taxonomies frequently delineate multiple sub-clusters and clinical phenotypes (ranging from 4 to 8+ distinct groups when incorporating age of onset, atopy, obesity, irritant/occupational triggers, and molecular signatures), there is no single universally standardized classification fixing the number of asthma subtypes at precisely seven or eight.

37 Supported by research
0:06:35Matthew (Max) Krummelsupportedmoderate

The human body contains approximately 10^11 T cells.

"your body is filled with 10 to the 11th or so T cells. Like a ton of different kinds of T cells." (said at 0:06:35)

A comprehensive quantitative census of immune cells in the human body (Sender et al., PNAS 2023) estimated that a standard adult human body contains approximately 1.8 × 10^12 total immune cells, of which lymphocytes make up about 40% (~7 × 10^11 cells). Because T lymphocytes make up the majority of lymphocytes across lymphoid and non-lymphoid tissues, the total T-cell pool is on the order of several hundred billion (~10^11 to 10^12 cells), matching the speaker's estimate of '10 to the 11th or so'.

0:06:40Matthew (Max) Krummelsupportedhigh

HIV specifically infects CD4 T cells and depletes them, leading to opportunistic infections, Kaposi's sarcoma, and dementia.

"the HIV virus infects T cells... And you had a subset of T cells that are called CD4 T cells. They're kind of a flavor of T cells. And the virus gets rid of those. So, HIV virus will infect the CD4 T cells and then you end up with not having them. And the manifestations of AIDS for those who weren't around during it, was it was just a ton of different opportunistic infections... Kaposi's sarcoma... Dementias in in people with HIV as well." (said at 0:06:40)

The speaker accurately describes the core immunopathology of HIV infection: HIV targets and infects CD4+ T lymphocytes, leading to their progressive depletion. This profound immunodeficiency is the hallmark of AIDS, manifesting clinically as classic opportunistic infections, malignancies such as Kaposi's sarcoma, and central nervous system complications including HIV-associated dementia.

0:11:55Matthew (Max) Krummelsupportedhigh

The human genome contains approximately 20,000 genes.

"we only have 20,000 genes in our genome. So there's only so much in a given life that we can do with those genes." (said at 0:11:55)

Current genomic annotations consistently estimate the number of human protein-coding genes to be approximately 19,000 to 20,000. While the human genome contains additional non-coding RNA genes and pseudogenes, the figure of approximately 20,000 genes is standard and accurate for protein-coding genes.

0:21:00Andrew Huberman (host)supportedmoderate

Core body temperature must drop by approximately 1 to 3 degrees Fahrenheit to fall asleep and remain in deep sleep.

"in order to fall asleep and stay deeply asleep, your body temperature actually has to drop by about 1 to 3°." (said at 0:21:00)

Circadian thermoregulatory research confirms that core body temperature declines by approximately 0.5°C to 1.5°C (roughly 1°F to 3°F) over the nocturnal sleep period. This drop is driven by selective peripheral vasodilation (heat dissipation) before and during sleep, which promotes sleep onset and is associated with entry into slow-wave (deep) sleep.

0:26:40Matthew (Max) Krummelsupportedmoderate

Wound healing in children is significantly faster and more efficient than in adults.

"I think their wound healing I mean, there's a group out of Stanford that studies this, but essentially, you know, wound healing in the young is quite a bit faster and more efficient, and there's many levels of that." (said at 0:26:40)

Extensive literature in wound biology, including prominent work from Stanford University (such as the Longaker laboratory investigating regenerative and age-related wound repair), demonstrates that wound healing in younger organisms and children is substantially faster and exhibits greater regenerative capacity across multiple cellular and tissue levels compared to adults and older individuals. In older cohorts, all main phases of cutaneous wound repair (re-epithelialization, granulation tissue formation, and wound closure) are consistently delayed compared to young subjects.

0:29:30Matthew (Max) Krummelsupportedmoderate

Nerve pain during herpes virus reactivation is largely caused by the immune system reacting to the virus exiting neurons and killing off those neurons.

"Like, for example, in herpes virus infection, it infects the nerves, and when people have emergence, they get nerve pain and worse. A lot of that is caused by the immune system reacting to the virus trying to get out and then killing off neurons." (said at 0:29:30)

The speaker's general description is broadly supported. In neurotropic herpesvirus reactivation (most notably varicella-zoster virus, an alphaherpesvirus), the virus reactivates in sensory ganglia and travels down nerve axons. The resulting acute and persistent nerve pain (such as postherpetic neuralgia) is driven by nerve inflammation, direct viral cytopathic effects, and immune-mediated damage/neuronal injury within sensory ganglia and peripheral nerves. However, studies examining human ganglia indicate the host immune response to VZV often involves non-cytolytic T-cell mechanisms rather than wholesale direct cytotoxic killing of all infected neurons, though inflammatory cell infiltration and associated neuronal damage/death remain central pathophysiological mechanisms of neuropathic pain.

