HoldsUp

DavidPerlmutterMD · 2017-11-12 · David Perlmutter (host), Daniel Amen

Proven Strategies to Prevent Disease - with Dr. Daniel Amen | The Empowering Neurologist EP. 55

51 research-tied claims examined: 1 contradicted 7 overstated 6 context 30 supported 7 unverified

1

Contradicted by research

0:08:25Daniel Amencontradictedhigh

Low cerebral blood flow, particularly in the hippocampus, parietal lobes, and posterior cingulate gyrus, is the primary brain imaging predictor of Alzheimer's disease.

"The number one brain imaging predictor of Alzheimer's disease is low blood flow, especially in the hippocampus and in the back half of your brain, the parietal lobes, and an area called the posterior cingulate gyrus." (said at 0:08:25)

While hypoperfusion and hypometabolism in the posterior cingulate cortex, parietal lobes, and hippocampus are well-recognized neurodegenerative patterns in Alzheimer's disease (AD), low cerebral blood flow is not the primary or "number one" neuroimaging predictor of AD. Under the established National Institute on Aging and Alzheimer's Association (NIA-AA) diagnostic and research frameworks, the primary Core-1 and Core-2 diagnostic imaging biomarkers for Alzheimer's disease are amyloid-beta PET and tau PET. Functional imaging measures such as regional perfusion or FDG-PET metabolism reflect downstream neurodegeneration ('N') or vascular changes ('V') rather than the primary disease-defining biomarkers.

  • context: Glucose metabolism in posterior cingulate cortex has supplementary value to predict the pr… (GeroScience 2024) · cited 13x in the literature
    "Amyloid-β (Aβ) and tau are important biomarkers to predict the progression of cognitively unimpaired (CU) to dementia due to Alzheimer's disease (AD), according to the diagnosis framework from the US National Institute on Aging and the Alzheimer's Association (NIA-AA)... As a typical characteristic of neurodegeneration in the diagnosis framework, the hypometabolism of the posterior cingulate cortex (PCC) has significant clinical value in the early prediction and prevention of AD. In this paper, we proposed the glucose metabolism in the PCC as a biomarker supplement to Aβ and tau biomarkers." (abstract, results, passage verified)
    pubmedfull study (doi)
  • contradicts: The 2024 NIA-AA biological definition of Alzheimer's disease: linking biomarkers to clinic… (Frontiers in dementia 2026) · cited 11x in the literature
    "The 2024 framework defines AD by its underlying pathology rather than clinical symptoms, recognizing that biomarker evidence alone can establish diagnosis. It expands the traditional AT (N) model into a multimodal profile (AT 1 T 2 NISV), in which Core-1 biomarkers (A and T 1 ) are diagnostic, while Core-2 biomarkers (T 2 ) support biological staging. Non-specific but mechanistically important processes (N, neurodegeneration; I, inflammation) and common co-pathologies (S, α -synuclein; V, vascular injury) are also incorporated" (abstract, results, passage verified)
    pubmedfull study (doi)
7

Overstated

0:18:54Daniel Amenoverstatedlow

A study by Joseph Hibbeln at the NIH found that vegetarians experience a high incidence of depression due in part to low omega-3 fatty acids.

"Brand new study out yesterday from Joe Hibbeln from NIH: vegetarians have a high incidence of depression. And when he was writing about why, part of it was low omega-3 fatty acids." (said at 0:18:54)

A study led by Joseph R. Hibbeln analyzed data from 9,668 male partners of pregnant women in the Avon Longitudinal Study of Parents and Children (ALSPAC) and found that self-identified vegetarian men had higher depression scores and increased odds of significant depressive symptoms (adjusted OR 1.67, 95% CI 1.14–2.44) compared to non-vegetarians (PMID 28777971). However, stating that the study proved vegetarian diets cause depression due to low omega-3 fatty acids overstates the findings. The study was observational, meaning it could not prove causality, and the authors explicitly noted that reverse causation could not be ruled out. Furthermore, the abstract lists potential nutritional deficiency explanations such as cobalamin (vitamin B12) or iron rather than establishing omega-3 deficiency as the definitive cause.

0:25:40Daniel Amenoverstatedvery low

Curcumin combined with vitamin D decreases amyloid plaques associated with Alzheimer's disease.

"It's also, when combined with vitamin D, been shown to decrease the plaques thought to be involved in Alzheimer's disease." (said at 0:25:40)

The claim is based on preliminary in vitro (cell culture) laboratory experiments rather than clinical trials in humans. In laboratory studies using macrophages isolated from Alzheimer's disease patients, combining 1α,25-dihydroxyvitamin D3 with curcuminoids enhanced the uptake (phagocytosis) and clearance of amyloid-beta in a subset of patient samples (termed Type I macrophages). However, there is no clinical trial evidence demonstrating that curcumin and vitamin D supplementation reduces brain amyloid plaque burden or improves clinical outcomes in Alzheimer's disease patients.

0:05:46David Perlmutter (host)overstatedmoderate

By age 85, approximately 50% of individuals will be diagnosed with Alzheimer's disease.

"when you look at the statistic that shows at age 85 that 50% of people will be diagnosed, you know, I think we should all assume that if we avoid other issues, other diseases or trauma, there's at least the flip of a coin chance that we're going to end up as an Alzheimer's patient." (said at 0:05:46)

Large-scale epidemiological studies and national prevalence models indicate that the proportion of individuals aged 85 and older living with Alzheimer's dementia is approximately one-third (around 32% to 35%), rather than 50%. While early community studies in the late 1980s reported rates approaching 47% in the oldest age bracket, contemporary population-based data show that at age 85, the majority of older adults do not have Alzheimer's disease.

