HoldsUp

Michael Snyder

Stanford University

Michael Snyder is the chair of the Department of Genetics and director of the Center for Genomics and Personalized Medicine at Stanford University. His work focuses on personalized medicine, big data, and deep profiling using wearable technology. His published research covers multi-omics analysis, single-cell genomics and proteomics, continuous glucose monitoring, and transcriptomic regulation in human disease.

30 claims checked on air: 2 context 1 contradicted 1 overstated 26 supported 2 flagged

What they said on air - supported

0:05:05supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

COVID-19 infection has been shown to potentially trigger the onset of type 2 diabetes.

"It's very relevant to the current pandemic, in fact, because a lot of people think that COVID might trigger type 2 diabetes. In fact, there's some evidence for that already." (said at 0:05:05)

Multiple systematic reviews and meta-analyses of large cohort studies show that COVID-19 infection is associated with an increased risk of newly diagnosed diabetes, including type 2 diabetes. A meta-analysis of cohort studies encompassing nearly 40 million participants found a significantly higher relative risk of new-onset type 2 diabetes following COVID-19 infection (relative risk 1.70, 95% CI: 1.32–2.19) compared to non-COVID-19 controls.

0:05:18supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Nine out of ten individuals with pre-diabetes are unaware that they have the condition.

"it's pretty clear that actually nine out of 10 people who have pre-diabetes—so not yet diabetes—actually have no idea." (said at 0:05:18)

Nationally representative survey data from the U.S. National Health and Nutrition Examination Survey (NHANES) support the claim that roughly nine out of ten adults with prediabetes are unaware of their condition. In an analysis of U.S. adults meeting laboratory criteria for prediabetes, 92.0% were unaware that they had the condition.

0:05:35supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

In the United States population, 9% of people are diabetic and 33% are pre-diabetic.

"And it turns out that, well, 9% of the US population is diabetic, but 33% are pre-diabetic, and most of those pre-diabetic will go on to become diabetic, and yet they have no idea they're pre-diabetic." (said at 0:05:35)

National epidemiological surveillance data from the United States (such as the National Health and Nutrition Examination Survey and CDC estimates) indicate that approximately 9% to 11% of the total US population (and 14% to 16% of adults) has diabetes, while roughly 30% to 38% (approximately one-third) of adults meet criteria for prediabetes, the majority of whom are unaware of their status.

0:08:10supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Individual glycemic spikes vary widely across different carbohydrate sources, partly driven by the gut microbiome.

"Turns out everybody spikes to different foods differently. Some people spike to bread, other people to bananas, other people to pasta, and it's just different with different people. It's thought that at least part of that's due to what's called your microbiome, the microbes in your gut that digest your food differently." (said at 0:08:10)

Published continuous glucose monitoring studies confirm high interpersonal variability in postprandial glycemic responses to identical carbohydrate foods, and show that gut microbiome composition is a key predictor of these individualized responses. In a landmark study of 800 individuals tracking nearly 47,000 meals, researchers demonstrated substantial person-to-person differences in glucose responses to the same foods and showed that integrating microbiome features alongside clinical and dietary factors accurately predicted individual postprandial glycemic responses. Subsequent trials confirmed marked inter-individual variation in glycemic spikes to specific carbohydrate sources (such as different types of bread) that can be predicted by baseline microbiome profiles.

0:12:25supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Repaglinide functions by stimulating the release of insulin from pancreatic beta cells.

"It's called repaglinide, that actually promotes release of insulin from your pancreas." (said at 0:12:25)

Repaglinide is an established oral insulin secretagogue (meglitinide class) that acts on pancreatic beta-cells by closing ATP-sensitive potassium channels, causing depolarization and stimulating insulin secretion to manage blood glucose in type 2 diabetes.

0:12:47supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Metformin is the most commonly prescribed drug for type 2 diabetes.

"Turns out I'm not a metformin responder, so I don't respond to the most common type 2 drug—type 2 diabetes drug—that's out there." (said at 0:12:47)

Extensive real-world pharmacoepidemiological data and clinical prescribing audits consistently confirm that metformin is the most widely initiated and commonly prescribed medication for type 2 diabetes globally, remaining the standard first-line pharmacotherapy in international clinical practice guidelines.