0:04:05Matthew (Max) Krummelsupportedvery low

A population of immune cells resides in the heart to regulate cardiomyocyte function and eliminate their cellular byproducts.

"It's in your heart. It's, you know, regulating cardiomyocyte function. Those are the the muscle cells of your heart. They have to be cleaned up from time to time. So, there's a set of immune cells that will help get rid of their byproducts in the in the in the heart." (said at 0:04:05)

The speaker accurately describes the physiological role of resident cardiac macrophages. Published preclinical research demonstrated that resident macrophages in the myocardium maintain cardiomyocyte homeostasis and heart function by taking up and clearing cellular byproducts, specifically dysfunctional mitochondria and other cellular cargo ejected by cardiomyocytes within membranous particles (exophers / transmitophagy). Depletion of these cardiac resident macrophages in animal models leads to the accumulation of abnormal mitochondria, metabolic alterations, and ventricular dysfunction.

  • supports: A Network of Macrophages Supports Mitochondrial Homeostasis in the Heart. (Cell 2020) · cited 758x in the literature
    "While analyzing macrophages lodged within the healthy myocardium, we discovered that they actively took up material, including mitochondria, derived from cardiomyocytes. Cardiomyocytes ejected dysfunctional mitochondria and other cargo in dedicated membranous particles reminiscent of neural exophers... Depletion of cardiac macrophages or deficiency in the phagocytic receptor Mertk resulted in defective elimination of mitochondria from the myocardial tissue, activation of the inflammasome, impaired autophagy, accumulation of anomalous mitochondria in cardiomyocytes, metabolic alterations, and ventricular dysfunction." (abstract, results, passage verified)
    pubmedfull study (doi)
  • supports: Macrophages, Metabolism and Heterophagy in the Heart. (Circulation research 2022) · cited 52x in the literature
    "Cardiac macrophages surround cardiomyocytes and capture dysfunctional mitochondria that these cells eject to the milieu, effectively establishing a client cell-support cell interaction. We refer to this heterologous partnership as heterophagy. Notably, this process shares analogies with other biological systems, is essential for proteostasis and metabolic fitness of cardiomyocytes, and unveils a remarkable degree of dependence of the healthy heart on immune cells for everyday function." (abstract, results, passage verified)
    pubmedfull study (doi)
0:11:32Matthew (Max) Krummelsupportedmoderate

Eating sushi provides the human gut with bacteria that facilitate the absorption and digestion of nutrients from seaweed.

"If you eat sushi, you know, you've heard this probably, right? You get you get bacteria in your gut that can help you absorb the the the seaweed. You know, nutrients from seaweed." (said at 0:11:32)

Research demonstrates that consumption of seaweed (such as nori used in sushi) facilitated the horizontal gene transfer of carbohydrate-active enzymes (CAZymes, specifically porphyranases and agarases) from marine microbes (e.g., Zobellia galactanivorans) to resident human gut bacteria (such as Bacteroides plebeius). Metagenomic and biochemical studies have shown that these acquired genes allow human gut microbiota to catabolize otherwise indigestible red seaweed polysaccharides (porphyran), enabling energy and nutrient extraction from dietary seaweed.

0:20:05Andrew Huberman (host)supportedmoderate

Red light, near-infrared, and infrared light improve muscle recovery, wound healing, skin health, acne, pain, inflammation, mitochondrial function, and vision.

"red light, near infrared, and infrared light have been specifically shown to have positive effects on improving numerous aspects of cellular and organ health. These include faster muscle recovery, improved skin health, wound healing, improvements in acne, reduced pain and inflammation, improved mitochondrial function, and even improvements in vision." (said at 0:20:05)

Photobiomodulation (PBM) using red and near-infrared light has been extensively investigated across the claimed domains. Systematic reviews, randomized trials, and mechanistic studies demonstrate that red and near-infrared wavelengths target mitochondrial cytochrome c oxidase (complex IV) to increase ATP production, reduce inflammation, promote wound healing and skin repair, accelerate muscle recovery/reduce delayed-onset muscle soreness, and improve visual parameters in conditions such as dry age-related macular degeneration.