0:41:45Daniel Amenoverstatedlow

Untreated depression doubles the risk of Alzheimer's disease in women and quadruples the risk in men.

"if you have untreated depression, in women it doubles your risk for Alzheimer's disease, in men it quadruples the risk." (said at 0:41:45)

The claim that untreated depression doubles Alzheimer's risk in women and quadruples it in men is overstated and contradicted by large pooled meta-analytic data. While observational studies have long established an association between late-life depressive symptoms and incident dementia or Alzheimer's disease (and some individual cohort studies, such as the PAQUID study, reported elevated dementia risk in men with proximal depressive symptoms but weaker associations in women), systematic multi-cohort investigations find no established, consistent 2-fold (women) versus 4-fold (men) dichotomy. In particular, a large individual-participant data meta-analysis from the COSMIC consortium (29,850 participants across 21 cohorts) found no discernible sex difference in the association between depression and dementia risk, showing that most major risk factors operate similarly in both sexes.

0:43:03Daniel Amenoverstatedvery low

Omega-3 fatty acids are equally effective as antidepressants in head-to-head comparisons for depression.

"Head-to-head against antidepressants, omega-3 fatty acids, equally effective for depression." (said at 0:43:03)

Direct head-to-head evidence comparing omega-3 fatty acids to standard antidepressants is extremely limited. A single small 8-week randomized trial of 60 outpatients (Jazayeri et al., 2008) observed similar reductions in depression scores between 1,000 mg/day of eicosapentaenoic acid (EPA) and 20 mg/day of fluoxetine. However, Cochrane systematic reviews evaluating omega-3 fatty acids for major depressive disorder identify only this single trial (40 evaluable participants) with very low-certainty evidence, concluding that evidence is insufficient to establish comparative equivalence. Furthermore, broader meta-analyses find that omega-3 fatty acids produce only a small, unlikely to be clinically meaningful benefit over placebo with substantial risk of bias.

0:44:36Daniel Amenoverstatedmoderate

Two studies from the Netherlands found that putting children with ADHD on an elimination diet resulted in 70% losing their symptoms.

"So there's two studies from Holland. When they put ADHD kids on an elimination diet, 70% of them lost their symptoms." (said at 0:44:36)

Two Dutch randomized trials led by Pelsser and colleagues (a 2009 pilot trial and the 2011 INCA trial published in The Lancet) evaluated a supervised few-foods restricted elimination diet in children with ADHD. The 2009 trial reported that 70% (by teacher ratings) to 73% (by parent ratings) of children in the diet group were clinical responders, defined as a ≥50% decrease in ADHD symptom scores. The 2011 INCA trial similarly found substantial improvements (defined as ≥40% improvement on the ADHD Rating Scale) in about 64% of participants. Describing this as 70% 'losing their symptoms' is overstated, as the trials measured significant symptom score reductions rather than full symptom remission or cure.

0:49:44Daniel Amenoverstatedvery low

The geographic areas with the highest incidence of schizophrenia in the United States directly overlap with the highest incidence of Lyme disease.

"But if you look at a map of the United States and you look at the highest incidence of schizophrenia, it's going to show the Northeast, Michigan, and Illinois, and then the West Coast. And then if you overlay on the highest incidence of schizophrenia in the US the highest incidence of Lyme disease, they're exactly the same." (said at 0:49:44)

An ecological study published in 1994 examined US geographic patterns and observed that areas with higher reported schizophrenia rates (urbanized Northeastern, Northwestern, and Great Lakes states) showed a statistically significant regional correlation with the distribution of Lyme disease foci and Ixodid ticks. However, claiming the geographical maps are "exactly the same" overstates broad regional ecological correlations, which are prone to confounding (such as urbanization and diagnostic access) and do not establish an exact spatial match or individual-level causal link.

6

Needs context

0:07:00Daniel Amenneeds contextlow

Adult humans produce approximately 700 new hippocampal stem cells each day.

"And in one study I read, you actually make 700 new stem cells, hippocampal stem cells, every day." (said at 0:07:00)

The speaker is referencing a landmark 2013 study by Spalding and colleagues (Cell), which used carbon-14 dating from nuclear bomb testing to estimate that approximately 700 new neurons (not stem cells) are added in each hippocampus per day in adult humans, corresponding to an annual turnover rate of 1.75% within the renewing neuronal population. However, this estimate refers to newly generated neurons rather than stem cells, and the broader scientific community remains divided regarding the extent of adult human hippocampal neurogenesis, with subsequent postmortem studies (e.g., Sorrells et al., Nature 2018) finding that neurogenesis drops to undetectable or extremely rare levels in adulthood.

0:09:35Daniel Amenneeds contextmoderate

A study from Harvard found that 40% of 40-year-olds and 70% of 70-year-olds have erectile dysfunction.

"And I read one study from Harvard that said 40% of 40-year-olds have erectile dysfunction and 70% of 70-year-olds." (said at 0:09:35)

This commonly cited rule of thumb originates from the Massachusetts Male Aging Study (MMAS), a landmark population-based study conducted near Boston in men aged 40 to 70. The study found that total erectile dysfunction (combining minimal, moderate, and complete impotence) was present in approximately 40% of men at age 40 and approximately 70% of men at age 70 (overall combined prevalence of 52%). However, most cases in younger cohorts represent mild or minimal dysfunction; severe or complete erectile dysfunction occurred in only about 5% of 40-year-olds and 15% of 70-year-olds.