0:15:51supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Taking a brisk walk 15 minutes after eating white rice substantially reduces the resulting postprandial glucose spike.

"you'll eat white rice and then go eat white rice and then do a brisk walk 15 minutes later, and you'd be amazed at how much it suppresses your glucose spikes." (said at 0:15:51)

Randomized crossover trials and systematic reviews demonstrate that engaging in light to moderate aerobic exercise, such as walking, soon after carbohydrate or meal ingestion substantially attenuates postprandial glucose excursions and peak glucose spikes compared to remaining sedentary. A 2023 systematic review and meta-analysis found that postprandial exercise significantly reduced postprandial glycemic excursions compared to an inactive control (standardized mean difference = 0.55), with shorter intervals between the meal and exercise producing greater suppression of blood glucose spikes.

0:19:24supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Individual molecular profiles across proteins, metabolites, and lipids remain stable over time and remain closer to a person's healthy baseline during acute infection than to another person's profile.

"and it doesn't matter which measurement we use, whether we're following your proteins or your metabolites or your lipids, your pattern will be very, very different than mine, and it'll be fairly stable over time, believe it or not. There will be some things that will change, but for the most part it's the same. But, and not only that, what happens is if you get sick, say you get a viral infection or something else, your profile will shift, but believe it or not, you will still look more like you than me when I'm sick." (said at 0:19:24)

Longitudinal integrative multi-omics profiling studies tracking individuals over years demonstrate that inter-individual differences in molecular profiles (including transcriptomes, proteomes, metabolomes, and lipidomes) generally exceed intra-individual variability over time. In prospective multi-omics cohort studies, baseline molecular profiles remain highly distinct and individualized. When individuals experience perturbations such as acute viral respiratory infections or weight fluctuations, their molecular markers shift dynamically, yet their overall profiles remain closer to their own healthy baseline than to the profiles of other individuals.

0:20:05supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

In a longitudinal deep-profiling study of 109 individuals over three years, 49 participants were diagnosed with significant early-stage health conditions including lymphoma, pre-cancers (MGUS and smoldering myeloma), and heart conditions before becoming symptomatic.

"So in our study, we have 109 people, and just from the first little over three years of profiling, 49, almost half, learned something important about their health. And it was all kinds of different areas. Some was in the area of cancer, some was in the area of cardiovascular, other in the metabolic space. And just as some examples, we caught someone with early lymphoma, two people with pre-cancers—they weren't cancers yet, but they have a good chance of turning into cancer, we caught it early, they're called MGUS and smoldering myeloma—and then there were two people with serious heart issues" (said at 0:20:05)

In a prospective longitudinal multi-omics profiling study of 109 individuals published in Nature Medicine (Schüssler-Fiorenza Rose et al., 2019, led by Michael Snyder's group), deep profiling over a median of 2.8 years revealed 67 clinically actionable health discoveries across 49 participants. These included early detection of lymphoma, plasma cell disorders (MGUS and smoldering myeloma), cardiovascular conditions, and metabolic diseases before clinical presentation.

0:28:20supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Blood oxygen saturation levels drop during commercial airline flights.

"I always wear a pulse ox because it turns out your blood oxygen drops on airline flights. Most people don't know that. Most pilots do, most flight attendants don't. But anyway, your blood oxygen does drop." (said at 0:28:20)

Commercial aircraft cabins are typically pressurized to an equivalent terrestrial altitude between 5,000 and 8,000 feet (1,500 to 2,400 meters). The resulting reduction in ambient barometric pressure and oxygen partial pressure causes a measurable, physiological drop in arterial blood oxygen saturation (SpO2) in healthy passengers. Studies measuring in-flight SpO2 in adults and children consistently demonstrate that blood oxygen levels drop from normal sea-level baseline values (~97–99%) down to approximately 92–95% at cruising altitude.

0:29:00supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Doxycycline is the standard antibiotic therapy used to treat Lyme disease.

"I said, "No, I need doxycycline," which is what you use for Lyme." (said at 0:29:00)

Clinical practice guidelines and infectious disease consensus establish oral doxycycline as the standard, first-line antibiotic treatment for most manifestations of Lyme disease (Lyme borreliosis), including localized erythema migrans, early disseminated disease, and neuroborreliosis.