0:39:15Matthew (Max) Krummelsupportedhigh

Jacques Miller demonstrated that removing the thymus from newborn mice caused them to develop severe immune deficiency and succumb to bacterial infections.

"And so this guy named Jacques Miller, who's this nice codger in Australia. At the time he was in England, and he basically took a bunch of mice, and when they were newborn he removed their thymus, the same little whitish organ. And sure enough, those mice basically grew up okay, but then they all would succumb to bacterial infections." (said at 0:39:15)

Jacques Miller's landmark 1961 experiments in London (published in The Lancet) demonstrated that surgical removal of the thymus in neonatal mice led to severe immunological impairment (lymphocyte depletion, failure of skin graft rejection, and lack of antibody responses) and subsequent wasting disease with premature death due to common infections.

0:39:46Matthew (Max) Krummelsupportedhigh

T cells originate from hematopoietic stem cells in the bone marrow that travel through the blood to the thymus to develop and mature.

"the thymus is the place that makes all your T cells. And it comes from a kind of convoluted pathway. You remember how we were talking about how the stem cells of your immune system live in your bone? Well, there's stem cells that live in your bone, and they travel through your blood to the thymus and become T cells." (said at 0:39:46)

The speaker's statement accurately reflects established immunological science. Hematopoietic stem and progenitor cells originate in the bone marrow, migrate via the bloodstream, and colonize the thymus, where they undergo lineage commitment, differentiation, and maturation into mature T cells.

0:41:10Matthew (Max) Krummelsupportedhigh

The human thymus has its highest output of T cells in early childhood (from infancy through age 4-5) and then progressively involutes and shrinks with age, significantly reducing new T cell output.

"So your thymus has this huge output. Really from three to six months old into your four or five years of age and tapering, your body makes tons of T cells... the thymus involutes. It gets super, super small, so that in aged people it's tiny. And so it's not putting out new T cells." (said at 0:41:10)

The speaker accurately describes the well-established physiology of thymic development and age-associated involution. In humans, thymic output of naive T cells is highest during infancy and early childhood (establishing the baseline peripheral T-cell repertoire). With age, the thymus undergoes progressive involution characterized by loss of thymic epithelial cells, fatty replacement, and severe shrinkage, leading to a marked reduction in de novo T-cell production in older adults.

0:54:07Andrew Huberman (host)supportedhigh

AG1 Pro contains 5 grams of creatine monohydrate per serving to support muscle strength, performance, and brain health.

"Each serving has 5 grams of creatine monohydrate to support muscle strength and performance as well as brain health." (said at 0:54:07)

A standard daily dose of 3 to 5 grams of creatine monohydrate is well established to increase muscle creatine stores, thereby enhancing muscle strength, lean mass accretion, and high-intensity exercise performance. Furthermore, clinical and physiological literature supports its emerging benefits for brain health, neuroprotection, and cognitive function.

0:54:20Andrew Huberman (host)supportedmoderate

Calcium HMB supports muscle recovery and reduces muscle breakdown.

"Calcium HMB to support muscle recovery and reduce muscle breakdown" (said at 0:54:20)

Systematic reviews and meta-analyses of randomized controlled trials support that beta-hydroxy-beta-methylbutyrate (HMB), commonly administered as calcium HMB (CaHMB), aids muscle recovery and attenuates exercise-induced muscle damage and breakdown, as demonstrated by significant reductions in post-exercise serum markers of muscle damage such as creatine kinase (CK) and lactate dehydrogenase (LDH).

0:54:27Andrew Huberman (host)supportedmoderate

Zinc carnosine supports and improves the integrity of the gut lining.

"and zinc carnosine to support and improve the lining of your gut." (said at 0:54:27)

Randomized human crossover trials demonstrate that zinc-L-carnosine (polaprezinc) preserves intestinal mucosal integrity, stabilizes tight junctions, and prevents increases in gut permeability induced by stressors such as non-steroidal anti-inflammatory drugs (indomethacin) and heavy physical exercise. Mechanistic in vitro and in vivo studies further confirm its pro-migratory, reparative, and cytoprotective properties along the gastrointestinal tract.

0:48:24Andrew Huberman (host)supportedvery low

Major histocompatibility complex (MHC) molecules and immune cells are actively functional throughout the lifespan within the central nervous system.