  • context: Impotence and its medical and psychosocial correlates: results of the Massachusetts Male A… (The Journal of urology 1994) · cited 5122x in the literature
    "The Massachusetts Male Aging Study was a community based, random sample observational survey of noninstitutionalized men 40 to 70 years old conducted from 1987 to 1989 in cities and towns near Boston, Massachusetts. Blood samples, physiological measures, socio-demographic variables, psychological indexes, and information on health status, medications, smoking and lifestyle were collected by trained interviewers in the subject's home. A self-administered sexual activity questionnaire was used to characterize erectile potency. The combined prevalence of minimal, moderate and complete impotence was 52%. The prevalence of complete impotence tripled from 5 to 15% between subject ages 40 and 70 years." (abstract, results, passage verified)
    pubmedfull study (doi)
0:32:48Daniel Amenneeds contextlow

Ninety-four percent of traumatic brain injuries affect the frontal lobes.

"so of traumatic brain injuries, 94% of them affect the frontal lobes" (said at 0:32:48)

The speaker claims that 94% of traumatic brain injuries (TBIs) affect the frontal lobes. This statistic originates from a systematic review evaluating the clinical utility of single-photon emission computed tomography (SPECT) in TBI (Raji et al., 2014). The systematic review found that across cross-sectional brain SPECT imaging studies of TBI patients, the frontal lobes were the most common region showing neuroimaging abnormalities (94% of cross-sectional studies reported frontal lobe abnormalities, and 77% reported temporal lobe abnormalities). However, stating that 94% of all traumatic brain injuries affect the frontal lobes misrepresents what the statistic actually measures. The 94% figure refers to the proportion of cross-sectional SPECT studies in a systematic review that identified frontal lobe perfusion abnormalities among evaluated TBI patients, not a epidemiological population measure that 94% of all clinical TBI incidents involve frontal lobe injury.

0:35:33Daniel Amenneeds contextmoderate

Undergoing coronary artery bypass surgery increases the risk of cognitive impairment and Alzheimer's disease.

"and for example, if you have coronary artery bypass surgery, that increases your risk of having cognitive impairment and Alzheimer's disease." (said at 0:35:33)

The claim that coronary artery bypass graft (CABG) surgery increases the risk of cognitive impairment and Alzheimer's disease requires important qualification. Postoperative cognitive decline and short-term cognitive impairment are common following CABG surgery, with meta-analyses reporting acute cognitive impairment in roughly 35% to 43% of patients post-CABG. However, evidence on whether CABG independently increases the long-term risk of Alzheimer's disease compared to non-surgical cardiovascular disease remains mixed. While some population studies show an elevated hazard ratio for dementia and Alzheimer's disease in patients with a history of CABG, large national registry studies show no overall increase in all-cause dementia risk compared to matched controls, and controlled longitudinal studies suggest cognitive trajectories in these patients are primarily driven by underlying vascular disease and cardiovascular risk factors rather than the surgery itself.

0:39:16Daniel Amenneeds contextlow

A long-term longevity study found that conscientiousness was the primary personality predictor of longevity, while highly cheerful or unworried individuals died earlier from accidents or preventable illnesses.

"So you might know the longevity study, the one from Harvard where they look at people over 90 years, the number one predictor of longevity was not happiness or a lack of worry—"Don't worry, be happy" people died the earliest from accidents or preventable illnesses, so I always wanted to be one of those people, I'm not—that the number one predictor was conscientiousness." (said at 0:39:16)

The speaker accurately describes the core findings of a landmark multi-decade lifespan study, although the research referenced is the Terman Life Cycle Study (analyzed extensively by Howard S. Friedman and colleagues, often called The Longevity Project out of Stanford/UC Riverside), rather than the Harvard Study of Adult Development. In analyses following participants from childhood across seven to eight decades, childhood conscientiousness emerged as the strongest personality predictor of longevity, whereas cheerfulness and high optimism were unexpectedly associated with reduced longevity, partly due to increased engagement in health-risk behaviors and preventable mortality. Meta-analyses have further confirmed the positive relationship between conscientiousness and survival.

0:43:43David Perlmutter (host)needs contexthigh

Approximately 6.5 million American children have an ADHD diagnosis, with about two-thirds receiving medication.

"the statistic is that about 6.5 million American children carry a diagnosis of ADHD and about two-thirds of them are medicated, most of whom are medicated with stimulants and basically amphetamines." (said at 0:43:43)

The speaker's statement combines statistics from different survey cycles of the U.S. National Survey of Children's Health (NSCH). According to 2022 NSCH data published by CDC researchers, an estimated 6.5 million U.S. children aged 3–17 years currently have an ADHD diagnosis (10.5%). However, in that same 2022 survey, 53.6% (approximately half) of children with current ADHD were receiving medication. The "about two-thirds" figure corresponds to earlier NSCH data cycles, such as 2016 (where 62.0% were taking medication) and 2011 (where 69% were taking medication).

30

Supported by research

0:08:55Daniel Amensupportedmoderate

Pre-hypertension is associated with brain atrophy.

"Even being pre-hypertensive is associated with brain atrophy." (said at 0:08:55)

Observational neuroimaging research shows that prehypertensive or elevated blood pressure (defined as systolic blood pressure of 120–139 mm Hg or diastolic blood pressure of 80–89 mm Hg) is associated with reduced regional gray matter volume and lower total cerebral brain volume, even in young to middle-aged adults without clinical hypertension.

0:12:25Daniel Amensupportedvery low

Hyperbaric oxygen therapy significantly improves cerebral blood flow in military personnel who suffered blast injuries.