0:31:05supportedlowDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Smartwatch resting heart rate elevation detected illness prior to symptom onset in all monitored illness episodes across four individuals.

"And so retrospectively, we could show every single time I got ill, my heart rate jumped up early, and it was in advance of symptoms. It worked on me, and it worked on three other people who also were ill and were wearing the same smart watch—one of them got sick twice. Every single time, we could see the jump up in heart rate before symptoms." (said at 0:31:05)

The speaker accurately describes the findings of their 2017 proof-of-concept study published in PLOS Biology (PMID: 28081144). In that investigation, continuous physiological monitoring via wearable biosensors (smartwatches) tracked physiological baseline fluctuations in the primary participant (who developed Lyme disease and viral infections) and three additional participants (one of whom experienced two separate illness periods). Retrospective analysis demonstrated that resting heart rate and skin temperature significantly increased prior to or at the earliest onset of clinical symptoms across all observed illness events. Because this was a small observational case series of four individuals, the certainty of evidence for broad generalizability is low, though the claim accurately reflects the published findings.

0:32:07supportedlowDr. Michael Snyder on Continuous Glucose Monitoring and Deep

In a study of 32 individuals wearing a Fitbit during COVID-19 infection, resting heart rate elevation was detected in 26 of 32 (81%) cases at or before symptom onset.

"With 32 people wearing a Fitbit at the same time they had COVID and they had a diagnosis date and a symptom date, we showed that for 26 of the 32, we could detect the jump up of resting heart rate. And basically, in nearly all cases, it was at or before symptoms, so 81% of the time we can see people's resting heart rate jump up with COVID." (said at 0:32:07)

A 2020 observational study by Mishra et al. (from the Snyder laboratory) evaluated physiological and activity tracking data from 32 individuals diagnosed with COVID-19. The study reported that 26 of 32 participants (81%) exhibited detectable physiological alterations (primarily elevated resting heart rate standardized against baseline steps). Among the 25 detected cases with recorded symptom dates, 22 (88%) were identified at or before symptom onset. Because this was an observational feasibility study with a small sample size (n = 32), the overall body of evidence certainty is rated as low.

0:32:38supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Resting heart rate increases on average about 4 days prior to symptom onset in people infected with COVID-19.

"On average, though, it's about four days. So people's heart rate will jump up four days before their symptoms if they have COVID, it turns out, and that we can pick up with a smart watch." (said at 0:32:38)

Published cohort studies investigating consumer smartwatches and fitness trackers demonstrate that physiological shifts—primarily increases in resting heart rate relative to an individual's baseline—occur before symptom onset in individuals infected with COVID-19. Studies utilizing retrospective and real-time smartwatch monitoring (e.g., Mishra et al., Nature Biomedical Engineering 2020 and follow-ups) observed resting heart rate elevations beginning a median/mean of approximately 3 to 4 days (and in some cases up to 9 or more days) prior to self-reported symptom onset, allowing detection in roughly 63% to 78% of presymptomatic cases.

0:33:29supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

A real-time wearable monitoring algorithm detected COVID-19 and alerted individuals at or before symptom onset in 44 out of 63 cases (70%).

"So 70% of the time, we can detect illness. We had 63 people as of the end of January who had COVID, and 44 that we could detect in real time and alert them before or at the time of symptoms." (said at 0:33:29)

The speaker accurately describes interim results from Stanford's prospective wearable study evaluating an online alerting algorithm for COVID-19 detection. The final published study in Nature Medicine followed a cohort of 3,318 participants and found that the real-time smartwatch alerting system detected pre-symptomatic and asymptomatic SARS-CoV-2 infection in 67 of 84 infected individuals (80%), with alerting signals occurring at a median of 3 days prior to symptom onset.

0:35:42supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Smartwatches can detect atrial fibrillation and measure electrocardiograms.