"Well, when I started in neurobiology, the central nervous system was considered an immune-privileged organ. There weren't supposed to be immune cells there. And thanks to the beautiful work of Carla Shatz with the major histocompatibility complex work and Ben Barres... We now know that the immune system is actively alive in the central nervous system throughout the whole lifespan serving critical roles." (said at 0:48:24)

The speaker accurately describes a well-established shift in neuroscience pioneered in part by Carla Shatz and Ben Barres. Historically, the central nervous system (CNS) was viewed as strictly immune-privileged and devoid of immune molecule functions. Groundbreaking research demonstrated that major histocompatibility complex class I (MHCI) molecules, complement proteins, and immune cells (such as microglia) are active within the CNS throughout development, adulthood, and disease, where they play critical non-classical roles in synaptic plasticity, activity-dependent circuit remodeling, and synaptic pruning. Because the foundational evidence for these specific molecular pathways derives from mechanistic animal models and in vitro neurobiology, certainty is rated very low under GRADE clinical criteria, despite high consensus in basic neuroscience.

1:01:47Matthew (Max) Krummelsupportedhigh

The thymus is structurally composed of thymic epithelial cells forming a matrix where progenitor cells arriving from the bone marrow reside and mature.

"the thymus is both the cells that come into it from the bone marrow, so it as an organ it has contents. But, its structure are some thymic epithelial cells that a kind of cell that make a matrix that all those cells live in and they get educated in." (said at 1:01:47)

The speaker's description matches fundamental immunological science. The thymus stroma is primarily composed of thymic epithelial cells (along with mesenchymal and endothelial cells), which form the three-dimensional structural microenvironment. Bone marrow-derived progenitor cells seed the thymus, where they reside, differentiate, and undergo selection and maturation (education) into functional T cells.

1:07:50Matthew (Max) Krummelsupportedvery low

Blocking a negative regulatory molecule on T cells using an antibody activates T cells and causes tumors in mice to regress.

"I injected a mouse with an antibody that I'd made. It was against a molecule on T cells. And I shown already in the lab that that molecule caused the T cells to get more activated when you blocked it. And and we did a series of like other mouse experiments of like all kinds of diseases and it, you know, kept humming up the T cells. And then and, you know, Jim—I got that. I said, "We've got some tumors in the fridge." And so we set up that experiment. And, you know, you injected this antibody and the tumors melted." (said at 1:07:50)

The speaker describes the landmark preclinical discovery that blocking the negative regulatory molecule CTLA-4 on T cells with an antibody enhances T-cell activation and causes established tumors to regress in mice. This was demonstrated in a 1996 Science paper by Leach, Krummel, and Allison (PMID 8596936), where in vivo administration of an anti-CTLA-4 monoclonal antibody led to rejection of pre-established murine tumors and long-lasting antitumor immunity. Because the body of evidence directly testing this specific claim consists of preclinical animal experiments, the GRADE certainty is rated very low.

1:15:48Andrew Huberman (host)supportedvery low

Transplanting calbindin-expressing neurons from the suprachiasmatic nucleus into the brain can restore circadian rhythmicity in an arrhythmic animal.

"you can take just one subpopulation of these neurons, the calbindin-expressing suprachiasmatic nucleus neurons—it's like 5% of the total neurons in this already tiny cluster of neurons—and you can transplant them pretty much anywhere, and certainly in the brain, and you'll restore the circadian rhythm of an arrhythmic animal." (said at 1:15:48)

Animal research in hamsters has shown that the calbindin-D28K-containing subpopulation of the suprachiasmatic nucleus (SCN) is necessary and sufficient to restore circadian locomotor rhythmicity. SCN tissue grafts containing calbindin-positive cells successfully restored circadian rhythms when transplanted into SCN-lesioned arrhythmic animals, whereas grafts lacking this subnucleus failed to do so, with the strength of the restored rhythm correlating with the number of calbindin-positive cells. Because the evidence is derived exclusively from animal models, the GRADE certainty is very low.

1:18:24Matthew (Max) Krummelsupportedvery low

Pancreatic tissue transplanted under the kidney capsule receives sufficient blood flow to survive and function.

"if you take the pancreas, you famously put it underneath the kidney capsule. Kidney has kind of like a skin around it. You can tuck some some pancreatic cells in there. And they're super happy. They love that. They get all the blood flow they need and it seems to be just right for them." (said at 1:18:24)

Preclinical animal models have established the subcapsular space of the kidney as a standard experimental site for pancreatic islet and tissue transplantation. Studies in rodents demonstrate that pancreatic tissue grafted under the renal capsule undergoes rapid revascularization via host cortical and capsular vascular networks within days, restoring sufficient perfusion and endocrine function to reverse experimental diabetes. Evidence is graded as very low certainty because this transplantation site is primarily used in preclinical animal research rather than standard clinical human transplantation.