"I published a study in the Journal of Neurotrauma on soldiers who had blast injuries: significant improvements in blood flow with hyperbaric oxygen." (said at 0:12:25)

A preliminary phase I clinical trial published in the Journal of Neurotrauma evaluated 16 military personnel with blast-induced mild-to-moderate traumatic brain injury/post-concussion syndrome and post-traumatic stress disorder treated with 40 sessions of 1.5 ATA hyperbaric oxygen therapy (HBOT). Single-photon emission computed tomography (SPECT) statistical parametric mapping analysis showed diffuse, statistically significant improvements in regional cerebral blood flow after 1 and 40 sessions. However, the evidence certainty is very low because the study was a small, open-label, uncontrolled pilot trial without a sham control group.

0:12:38Daniel Amensupportedmoderate

Meditation increases blood flow and neural activity in the frontal lobes.

"And meditation, which actually fooled us because, you know, you'd think meditation, it would calm everything down in the brain. Absolutely doesn't do that, especially in your frontal lobes; it increases blood flow and activity." (said at 0:12:38)

Functional neuroimaging and cerebral blood flow (CBF) studies demonstrate that meditation engages and increases neural activation and blood flow in frontal lobe regions, particularly the prefrontal cortex and anterior cingulate, rather than inducing generalized cerebral deactivation. Single photon emission computed tomography (SPECT) studies show significant increases in regional cerebral blood flow in the dorsolateral prefrontal cortex, orbital frontal cortex, and cingulate gyrus during meditation, as well as higher baseline prefrontal CBF in experienced meditators. Coordinate-based fMRI meta-analyses similarly confirm consistent activation of fronto-medial and prefrontal networks during meditative practices, reflecting active attentional and executive control processes.

0:12:58Daniel Amensupportedmoderate

Brain SPECT imaging studies demonstrate that Ginkgo biloba and vinpocetine increase cerebral blood flow.

"And from a supplement standpoint, I'm a huge fan of Ginkgo and vinpocetine. Brain SPECT imaging studies on both of them showing that they increase blood flow." (said at 0:12:58)

Published neuroimaging studies using single photon emission computed tomography (SPECT) have documented increases in regional cerebral blood flow or perfusion following administration of Ginkgo biloba and vinpocetine. A double-blind, randomized trial of Ginkgo biloba in older men found improved cerebral perfusion on SPECT alongside reduced blood viscosity. Similarly, clinical investigations and reviews evaluating vinpocetine (Cavinton) in patients with chronic cerebrovascular insufficiency report enhanced cerebral hemoperfusion and metabolism measured via SPECT and related imaging modalities.

0:13:28Daniel Amensupportedlow

A UK study of 88,000 people found that individuals playing racquet sports had increased longevity compared to other sports participants, whereas running showed no mortality difference.

"But there was a study last year on 88,000 people in the United Kingdom: the people who played racquet sports lived longer than everyone else. So football players lived shorter than everyone else, soccer players shorter, runners actually didn't make a difference, swimmers longer, but it was tennis, table tennis, badminton, squash, racquetball that they lived longer." (said at 0:13:28)

A 2017 pooled cohort study of 80,306 British adults published in the British Journal of Sports Medicine examined the associations of six sport types with mortality. Participation in racquet sports (badminton, tennis, squash) had the strongest inverse association with all-cause mortality (hazard ratio 0.53, 95% CI 0.40 to 0.69) compared to non-participation, followed by swimming, aerobics, and cycling. In contrast, participation in running/jogging and football showed no statistically significant reduction in all-cause or cardiovascular mortality after multivariable adjustment. Note that while football players did not show a survival advantage in this cohort, they did not have a statistically significant increase in mortality ('lived shorter'). As an observational study, residual confounding and reverse causation cannot be ruled out.

0:14:10Daniel Amensupportedmoderate

Damage to the left frontal lobe turns off or suppresses activity in the right cerebellum due to cross-cerebellar diaschisis.

"If you damage the left frontal lobe, it actually turns off your right cerebellum, and we can see it beautifully on SPECT." (said at 0:14:10)

The speaker accurately describes crossed cerebellar diaschisis (CCD), a well-characterized neuroanatomical phenomenon in which supratentorial injury (such as ischemic damage or lesions in the frontal or motor cortex) leads to a functional depression of blood flow and metabolism in the contralateral cerebellar hemisphere via disruption of the cortico-ponto-cerebellar pathway. This reduction in contralateral cerebellar perfusion and metabolism is routinely detected and visualized using single-photon emission computed tomography (SPECT) as well as PET imaging.

0:14:40David Perlmutter (host)supportedhigh

A study by Erickson and colleagues showed that one year of aerobic exercise increased hippocampal volume, whereas stretching exercise led to a decline in hippocampal volume.

"You know, there's a graph that I use in some of my talks by Dr. Erickson and his group, collaborative study UCLA and University of Pittsburgh, looking at size, basically just the size of the hippocampus, the memory center, if you will, over a one-year period in people who get some form of aerobic exercise versus those who simply stretch. The stretch people, their hippocampus, as you would expect, declined in size, whereas those who were aerobically exercising, their hippocampus increased in size." (said at 0:14:40)

The speaker accurately describes the findings of the randomized controlled trial by Erickson et al. (2011) involving 120 older adults. In that study, participants were randomized to a 1-year moderate-intensity aerobic exercise regimen or a stretching/toning control group. Aerobic exercise increased hippocampal volume by approximately 2% (effectively reversing age-related volume loss by 1 to 2 years), whereas the stretching control group showed a decline in hippocampal volume over the 1-year period.

0:16:44Daniel Amensupportedmoderate

A study conducted in Baltimore found that volunteering increased hippocampal volume in older adults.