"you can actually pick up atrial defibrillation—basically AFib, as it's called, can get picked up with your smart watch. Right now there's a high false positive rate, but some people have picked that up from their smart watch. You can even get an electrocardiogram measurement from Apple Watch, you may know, and some other devices now." (said at 0:35:42)

Smartwatches can record single-lead electrocardiograms (ECGs) and detect episodes of atrial fibrillation (AFib) through both optical photoplethysmography (pulse monitoring) and integrated ECG sensors. Large-scale prospective studies, such as the Apple Heart Study (n = 419,297), confirmed that smartwatch algorithms can detect irregular rhythms indicative of AFib, with an 84% positive predictive value during concurrent ECG patch monitoring. In addition, FDA-cleared smartwatch single-lead ECG accessories and built-in features have demonstrated high sensitivity (e.g., 94.4%) for AFib detection compared to gold-standard 12-lead ECGs, while also exhibiting false-positive findings or unclassified readings in non-clinical settings as noted by the speaker.

0:44:25supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Studies show that children living in high-pollution areas such as Fresno, California, have a significantly higher incidence of allergies and asthma.

"kids in these poor areas like in Fresno where there's a lot of pollution, where there's a lot of firefighters, there's a lot of studies that show that they have a much, much higher incidence of allergies and asthma when they're in these areas" (said at 0:44:25)

Extensive research, including the Children's Health and Air Pollution Study (CHAPS) conducted in Fresno, California, supports the claim that children living in high-pollution areas such as Fresno experience higher rates of asthma exacerbations, respiratory symptoms, allergic inflammation, and immune dysfunction linked to atopy. Observational and clinical studies in Fresno children demonstrate that ambient air pollutants (such as polycyclic aromatic hydrocarbons, NO2, and coarse particulate matter) are significantly associated with epigenetic changes (e.g., FOXP3 hypermethylation), impaired regulatory T-cell function, elevated IgE levels, and increased wheeze and asthma severity.

0:49:02supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Deep molecular profiling of 43 people followed longitudinally identified distinct personal aging patterns categorized into kidney, liver, immune, and metabolic ageotypes.

"Yeah, and so in the end, we had 43 people with enough data we could group them into these classifications—ageotypes, we like to call them. 'What's your ageotype?' And it was kidney, liver, immune, and metabolic aging." (said at 0:49:02)

A 2020 longitudinal multi-omics profiling study led by Michael Snyder's group (published in Nature Medicine) followed 106 individuals and analyzed 43 participants with sufficient longitudinal time points over two years, identifying distinct individual aging pathways termed 'ageotypes', which primarily included kidney, liver, metabolic, and immune ageotypes.

0:53:06supportedlowDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Observational research observed that diabetic patients taking metformin had longer survival than non-diabetic controls.

"The first observation was that diabetics on metformin seemed to live a little bit longer than normal people." (said at 0:53:06)

A landmark retrospective observational study using the UK Clinical Practice Research Datalink (CPRD) by Bannister et al. (2014) reported that patients with type 2 diabetes initiated on metformin monotherapy had longer survival than matched non-diabetic controls (adjusted median survival time was 15% lower in the matched non-diabetic controls). Subsequent longer-term observational analyses (e.g., Keys et al., 2023) confirmed this survival advantage in the initial years of follow-up (up to 3 years), though they noted that the survival advantage reverses after 5 years over a 20-year follow-up period due to the cumulative health impact of type 2 diabetes. Because the underlying evidence is observational, overall certainty is low due to potential residual confounding.

0:56:30supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

The NIH is running a 170-million-dollar study to investigate the molecular benefits of aerobic versus resistance training.

"There's a study run by NIH that's launching now—or launched a few years ago, but we're in the middle of it. It's a 170-million-dollar study to try and understand the benefits of exercise: both aerobic training, so running, biking, versus resistance training, and see what promotes what benefits and how does it work." (said at 0:56:30)

The speaker accurately describes the Molecular Transducers of Physical Activity Consortium (MoTrPAC), an initiative supported by the NIH Common Fund with an initial funding allocation of approximately $170 million. As detailed in its study protocols and consortium overview, MoTrPAC includes large-scale clinical trials and preclinical animal models to map the multi-omic and molecular mechanisms underlying exercise adaptations, specifically comparing the effects of endurance (aerobic) exercise and resistance exercise.

0:57:13supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Approximately half of measured molecules in the body change significantly after running to VO2 max.