1:18:45Matthew (Max) Krummelsupportedhigh

Type 1 diabetes is an autoimmune condition caused by the immune system attacking and destroying the pancreas.

"Diabetes, for those who don't know, type 1 diabetes is caused by the immune system that gets too active against the pancreas. It's autoimmunity. It's where it's now saying the pancreas is is not self. It's something foreign and it wipes it out" (said at 1:18:45)

Type 1 diabetes is well-established as a chronic autoimmune disease in which the immune system targets and destroys self-tissue—specifically the insulin-producing beta cells of the pancreatic islets of Langerhans, leading to insulin deficiency and hyperglycemia. While the speaker colloquially refers to destroying 'the pancreas' rather than specifying pancreatic beta cells, the description of type 1 diabetes as an autoimmune destruction of pancreatic tissue is medically accurate.

1:20:11Matthew (Max) Krummelsupportedvery low

In a study by the Rolls lab, chemogenetically reactivating insular cortex neurons that fired during mouse colitis triggered the immune system to recreate inflammatory infiltration in the gut.

"There's a very nice Israeli group that did this, Rolls lab that did very nice study where they induced into the guts of mice inflammatory bowel disease. They fed them a really kind of weird sugar that causes the bowel to puncture and then they get a really bad, you know, stomach ache. Um, a stomach ache and inflammatory bowel disease, diarrhea. And in that period they used, you know what DREADDs are. So they marked, for the crowd it's they used a way to mark all the neurons that were firing during that period in the insular cortex. And then later they could fire them like after the mouse had recovered, and they saw evidence that the immune system was resetting up itself in the gut as if it had just been punctured" (said at 1:20:11)

The speaker accurately describes a landmark 2021 study by the Rolls laboratory (Koren et al., Cell, PMID 34752731). In the study, mice were given dextran sulfate sodium (DSS, a sulfated polysaccharide) to induce colitis. Neurons active during inflammation in the insular cortex were captured using FosTRAP and chemogenetically reactivated with DREADDs after the mice recovered, which was sufficient to re-induce the peripheral inflammatory immune state in the gut. Because this evidence comes exclusively from animal/mechanistic experiments, the GRADE certainty is very low.

  • supports: Insular cortex neurons encode and retrieve specific immune responses. (Cell 2021) · cited 339x in the literature
    "Using activity-dependent cell labeling in mice (Fos TRAP ), we captured neuronal ensembles in the InsCtx that were active under two different inflammatory conditions (dextran sulfate sodium [DSS]-induced colitis and zymosan-induced peritonitis). Chemogenetic reactivation of these neuronal ensembles was sufficient to broadly retrieve the inflammatory state under which these neurons were captured." (abstract, passage verified)
    pubmedfull study (doi)
1:17:54Matthew (Max) Krummelsupportedhigh

Tissue-resident T cells permanently reside within specific tissues to provide localized protection rather than circulating continuously through blood and lymphatics.

"there's T cells that lodge in particular settings and they, you know, act to protect that tissue and they and they're resident cells of those tissues. They never leave." (said at 1:17:54)

The speaker's statement accurately describes tissue-resident memory T (TRM) cells. TRM cells represent a distinct, non-circulating lineage of memory T lymphocytes that establish long-term residence in peripheral barrier tissues (such as the skin, lungs, and gut) and internal organs, where they provide rapid, localized immune protection against reinfection rather than continuously recirculating through the blood and lymphatic system.

1:19:44Matthew (Max) Krummelsupportedvery low

The insular cortex can modulate and program peripheral organ immune states via the vagus nerve.

"how your insular cortex can program your immune state into organs and can via the vagus can essentially program the immune system." (said at 1:19:44)

The claim is supported by rodent neuroimmunology research (such as Koren et al., Cell 2021 from Asya Rolls' lab), which demonstrated that neuronal ensembles in the insular cortex encode representations of peripheral inflammatory/immune states (e.g., colitis or peritonitis) and that reactivation of these insular neurons can retrieve and modulate specific peripheral immune responses. However, certainty is graded as very low because this evidence comes entirely from preclinical animal models (mice) and mechanistic studies rather than human clinical data.