"And there's a study from Baltimore that found volunteering actually increased the size of the hippocampus." (said at 0:16:44)

A randomized controlled trial nested within the Baltimore Experience Corps Trial (an intergenerational volunteering program for older adults in public elementary schools) evaluated changes in brain volume over 2 years in 111 older adults. Participants in the volunteering arm demonstrated increases in cortical and hippocampal volumes compared to the typical age-related volume loss observed in control participants; these increases reached statistical significance in men (0.7% to 1.6% increase) and showed modest gains (0.3% to 0.54%) relative to control declines in women.

0:18:21Daniel Amensupportedmoderate

Elevated C-reactive protein levels correlate with a higher incidence of depression.

"So very few people actually know that, but in the studies looking at C-reactive protein, there is a higher incidence of depression in people who have high C-reactive protein." (said at 0:18:21)

Prospective longitudinal studies and meta-analyses support the association between elevated baseline C-reactive protein (CRP) levels and a higher subsequent risk or incidence of depressive symptoms. A systematic review and meta-analysis of prospective community studies (PMID: 32807846) confirmed that baseline CRP elevation is associated with future depressive symptoms in both unadjusted and adjusted analyses, although the effect size is modest and significantly attenuated after controlling for confounding factors (such as BMI, health status, and age).

0:18:54Daniel Amensupportedmoderate

A lower omega-3 index is associated with an increased risk of depression.

"Also, people who have a low omega-3 index, which is a study helped to be designed by Bill Harris from OmegaQuant—I think he's at the University of South Dakota. The lower your omega-3 index, the higher your risk for depression." (said at 0:18:54)

The claim accurately reflects epidemiological and clinical evidence linking a lower omega-3 index (the sum of eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA] in red blood cell membranes) with an increased risk or severity of depressive symptoms. Multiple observational, case-control, and cohort studies demonstrate that lower red blood cell omega-3 fatty acid levels are inversely correlated with depression severity and major depressive disorder. For example, acute coronary syndrome patients with low omega-3 index values exhibit higher depressive symptom scores (PMID: 18842751), lower omega-3 index levels during pregnancy predict higher postpartum depressive symptoms (PMID: 23844041), and depressed adolescents show a significantly reduced omega-3 index compared to controls (PMID: 22464051). Systematic review evidence synthesising psychiatric research also identifies low omega-3 index status as a significant risk factor across major depressive disorder and postpartum depression (PMID: 37575565). Because the underlying data primarily stem from observational and case-control studies subject to potential residual confounding, the certainty of evidence for a causal risk relationship is moderate.

0:22:35David Perlmutter (host)supportedmoderate

A study published in JAMA showed a dramatic increase in urinary glyphosate excretion in humans over recent years.

"Well, there was a study that came out last week in the Journal of the American Medical Association and indicated a dramatic increase in excretion of glyphosate metabolites in measuring urinary samples from a few years ago to those from quite recently." (said at 0:22:35)

A 2017 research letter published in JAMA (Mills et al.) examined urinary excretion of glyphosate and its primary metabolite, aminomethylphosphonic acid (AMPA), in older adults participating in the Rancho Bernardo Study of Healthy Aging. The investigators compared samples collected between 1993–1996 and 2014–2016, finding substantial increases over time in both the proportion of individuals with detectable urinary levels (increasing from 12% to 70%) and the mean excretion concentrations.

0:27:20Daniel Amensupportedhigh

For psychiatric conditions like ADHD and depression, EPA is the beneficial omega-3 fatty acid, while DHA is ineffective.

"And people think of EPA for the heart and DHA for the brain, but I don't like people thinking like that, because people who have ADHD or depression, DHA is not helpful at all; it's EPA that seems to be the most helpful." (said at 0:27:20)

Multiple meta-analyses of randomized controlled trials confirm that eicosapentaenoic acid (EPA), rather than docosahexaenoic acid (DHA), is the primary driver of clinical efficacy in both depression and ADHD. In major depressive disorder, EPA-predominant formulations (typically containing ≥60% EPA) consistently show significant antidepressant benefits over placebo, whereas DHA-pure or DHA-predominant formulas fail to demonstrate efficacy. Similarly, meta-analytic evidence in ADHD indicates that symptom improvement with omega-3 supplementation is specifically correlated with higher EPA doses rather than DHA.

0:16:09Daniel Amensupportedmoderate

Working in an occupation that does not require new learning is associated with an increased risk of memory problems.

"If you're in a job that does not require new learning, you actually have a higher risk of memory problems." (said at 0:16:09)

Large prospective cohort studies demonstrate that occupations with low cognitive stimulation and low demand for novel, non-routine tasks are associated with an increased risk of subsequent cognitive impairment and dementia. In the HUNT4 70+ longitudinal cohort (n = 7,003), individuals working in jobs characterized by high routine task intensity (and low cognitive demands) during midlife had a significantly higher risk of developing mild cognitive impairment (relative risk ratio 1.74, 95% CI 1.41–2.14) and dementia (RRR 1.37, 95% CI 1.01–1.86) compared to those in cognitively demanding roles. Similarly, an individual-participant meta-analysis of over 107,000 adults across Europe and the US found that individuals in low cognitive stimulation jobs had a significantly higher risk of dementia compared to those with high cognitive stimulation at work (adjusted HR 0.82 for high stimulation, 95% CI 0.68–0.98).

0:30:49David Perlmutter (host)supportedlow

A study in an indigenous Bolivian tribe found that the APOE-e4 allele was protective against cognitive decline in individuals with high parasite burdens.

"there was a recent study that came out that demonstrated, in an indigenous tribe living in Bolivia, that the E4 gene was protective of cognitive function in those individuals who had the highest eosinophil count, i.e. the highest level of parasites." (said at 0:30:49)

A 2017 observational study of 372 Tsimane forager-horticulturalists in the Bolivian Amazon found that apolipoprotein E4 (APOE-e4) carriers with high parasite/pathogen burdens maintained or had slightly better cognitive performance compared to non-carriers with high parasite burdens, who exhibited poorer cognitive performance. As this is an observational cohort study, the overall GRADE certainty of the body of evidence is low.

