HoldsUp

William Li

William Li is a medical researcher who discusses the relationship between diet, gut health, and mental well-being. His peer-reviewed research primarily focuses on wound healing, tissue engineering, and regenerative medicine. He has co-authored clinical trials evaluating skin constructs, tissue allografts, and therapeutic agents for the treatment of diabetic foot ulcers and venous leg ulcers.

17 claims checked on air: 2 context 5 overstated 8 supported 2 unverified

What they said on air

0:00:40overstatedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Amentoflavone reduces anxiety.

"Amentoflavone actually lowers anxiety." (said at 0:00:40)

Evidence that amentoflavone reduces anxiety is limited entirely to preclinical animal models; there are no published human clinical trials evaluating its anxiolytic effects. In rodent behavioral assays (such as the elevated plus maze, hole-board test, light/dark box test, and stress-induced hyperthermia models), isolated amentoflavone demonstrated anxiolytic-like activity that appears to involve ionotropic GABA(A) receptor signaling. However, pharmacokinetic studies suggest that amentoflavone crosses the blood-brain barrier poorly in vivo, and whether these preclinical behavioral findings translate to anxiety reduction in humans remains unestablished.

0:05:05supportedmoderateYour Diet Is Secretly Destroying Your Mental Health (Science

The human small intestine is approximately 22 feet long.

"Small intestines is a long snaky tube like your garden hose, 22 ft." (said at 0:05:05)

The statement that the human small intestine is approximately 22 feet long aligns well with published anatomical and surgical measurements. In living adults, total small bowel length shows natural inter-individual variation, with systematic reviews and large surgical cohorts reporting mean lengths typically between 506 cm and 795 cm (approximately 16.6 to 26.1 feet), placing 22 feet (~6.7 meters or 670 cm) directly within the standard anatomical range.

0:07:13unverifiedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Between 80% and 90% of the vagus nerve fibers run upwards from the gut to the brain rather than downwards.

"80 to 90% of those nerves run upwards to the brain, not just downwards." (said at 0:07:13)

No published record matching the specific claim that 80% to 90% of vagus nerve fibers run upwards (afferent) from the gut to the brain rather than downwards was located; this does not prove the claim false.

0:18:31supportedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

In vitro studies show that applying ellagic acid or microbiome short-chain fatty acids to cultured inflammatory cells suppresses inflammatory activation.

"How do we know this? Because if you actually grow inflammatory cells in a petri dish in a tissue culture and you put ellagic acid in there, they will stop having a riot. They'll calm down. If you actually put the short-chain fatty acids of the gut microbiome in the same dish, they'll also calm down." (said at 0:18:31)

In vitro experimental models support the speaker's claim that both ellagic acid and gut microbiome-derived short-chain fatty acids (such as butyrate) suppress inflammatory activation in cultured immune cells. Studies using lipopolysaccharide (LPS)-stimulated macrophage cell lines (e.g., RAW 264.7) demonstrate that ellagic acid significantly attenuates pro-inflammatory cytokines such as TNF-α, IL-6, and prostaglandin E2. Similarly, applying short-chain fatty acids like butyrate downregulates inflammatory signaling pathways (such as NF-κB) and suppresses the production of pro-inflammatory cytokines and chemokines. Because this evidence is derived entirely from pre-clinical in vitro cell culture models, certainty is graded as very low.

0:18:47overstatedlowYour Diet Is Secretly Destroying Your Mental Health (Science

Clinical data shows that eating approximately one cup of strawberries per day over a couple of weeks lowers depression, improves cognition, and specifically improves memory.

"Now, what's interesting is the clinical data also shows that people who eat strawberries, about a cup of strawberries a day over the course of a couple of weeks, will also change mental state. It'll actually lower depression, improve cognition, specifically improve memory." (said at 0:18:47)

A 2023 randomized controlled trial evaluated daily strawberry supplementation (whole-fruit strawberry powder equivalent to one cup of fresh fruit) in overweight, middle-aged adults with insulin resistance and subjective cognitive decline. The study reported a modest reduction in depressive symptoms (p = 0.04) and reduced memory interference (p = 0.02) relative to placebo. However, the trial lasted 12 weeks (three months), not 'a couple of weeks', was conducted in a specific small cohort with pre-existing metabolic and cognitive risk factors, and represents preliminary evidence rather than definitive clinical proof for the general population.

0:20:11needs contextmoderateYour Diet Is Secretly Destroying Your Mental Health (Science

Studies at the University of Massachusetts showed that pesticides sprayed on apples penetrate 20% deep into the skin of the apple.

