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

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.

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.