  • supports: Insular cortex neurons encode and retrieve specific immune responses. (Cell 2021) · cited 339x in the literature
    "Here, we show that the brain's insular cortex (InsCtx) stores immune-related information. Using activity-dependent cell labeling in mice (Fos TRAP ), we captured neuronal ensembles in the InsCtx that were active under two different inflammatory conditions (dextran sulfate sodium [DSS]-induced colitis and zymosan-induced peritonitis). Chemogenetic reactivation of these neuronal ensembles was sufficient to broadly retrieve the inflammatory state under which these neurons were captured." (abstract, results, passage verified)
    pubmedfull study (doi)
1:23:02Andrew Huberman (host)supportedhigh

Acute stress and short-term elevations in cortisol boost immune function, in contrast to chronic stress which suppresses immunity.

"we know that chronic stress impedes immunity. We also know that acute stress boosts it. And that's something that, you know, with all due respect to my colleagues who've focused on the ill effects of chronically elevated cortisol, like the the immune-enhancing effects of acute cortisol and stress are are really important" (said at 1:23:02)

The host's statement accurately summarizes the established psychoneuroimmunology paradigm regarding the contrasting effects of acute versus chronic stress on the immune system. A landmark meta-analysis of over 300 empirical human studies by Segerstrom and Miller (2004) demonstrated that acute stressors lasting minutes are associated with the adaptive upregulation of natural immunity parameters, whereas chronic stressors lead to broad suppression of both cellular and humoral immune function.

1:30:37Matthew (Max) Krummelsupportedmoderate

Introducing genes into cells using viral vectors or plasmids can cause engineered tissues to express foreign antigens that trigger immune rejection upon transplantation.

"So one of the challenges of tissue engineering is if you want to bring in new genes, the vector, the material that the the surrounding, whether you're bringing it using a virus to, you know, to bring it into those cells that you're going to now put into the person, whether it's a virus or a small piece of DNA called plasmid, you effectively are giving that a new bit of identity. And when you go to transplant that organ back in, it's seen as foreign. And it's just like you just put an infected cell in you, you know, as far as the immune system knows, all of a sudden there's a cell with a huge number of new things being expressed, and some of them viral, literally." (said at 1:30:37)

The speaker accurately explains a standard challenge in gene therapy and tissue engineering: introducing foreign genetic material via viral vectors (which carry immunogenic capsids and viral components) or plasmid DNA triggers innate immune sensing pathways, antigen presentation, and adaptive immune responses that can lead to immune-mediated clearance or graft rejection upon transplantation.

1:32:30Matthew (Max) Krummelsupportedlow

In mouse punch-biopsy studies, wound healing operates along a spatial gradient where distinct cell layers perform different functions and inner cells instruct outer cells.

"We did a study of wound healing some years ago. And if you have a wound in a mouse that's maybe just a like, you know, if you ever have a melanoma removed, they do a punch biopsy. It's a little circle. So you can do that in the back of a mouse and then you can watch the wound healing happen. There's zones within there where certain biology is really important to be happening... The cells like one layer back are doing certain things, but the other ones behind that are also induced to do something. The wound isn't just this area. It's actually sensed all like a gradient almost like the neurons. And so these cells need to do different things than these cells." (said at 1:32:30)

The speaker describes experimental wound healing models (such as full-thickness punch/excisional wounds in mice) analyzed with spatial transcriptomics and multi-omics, showing that wound healing is orchestrated across spatial gradients with distinct concentric or layered microenvironments where specific cell populations perform distinct migratory, proliferative, and signaling roles. Preclinical spatial profiling studies in mouse wound models confirm that injury induces spatially zoned transcriptional states and localized cell-cell signaling gradients across wound margins. Because the evidence comes primarily from animal experimental models and spatial transcriptomic platforms, the GRADE certainty is rated as low.

1:35:45Matthew (Max) Krummelsupportedhigh

Vaccines consisting of tumor-specific proteins and peptides can stimulate immune cells to target cancer cells.

"there's really good data that you can promote more immune cells against the tumor by making a vaccine that consists of some of the proteins and peptides that are unique to the tumor and not different from you. And you introduce those as if you would introduce the virus or anything in a in a childhood vaccine, similar concept." (said at 1:35:45)

Extensive clinical trial data confirm that therapeutic cancer vaccines formulated with tumor-specific neoantigen proteins or synthetic peptides elicit robust, tumor-targeted T-cell responses in patients across multiple cancer types (e.g., melanoma, glioma, and Lynch-syndrome-associated cancers).

1:41:43Matthew (Max) Krummelsupportedvery low

In mouse immunization experiments, modifying the vaccine administration schedule can still achieve equivalent immune protection.