"So again, it turns out studies at UMass, University of Massachusetts, have studied if you take regular pesticides, spray them on an apple like in a conventional farm, basically the pesticides will penetrate 20% deep into the skin of the apple." (said at 0:20:11)

A 2017 study conducted at the University of Massachusetts Amherst (Yang et al.) evaluated the penetration of pesticides into apples and the efficacy of various washing agents. The researchers found that after 24 hours of exposure, 20% of the applied amount of the systemic fungicide thiabendazole (and 4.4% of the non-systemic insecticide phosmet) had penetrated into the apples. The speaker slightly mischaracterizes the metric by describing the 20% figure as a depth percentage ('penetrate 20% deep into the skin') rather than the fraction of applied pesticide quantity that entered the fruit tissue.

0:20:30overstatedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Ursolic acid improves cerebral blood flow and improves cognition.

"And so too is the ursolic acid, which improves blood flow, which improves brain blood flow, which improves cognition." (said at 0:20:30)

The claim states that ursolic acid improves cerebral blood flow and thereby improves cognition. While preclinical animal studies (e.g., in rodent models of Alzheimer's disease or diabetes) suggest that ursolic acid can exert neuroprotective effects and improve performance on memory tests, no clinical trials or published scientific records demonstrate that ursolic acid increases cerebral blood flow or enhances cognition in humans. Stating these effects definitively as human cognitive and vascular benefits overstates the existing preliminary animal and in vitro literature.

0:23:26needs contextvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Feeding Lactobacillus reuteri as a probiotic doubled the rate of wound healing in a study by prompting VEGF gene expression and blood vessel growth.

"So we actually did a research study where we were actually looking at whether or not feeding Lactobacillus reuteri as a probiotic would speed up wound healing. And indeed it doubled the rate of wound healing, and it did it from the gut by increasing the gene expression, turning on the genetic machinery for a protein called vascular endothelial growth factor, VEGF, just to prompt new blood vessels to grow just to be able to heal the wound." (said at 0:23:26)

In a controlled animal study in mice (PMID 24205344), oral administration of Lactobacillus reuteri in drinking water accelerated skin wound closure to occur in half the time of control animals (effectively doubling the rate of wound healing). The mechanism was shown to involve vagus nerve signaling, neuropeptide oxytocin up-regulation, and enhanced immune regulatory T-cell responses. Evidence is currently limited to preclinical rodent models, meaning translation to clinical wound healing rates in humans remains unestablished.

0:24:58supportedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Pulverized, non-viable Lactobacillus reuteri administered in drinking water to animals stimulates the brain to release oxytocin.

"So think about like a naval weapon, the sound weapon, and you can beam it at the Lactobacillus reuteri, pulverize it into a gajillion pieces. All right? You feed it to an experimental system to animals, putting it in their drinking water. And guess what? The dead pulverized bacteria will also make the brain release oxytocin." (said at 0:24:58)

Animal research supports the claim. In mouse models, oral dietary administration of a sterile lysate (non-viable, broken-down preparation) of Lactobacillus reuteri significantly increased oxytocin-producing cells in the paraventricular nucleus (PVN) of the hypothalamus and raised systemic oxytocin levels, demonstrating that bacterial viability is not required for oxytocin upregulation. Because evidence is limited to animal models, certainty is very low.

0:36:53supportedlowYour Diet Is Secretly Destroying Your Mental Health (Science

Research shows chimpanzees instinctively select and chew specific polyphenol-rich plants to heal wounds when injured.

"I don't know if you saw the research that looked at chimpanzees knowing inherently when they're injured that they'll pick specific plants to chew on them that will give them the bioactives of polyphenols from certain plants in order to be able to heal their wounds." (said at 0:36:53)

Observational research in wild chimpanzees (and other great apes) supports the claim that injured individuals selectively consume or process specific plants with potent bioactive properties to aid healing. A 2024 zoopharmacognosy study in the Budongo Forest documented injured chimpanzees seeking out and consuming rarely eaten plant species, such as the fern Christella parasitica and Khaya anthotheca bark/resin. In vitro pharmacological assays showed these specific extracts had potent anti-inflammatory (COX-2 inhibition) and antibacterial activities. Similar behavior was also documented in 2024 in a wild Sumatran orangutan, which chewed a medicinal liana (Fibraurea tinctoria) and applied its bioactive-rich juice directly to a facial wound. Certainty is rated as low due to the observational nature of field ethology combined with in vitro screening.

0:37:59supportedmoderateYour Diet Is Secretly Destroying Your Mental Health (Science

Brain inflammation is a common biological denominator observed across conditions such as schizophrenia, autism, major depression, and bipolar disorder.