"We did these same deep molecular measurements on people who did exercise. We discovered half your molecules change when you run to what's called your VO2 max." (said at 0:57:13)

A 2020 study by Contrepois, Snyder, and colleagues published in Cell performed deep multi-omic profiling (including the transcriptome, proteome, metabolome, lipidome, and immunome) in 36 individuals undergoing acute symptom-limited cardiopulmonary exercise testing to peak oxygen consumption (VO2 max). The longitudinal time-series analysis revealed that approximately half of all profiled analytes (thousands of distinct molecules in blood and peripheral blood mononuclear cells) changed significantly in response to the acute exercise bout.

0:57:13supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

VO2 max is an indicator of longevity and one of the best predictors of lifespan.

"Your VO2 max is also an indicator of longevity. It's actually one of the best indicators of longevity." (said at 0:57:13)

Cardiorespiratory fitness (quantified as VO2 max or maximal aerobic capacity) is robustly established as one of the strongest independent predictors of all-cause mortality and longevity. In a meta-analysis of 33 cohort studies encompassing 102,980 individuals (Kodama et al., 2009), each 1-MET increase in aerobic capacity was associated with a 13% reduction in all-cause mortality risk. Furthermore, large cohort data from 122,007 patients (Mandsager et al., 2018) demonstrated that low cardiorespiratory fitness was associated with a 5-fold increase in all-cause mortality compared with elite fitness, demonstrating a prognostic impact comparable to or exceeding traditional risk factors such as smoking, coronary artery disease, and diabetes.

0:58:00supportedmoderateDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Immune function declines significantly with aging, particularly in people in their 60s.

"Why is it that old people get cancer? Well, what happens, your immune system declines, especially in those people in their 60s, and so suddenly these cancer cells that you've been clearing are getting hold and then they can actually, you know, burst out and get cancer." (said at 0:58:00)

Age-related deterioration of the immune system (immunosenescence) is a well-established phenomenon characterized by progressive thymic involution, reduced T-cell repertoire diversity, impaired innate and adaptive immune cell function, and chronic low-grade inflammation (inflammaging). These alterations significantly impair antitumor immunosurveillance, contributing alongside somatic mutation accumulation to the marked increase in cancer incidence observed in older adults, particularly from the sixth decade of life onward.

1:00:49supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

The recommended daily intake of dietary fiber is approximately 30 grams, but most people only consume around 12 to 15 grams per day.

"you're supposed to get about 30 grams of fiber a day, and most people get about 12, sometimes 15." (said at 1:00:49)

The speaker's statement accurately summarizes established dietary reference intakes and national surveillance data. Guidelines recommend 14 g of dietary fiber per 1,000 kcal (equating to 25 g/day for adult women and 38 g/day for adult men, or approximately 30 g/day on average), whereas typical intake among adults in the United States averages roughly 15 g/day (ranging from 12 to 18 g/day depending on subgroup).

1:03:22supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Arabinoxylan, which is found in psyllium, clearly lowers blood cholesterol levels.

"which is arabinoxylan, which is found in psyllium, will actually drop your cholesterol. That one's pretty clear." (said at 1:03:22)

Arabinoxylan is the primary active, gel-forming soluble fiber component of psyllium husk (Plantago ovata), responsible for binding bile acids and increasing their fecal excretion. High-quality clinical trial evidence, including multiple systematic reviews and meta-analyses of randomized controlled trials, confirms that psyllium and isolated arabinoxylans significantly reduce total cholesterol and LDL cholesterol in a dose- and time-dependent manner.

1:04:55supportedhighDr. Michael Snyder on Continuous Glucose Monitoring and Deep

Dietary fibers generally increase beneficial gut microbes such as Bifidobacterium and Lactobacillus, which produce short-chain fatty acids that support immune function.

"the Bifidobacter and Lactobacillus, those are your beneficial microbes, as you probably know. And so in general, things and fibers generally increase both of those, so that's one way in which they promote—they're thought to actually make something called short-chain fatty acids, which give your immune system a boost." (said at 1:04:55)

The claim is supported by extensive human clinical trial evidence and systematic reviews. Fermentable dietary fibers (prebiotics such as inulin, fructooligosaccharides, and galactooligosaccharides) selectively stimulate the growth of beneficial gut bacteria, particularly species within the genera Bifidobacterium and Lactobacillus. These microbes, among others, ferment fiber into short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which modulate immune responses, reduce inflammation, and enhance mucosal immune defenses.

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