"if you've done enough mouse experiments as I have, you know that when you vaccinate on a slightly different schedule, you can still end up with the same outcome, you know, that is protection, you know, with slightly different schedules." (said at 1:41:43)

Preclinical murine immunization studies demonstrate that modifying vaccination schedules (such as altering intervals between prime and booster doses) can yield comparable levels of humoral and cellular immune responses. For example, testing short-interval (21-day) versus long-interval (56-day) prime-boost vaccination in BALB/c mice resulted in comparable CD8+ T-cell magnitudes and antibody levels. Because the evidence base consists of animal experiments, GRADE certainty is very low.

  • supports: Short- and Long-Interval Prime-Boost Vaccination with the Candidate Vaccines MVA-SARS-2-ST… (Viruses 2023) · cited 8x in the literature
    "We immunized BALB/c mice using 21-day (short-interval) or 56-day (long-interval) prime-boost vaccination protocols and analyzed spike (S)-specific CD8 T cell immunity and humoral immunity. The two schedules induced robust CD8 T cell responses with no significant differences in their magnitude. Furthermore, both candidate vaccines induced comparable levels of total S, and S2-specific IgG binding antibodies... Overall, we found very comparable immune responses following short- or long-interval immunization." (abstract, results, passage verified)
    pubmedfull study (doi)
1:47:50Matthew (Max) Krummelsupportedhigh

Immune checkpoint inhibitors provide roughly a 50% response or cure rate in patients with melanoma.

"it's still the case that if you come in with melanoma, even though there's only a 50% chance you're going to be cured, which is great—it used to be zero with these drugs—you still take 100% of the market takes that drug. Well, because the 50% that aren't going to respond, they don't know who they are, and so everybody takes it." (said at 1:47:50)

Phase 3 randomized controlled trial evidence (CheckMate 067) confirms that dual immune checkpoint inhibition (nivolumab plus ipilimumab) achieves a 5-year overall survival rate of 52% in patients with advanced melanoma, supporting the speaker's statement that there is roughly a 50% response/long-term survival rate.

1:52:14Andrew Huberman (host)supportedhigh

Measles infection can cause brain inflammation (encephalitis).

"The rise in measles is scary. People say, "Well, measles, I used to have measles parties." Talk to somebody who had massive inflammation and brain inflammation from measles. Not a pretty picture." (said at 1:52:14)

Measles infection is a well-established cause of severe central nervous system inflammation (encephalitis). Neurological complications of measles include acute measles encephalitis/acute disseminated encephalomyelitis, measles inclusion-body encephalitis in immunocompromised individuals, and subacute sclerosing panencephalitis (SSPE), a fatal chronic encephalitis occurring years after infection.

1:54:27Matthew (Max) Krummelsupportedvery low

Autism-like phenotypes are modeled in mice by inducing maternal immune activation through bacterial or immune challenge during pregnancy.

"if you wanted to induce autism in mice, people do it by injecting a bacterial infection into the mom when she's pregnant. Which tells you that an immune challenge can affect the neurons of a developing pup." (said at 1:54:27)

The speaker accurately describes the maternal immune activation (MIA) rodent paradigm. In experimental neuroscience, gestational immune challenge via bacterial components like lipopolysaccharide (LPS) or viral mimetics like poly(I:C) injected into pregnant dams is widely established to induce core autism-like behavioral phenotypes (e.g., impaired social interaction, altered vocalizations, and repetitive behaviors) and neurodevelopmental alterations in offspring.

2:10:32Matthew (Max) Krummelsupportedmoderate

In lupus, there is a familial mutation in a B-cell receptor that normally turns off the immune system, leading to susceptibility to autoantibodies.

"There's um, you know, lupus, there's a familial mutation in a a receptor that's on a B cell that normally helps turn off the immune system. And it's defective, and so those those people are susceptible to getting what are called autoantibodies." (said at 2:10:32)

The speaker accurately describes the mechanism involving inhibitory receptors on B cells—specifically FcγRIIB (encoded by FCGR2B)—in systemic lupus erythematosus (SLE). FcγRIIB is the primary inhibitory Fc receptor expressed on B lymphocytes that functions to dampen B-cell receptor signaling and terminate immune activation. Inherited genetic polymorphisms and loss-of-function variants in FCGR2B impair this inhibitory checkpoint, predisposing carriers to B-cell hyperactivation, loss of self-tolerance, and elevated production of pathogenic autoantibodies in both humans and animal models.