"regardless of what mental health condition that you're talking about, everything from schizophrenia to autism to major depression, bipolar disorder, you know, so far what's been looked at as a common denominator of these syndromes is actually inflammation in the brain." (said at 0:37:59)

Published cross-disorder transcriptomic and neuroimaging research supports the statement that brain inflammation and neuroimmune dysregulation act as common, transdiagnostic features across major psychiatric and neurodevelopmental conditions, including schizophrenia, autism spectrum disorder, major depressive disorder, and bipolar disorder. Large-scale postmortem human brain transcriptome analyses demonstrate shared expression changes in innate immune-related genes across these four conditions. Furthermore, molecular neuroimaging and clinical reviews identify glial cell immune alterations and neuroinflammatory markers as shared pathophysiological denominators across these diagnoses.

0:39:30supportedhighYour Diet Is Secretly Destroying Your Mental Health (Science

Polyphenols found in fruits and vegetables lower biological inflammation.

"all those polyphenols and fruits and vegetables that you would eat can actually lower inflammation." (said at 0:39:30)

Multiple systematic reviews and meta-analyses of randomized controlled trials demonstrate that dietary polyphenols—such as those found in fruits, vegetables, and botanical sources—significantly reduce circulating biomarkers of inflammation, including C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α).

0:39:45supportedhighYour Diet Is Secretly Destroying Your Mental Health (Science

Psychological stress causes physical inflammation in the body.

"Stress causes inflammation. Most of us have a little bit more stress than we want in our lives. And so we're always a little bit inflamed" (said at 0:39:45)

Extensive meta-analytic evidence from experimental human laboratory studies demonstrates that acute psychological stress induces rapid, significant increases in circulating pro-inflammatory cytokines, including interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α). Furthermore, randomized controlled trials show that reducing psychological distress through psychological interventions significantly reduces systemic inflammatory markers such as C-reactive protein.

0:46:34unverifiedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Cantaloupe contains a natural polyphenol called atolavone, and melon aroma/flavor has anxiolytic effects that reduce anxiety.

"Atolavone actually is a natural polyphenol substance that's found in cantaloupe... And that actually lowers anxiety. So a melon flavor has been shown to lower the state of anxiety." (said at 0:46:34)

No published record matching the claim that cantaloupe contains a polyphenol called "atolavone" or that melon aroma/flavor has proven anxiolytic effects to reduce anxiety was located; this does not prove the claim false.

0:47:14overstatedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Dark chocolate contains anandamide, which activates the brain's endocannabinoid system.

"cacao has all these polyphenols in it, like proanthocyanidins and others, including anandamide. All right. And what do anandamides do when you eat them? They not only lower inflammation, but they stimulate the endocannabinoid system in your brain." (said at 0:47:14)

Cocoa and chocolate contain trace amounts of anandamide and related N-acylethanolamines that act as lipid cannabinoid mimics or inhibitors of anandamide breakdown. However, claiming that eating anandamide in dark chocolate stimulates the endocannabinoid system in the brain overstates the evidence: orally ingested lipid amides are rapidly metabolized in the gastrointestinal tract and liver, and there is no strong evidence that dietary trace quantities cross the blood-brain barrier to directly activate central cannabinoid receptors. Furthermore, anandamide is an N-acylethanolamine lipid rather than a polyphenol.

0:48:55supportedhighYour Diet Is Secretly Destroying Your Mental Health (Science

Truffles contain anandamide.

"Anandamide in truffles and chocolate." (said at 0:48:55)

Black truffles (specifically Tuber melanosporum) have been confirmed to contain the endocannabinoid anandamide (N-arachidonoylethanolamine) alongside its key metabolic synthesis and degradation enzymes. Liquid chromatography-mass spectrometry (LC-MS) analyses confirmed the presence and accumulation of anandamide across different maturation stages of the truffle fruiting bodies.

0:55:02overstatedvery lowYour Diet Is Secretly Destroying Your Mental Health (Science

Barley contains beta-glucan, a dietary fiber that stimulates blood vessel growth (angiogenesis) and nerve growth.

"Barley can also be beneficial. Barley has beta-glucan which is also found in mushrooms, culinary mushrooms as well as medicinal mushrooms. It's a kind of dietary fiber. They grow blood vessels and it can stimulate nerve growth as well." (said at 0:55:02)

The claim that barley contains beta-glucan which stimulates blood vessel growth (angiogenesis) and nerve growth overstates the available scientific evidence. Preclinical in vitro and animal research demonstrates that barley-derived (1,3)-β-D-glucan can stimulate angiogenic responses and vascular formation under oxidative stress conditions in endothelial cells (HUVECs) and zebrafish embryos (PMID: 25388628). However, this effect has been demonstrated only in cell and animal models using isolated purified extracts, not human dietary consumption of barley. Furthermore, evidence direct to barley beta-glucan stimulating nerve growth in humans or animal models is lacking in published literature.

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