0:31:28David Perlmutter (host)supportedmoderate

Approximately 20% of human populations carry the APOE-e4 allele.

"Why do we still see 20% of populations carrying this allele?" (said at 0:31:28)

Population genetics and epidemiological studies consistently establish that the APOE ε4 allele is present globally, with approximately 15% to 25% of individuals carrying at least one copy of the ε4 allele across various human populations (and higher frequencies in specific indigenous and equatorial groups). Evolutionary medicine research demonstrates that despite its association with increased risks for Alzheimer's disease and cardiovascular disease in modern industrialized settings, the allele has been maintained at substantial frequencies worldwide, potentially conferring selective advantages such as resilience against infectious pathogens and high parasite burdens.

0:33:31Daniel Amensupportedvery low

Eighty percent of retired NFL players treated with Dr. Amen's intervention program demonstrated cognitive improvement.

"This is what we used on our NFL players, and 80% of our players—we published this—80% of our players show improvement when we put them on this program" (said at 0:33:31)

The speaker accurately cites the findings from their published open-label clinical trial in 30 retired NFL players. In the study, retired players underwent an average of 6 months on a multi-component intervention (lifestyle changes, fish oil, and brain-directed dietary supplements) and demonstrated significant improvements across multiple cognitive domains on the MicroCog assessment (corrected for practice effects) and increased cerebral perfusion on brain SPECT. Because the study was a small, open-label, uncontrolled before-and-after case series, the certainty of evidence for the intervention's causal efficacy is very low.

0:38:12Daniel Amensupportedlow

A Finnish study found that taking saunas five to seven times a week was associated with a two-thirds lower risk of Alzheimer's disease compared to taking them once a week or not at all.

"Brand new study from Finland: people who take saunas five to seven times a week had two-thirds lower risk of Alzheimer's disease than people who were just taking it once a week or not taking them at all." (said at 0:38:12)

A prospective cohort study of 2,315 middle-aged Finnish men (the Kuopio Ischaemic Heart Disease study) followed for over 20 years found that men who took saunas 4 to 7 times per week had a 65% lower risk of Alzheimer's disease (hazard ratio 0.35, 95% CI: 0.14-0.90) and a 66% lower risk of dementia (hazard ratio 0.34, 95% CI: 0.16-0.71) compared to men who had only 1 sauna session per week. As this is observational cohort data in a male-only Finnish population, evidence certainty is graded as low.

  • supports: Sauna bathing is inversely associated with dementia and Alzheimer's disease in middle-aged… (Age and ageing 2017) · cited 134x in the literature
    "In analysis adjusted for age, alcohol consumption, body mass index, systolic blood pressure, smoking status, Type 2 diabetes, previous myocardial infarction, resting heart rate and serum low-density lipoprotein cholesterol, compared with men with only 1 sauna bathing session per week, the HR for dementia was 0.78 (95% CI: 0.57-1.06) for 2-3 sauna bathing sessions per week and 0.34 (95% CI: 0.16-0.71) for 4-7 sauna bathing sessions per week. The corresponding HRs for Alzheimer's disease were 0.80 (95% CI: 0.53-1.20) and 0.35 (95% CI: 0.14-0.90)." (abstract, results, passage verified)
    pubmedfull study (doi)
0:42:57Daniel Amensupportedmoderate

Exercise is equally effective as antidepressants in head-to-head studies for depression.

"Head-to-head against antidepressants, exercise is equally effective for depression." (said at 0:42:57)

Systematic reviews and network meta-analyses of randomised controlled trials comparing exercise interventions directly against antidepressant medications (pharmacotherapy) find comparable reductions in depressive symptom severity, with no statistically significant differences in effectiveness between the two modalities for non-severe or major depression. However, study authors note that exercise interventions often suffer from higher dropout rates than pharmacological treatments and that many trials have methodological limitations such as lack of participant blinding.

0:43:08Daniel Amensupportedhigh

Cognitive restructuring techniques are equally effective as antidepressants head-to-head.

"Head-to-head against antidepressants, learning how to not believe every stupid thought you have is equally effective as antidepressants." (said at 0:43:08)

Large systematic reviews and meta-analyses of randomized controlled trials demonstrate that cognitive behavioral therapy (CBT), which centers on cognitive restructuring (identifying and modifying maladaptive or automatic negative thoughts), demonstrates comparable efficacy to antidepressant medications in the acute treatment of depression. Furthermore, CBT shows advantages over pharmacotherapy at longer-term follow-up (6 to 12 months) due to enduring skills and lower relapse rates.

0:45:45Daniel Amensupportedmoderate

A Harvard study found that 52% of individuals with untreated ADHD have substance abuse issues.

"52% according to one study from Harvard have problems with substance abuse" (said at 0:45:45)

A landmark longitudinal study from Harvard Medical School / Massachusetts General Hospital (Biederman et al., 1999) and related cohort studies from the same group evaluated substance use disorder (SUD) rates among individuals with ADHD. In longitudinal follow-ups and adult cohorts, untreated ADHD was associated with a marked increase in substance use disorders (with lifetime prevalence around 52% to 75% in untreated/clinical adult cohorts, compared to significantly lower rates in medicated individuals and controls).

0:49:20Daniel Amensupportedlow

Having asthma increases the risk of Alzheimer's disease by 20%.