2:13:00Matthew (Max) Krummelsupportedhigh

Anti-TNF therapy blocks a cytokine and provides effective clinical responses for certain patients with inflammatory bowel disease.

"And and and you know this in the clinic because inflammatory bowel disease, you asked about drugs, is a good case where there's a couple different drugs that for some patients work really well. Anti-TNF therapy, for example, something that it blocks a cytokine. And some people with IBD, this is like really bad diarrhea and it's and manifests in very very painful um, you know, some people they there's a so, there starts to be classes of patients that have responses to these things." (said at 2:13:00)

Anti-tumor necrosis factor (anti-TNF) therapies, such as infliximab and adalimumab, are monoclonal antibodies that bind and neutralize the pro-inflammatory cytokine TNF-α. High-quality systematic reviews and randomized controlled trials confirm that anti-TNF agents induce and maintain clinical response and remission in subsets of patients with inflammatory bowel disease (both Crohn's disease and ulcerative colitis).

2:15:43Matthew (Max) Krummelsupportedhigh

The sickle cell gene mutation found in people of sub-Saharan African descent provides protection against malaria.

"the argument for why we would ever have a sickle cell gene. This is the one that causes people to have sickle cell anemia, and it's a lot of sub-Saharan African gene people from that origin have this is that it's actually defensive against malaria." (said at 2:15:43)

Extensive epidemiological and evolutionary genetics research confirms that carrying the sickle cell mutation (heterozygous sickle cell trait, HbAS), which is highly prevalent in populations of sub-Saharan African descent, provides substantial protection against severe Plasmodium falciparum malaria and malaria-related mortality (conferring approximately 75% to 90% protection against severe or complicated disease and hospital admissions).

2:17:41Matthew (Max) Krummelsupportedmoderate

Individual metabolic enzymes vary such that individual vitamin requirements can differ substantially from average recommended dietary guidelines.

"the the differences in your and my vitamin requirements is going to be quite profound because the metabolic enzymes we have for the vitamins that we might take in are going to be different between us. And so these FDA limits, these these numbers are averages. Some people may need five times that amount of, you know, vitamin X, others may need a fifth." (said at 2:17:41)

Nutrigenetics and biochemistry demonstrate that common single-nucleotide polymorphisms and genetic variations in metabolic enzymes and transporter proteins (such as MTHFR, G6PD, ALDH, and PEMT) alter enzyme kinetics, such as decreasing binding affinity (increasing Km) for vitamin-derived cofactors (e.g., FAD, NAD, folate cofactors). These individual genetic variations directly affect micronutrient metabolism and can substantially increase or alter individual requirements relative to standard population dietary guidelines (such as RDAs/DRIs).

2:14:39Matthew (Max) Krummelsupportedhigh

Anti-interleukin-17 (anti-IL-17) therapies are used as an effective medical treatment for psoriasis.

"I think it's like interleukin-17 or something now. Like the treatment, they have some good shampoos for that. So, but— And anti-interleukin-17." (said at 2:14:39)

Anti-interleukin-17 (anti-IL-17) biologics (such as secukinumab, ixekizumab, bimekizumab, and brodalumab) are well-established and highly effective medical treatments for moderate-to-severe plaque psoriasis. A Cochrane network meta-analysis of 179 randomized controlled trials involving over 62,000 patients found high-certainty evidence that anti-IL-17 therapies significantly increase the proportion of patients achieving clear or almost clear skin (PASI 90) compared to placebo and standard non-biological therapies.

1 No source found (not proven false)
0:51:27Andrew Huberman (host)unverifiedvery low

Periorbital puffiness and bags under the eyes caused by sleep deprivation are directly due to the pooling and impaired clearance of lymphatic fluid.

"everybody has bags under their eyes and looks like when they are sleep deprived. They sleep for a night or two and it goes away. That's clearly accumulation of lymph. We we actually know that. That's just lymph fluid that's not being cleared, and it might not even be the brain's glymphatic clearance system. It's just there's a bunch of lymph pooling under your eyes." (said at 0:51:27)

No published scientific records directly verifying the claim that under-eye puffiness and bags caused by sleep deprivation are directly due to the pooling and impaired clearance of lymphatic fluid were located. While sleep deprivation is known to affect facial appearance (such as causing transient periorbital puffiness or dark circles), dermatological literature generally attributes transient infraorbital swelling and discoloration to multifactorial vascular and interstitial fluid dynamics (such as venous pooling in thin eyelid tissues) and gravitational redistribution, rather than confirmed isolated impairment of lymphatic clearance.

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.