"And autoimmune disorders increase your risk of Alzheimer's disease, even simple ones like asthma. If you have asthma, it increases your risk 20%." (said at 0:49:20)

Large observational studies support the claim that asthma is associated with an approximately 20% increase in the risk of Alzheimer's disease. A 2024 nationwide Medicare cohort study of over 5.4 million beneficiaries found that individuals with asthma had a 20% to 33% higher 2-year incidence of Alzheimer's disease (matched odds ratio 1.20, 95% CI 1.17–1.24). A 2025 meta-analysis similarly identified elevated risks of cognitive decline and dementia among asthma patients. Notably, these findings reflect observational associations rather than proven direct causation, and asthma is medically classified as a chronic inflammatory/allergic airway disease rather than a classic autoimmune disorder.

0:51:12David Perlmutter (host)supportedvery low

Dr. Rudolph Tanzi's research demonstrated that beta-amyloid plaque functions as an antimicrobial peptide in response to infection.

"The work of Dr. Rudolph Tanzi at Harvard—you know Rudy, I guess, pretty well—you know, really makes us understand that this plaque, amyloid plaque, is an antimicrobial peptide and is the response to infection" (said at 0:51:12)

Research led by Dr. Rudolph Tanzi and the late Dr. Robert Moir at Harvard demonstrated that amyloid-beta (Aβ) exhibits antimicrobial properties and can function as an antimicrobial peptide (AMP) within the innate immune system. In a series of in vitro, nematode, transgenic mouse (5XFAD), and cell culture studies, they showed that Aβ peptide possesses potent antimicrobial activity against bacteria, fungi, and herpesviruses (HSV-1 and HHV-6), with microbial exposure rapidly seeding and accelerating Aβ fibrillization to entrap pathogens. Because these findings are derived from cell cultures, animal infection models, and post-mortem brain tissue, certainty regarding the full clinical role of this mechanism in human Alzheimer's disease remains very low, but the statement accurately describes the findings of Dr. Tanzi's research.

0:53:28Daniel Amensupportedmoderate

Consuming a high dose of sugar causes an acute drop in testosterone levels of 25%.

"because if you get a sugar burst, it drops your testosterone by 25%." (said at 0:53:28)

Clinical studies show that acute ingestion of a glucose load causes a rapid, transient reduction in serum testosterone levels in men. In randomized experimental and crossover trials, acute oral glucose intake acutely suppresses total and basal testosterone secretion (typically by approximately 25%) in conjunction with reductions in pulsatile luteinizing hormone (LH) secretion.

0:53:46Daniel Amensupportedhigh

Forty percent of Americans are obese.

"a brand-new study just came out last week: 40% of Americans are obese." (said at 0:53:46)

Nationally representative surveillance data from the National Health and Nutrition Examination Survey (NHANES) published by the CDC's National Center for Health Statistics found that the prevalence of obesity (BMI ≥ 30) among US adults was 40.3% during the August 2021–August 2023 cycle.

0:53:58Daniel Amensupportedlow

A brain imaging study by Cyrus Raji showed that overweight individuals had 4% less brain volume and obese individuals had 8% less brain volume compared to normal-weight individuals.

"He published the first study—I call it the dinosaur syndrome. He showed as a person's weight went up, the actual physical size of their brain went down. If you were overweight, you had 4% less brain volume, and your brain looked eight years older than healthy people. If you were obese, you had 8% less volume, and your brain looked 16 years older than the healthy weight population." (said at 0:53:58)

A 2010 neuroimaging study led by Cyrus Raji evaluated 94 cognitively normal elderly participants and examined brain tissue volume differences using tensor-based morphometry. The investigators found that higher BMI was associated with regional and global brain volume deficits, showing that overweight individuals had approximately 4% lower brain volume (corresponding to roughly 8 years of accelerated brain aging) and obese individuals had approximately 8% lower brain volume (corresponding to roughly 16 years of accelerated brain aging) compared to normal-weight individuals. Because this was a cross-sectional observational study with a relatively small sample size, the overall certainty of the evidence is low.

0:55:34David Perlmutter (host)supportedlow

A study published in the Archives of Neurology found an inverse correlation between waist-to-hip ratio and hippocampal volume.

"There's a great study from JAMA many years ago—actually it was from the Archives of Neurology at the time—that correlated waist-to-hip ratio inversely with the size of your hippocampus: the bigger your belly, the smaller hippocampus." (said at 0:55:34)

A 2005 cross-sectional study published in the Archives of Neurology (Jagust et al.) examined 112 older participants from the Sacramento Area Latino Study on Aging and found that waist-to-hip ratio (WHR) was negatively correlated with hippocampal volume (P = .02). Specifically, each 1-standard-deviation increase in WHR was associated with a 0.2-standard-deviation decrease in hippocampal volume, even after adjusting for body mass index, blood pressure, and metabolic markers.

  • supports: Central obesity and the aging brain. (Archives of neurology 2005) · cited 320x in the literature
    "Greater WHR (P = .02) and older age (P<.001) were negatively related to hippocampal volumes. The WHR and age were positively related to white matter hyperintensities (P = .02 and P = .001, respectively). A 1-SD increase in WHR was associated with a 0.2-SD decrease in hippocampal volume and a 27% increase in white matter hyperintensities." (abstract, results, passage verified)
    pubmedfull study (doi)
0:56:58Daniel Amensupportedmoderate

Sixty million Americans have sleep-related disorders.

"60 million Americans have sleep-related issues." (said at 0:56:58)

Standard epidemiological estimates from US public health authorities and published literature indicate that approximately 50 to 70 million Americans suffer from chronic sleep disorders or sleep-related issues, placing the speaker's figure of 60 million directly within the consensus range.

0:57:23Daniel Amensupportedlow

A Montreal Neurological Institute study using SPECT imaging showed significant perfusion decreases in the parietal lobes of individuals with sleep apnea.

"that's actually a published study published last year out of the Montreal Neurological Institute—in SPECT, significant decreases in the parietal lobes, the same area that dies early in Alzheimer's disease, with people who have sleep apnea." (said at 0:57:23)

A 2015 SPECT imaging study evaluating regional cerebral blood flow (rCBF) in 50 untreated obstructive sleep apnea (OSA) patients and 20 age-matched healthy controls found that individuals with severe sleep apnea had significant hypoperfusion in parietal regions—specifically the left parietal lobules and right precuneus—compared to controls. Mild and moderate sleep apnea groups did not show significant rCBF changes compared to controls. The study design is cross-sectional and observational with a modest sample size, placing the body of evidence at low certainty.

0:59:38Daniel Amensupportedvery low

Dr. Amen published a study demonstrating that hypnotic trance decreases Parkinsonian tremors.

"And we ended up—that was one of my first published papers—that in a hypnotic trance, you can decrease parkinsonian tremors" (said at 0:59:38)

Dr. Daniel Amen co-authored an early 1990 paper reporting the reduction of severe Parkinsonian tremor during hypnosis, documented with polygraph/electromyography (EMG) and electroencephalography (EEG) recordings. Because the publication is an uncontrolled single-patient case report, it provides only very low-certainty evidence regarding the clinical efficacy of hypnosis for Parkinson's disease tremors.

0:36:00Daniel Amensupportedhigh

Studies show that anesthesia is associated with decreased overall blood flow to the brain.

"there are a number of studies showing that anesthesia is associated with lower overall blood flow to the brain" (said at 0:36:00)

Multiple functional neuroimaging studies using PET and fMRI demonstrate that general anesthesia (such as propofol-induced anesthesia) significantly decreases global and regional cerebral blood flow (CBF), coupled with reductions in cerebral metabolic demand. Quantitative PET measurements in healthy volunteers show approximately 45% to 50% reductions in total CBF during surgical levels of anesthesia compared with the conscious awake baseline.

7

No source found (not proven false)

0:19:26Daniel Amenunverifiedvery low

A clinic study of 50 consecutive psychiatric patients not taking fish oil found that 49 of them (98%) had suboptimal omega-3 index levels.

"And we did a study here last year where we looked at the omega-3 index on 50 consecutive patients who were not taking fish oil. 49 of them had suboptimal levels. Think about that: 98% of our population—now, we have a skewed population, no, but 98% of a complex psychiatric population has suboptimal levels of omega-3 fatty acids." (said at 0:19:26)

No published record matching a clinic study of 50 consecutive psychiatric patients finding that 49 of them (98%) had suboptimal omega-3 index levels was located; this does not prove the claim false. Although research from psychiatric clinical settings has evaluated omega-3 index levels in relation to cerebral blood flow and cognition, this specific 50-patient clinic audit has not been identified in peer-reviewed literature.

0:28:35Daniel Amenunverifiedvery low

Boxers carrying the APOE e4 gene show cognitive impairment after an average of 11 fights, whereas non-carriers do not show cognitive impairment until after approximately 30 fights.

"So boxers who have the E4 gene, so people have repetitive head trauma, they start to show cognitive impairment after their 11th fight, where those who don't have the E4 gene actually don't show cognitive impairment until after their 30th fight." (said at 0:28:35)

No published record matching the claim that boxers carrying the APOE e4 allele develop cognitive impairment after an average of 11 fights whereas non-carriers develop impairment after approximately 30 fights was located; this does not prove the claim false.

0:09:27Daniel Amenunverifiedvery low

The human brain consumes approximately 20% of the body's total blood flow and 20% of its oxygen.

"your brain uses 20% of the blood flow, 20% of the oxygen, and anything that damages your heart damages your brain." (said at 0:09:27)

No published record matching the claim that the human brain consumes approximately 20% of the body's total blood flow and 20% of its oxygen was located; this does not prove the claim false.

0:27:20Daniel Amenunverifiedvery low

Beets and cayenne pepper have both been shown to increase blood flow.

"for blood flow, it's beets and cayenne pepper. Both of those have been shown to increase blood flow." (said at 0:27:20)

No published record matching the claim that beets and cayenne pepper have both been shown to increase blood flow was located; this does not prove the claim false.

0:28:20Daniel Amenunverifiedvery low

Green tea extract and blueberry extract have been demonstrated to decrease beta-amyloid plaques.

"curcumin and vitamin D have been shown to decrease those plaques, as has green tea extract and blueberry extract." (said at 0:28:20)

No published record matching the claim that green tea extract and blueberry extract decrease beta-amyloid plaques was located; this does not prove the claim false.

0:45:36Daniel Amenunverifiedvery low

Individuals with untreated ADD use medical services at four times the rate of the general population.

"they use medical services four times the level of the general population" (said at 0:45:36)

No published record matching the claim that individuals with untreated ADD use medical services at four times the rate of the general population was located; this does not prove the claim false.

0:50:20Daniel Amenunverifiedvery low

Kris Kristofferson was treated with antibiotics and hyperbaric oxygen for Lyme disease after being misdiagnosed, which allowed him to resume touring.

"And there's a story in the book about Kris Kristofferson, who saw one of our doctors... marked debilitating disease when in fact he had Lyme, and on an antibiotic and hyperbaric oxygen he went back on the road touring." (said at 0:50:20)

No published record matching the claim that Kris Kristofferson was diagnosed with Lyme disease and successfully treated with antibiotics and hyperbaric oxygen allowing him to resume touring was located in the peer-reviewed medical literature; this does not prove the claim false.

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.