HoldsUp

Ray Dorsey

Ray Dorsey is a physician and researcher working in the field of neurology. His research primarily focuses on Parkinson's disease, covering primary prevention strategies, environmental risk factors, and patient-centered care models. Additionally, his work explores the application of digital health technologies, wearable sensors, and remote AI-based screening tools for neurodegenerative conditions.

49 claims checked on air: 5 context 1 overstated 31 supported 12 unverified

What they said on air - supported

2 citing their own research

0:05:40supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

In his 1817 medical description of the shaking palsy, Dr. James Parkinson described six individuals with the condition.

"Parkinson's disease, according to Dr. James Parkinson when he wrote the major description of the disease in 1817, he said this is a disease that's not been classified in the medical literature. He writes what he in all likelihood thinks is a new disease. He describes six people with the disease in 1817 amongst the industrial revolution in London" (said at 0:05:40)

The claim is fully supported. In his seminal 1817 monograph 'An Essay on the Shaking Palsy', Dr. James Parkinson described the condition as a distinct medical entity not yet properly classified in nosology and detailed the clinical histories of six individuals (cases I through VI) exhibiting the characteristic resting tremor, weakness, and festinant gait.

0:06:07supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

According to the Global Burden of Disease study, approximately 6 million people worldwide had Parkinson's disease as of 2016-2017.

"And 200 years later, the Global Burden of Disease says that 6 million people have the disease." (said at 0:06:07)

The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 systematic analysis published in The Lancet Neurology determined that in 2016, approximately 6.1 million individuals worldwide had Parkinson's disease (95% UI 5.0–7.3 million), more than doubling the 2.5 million estimated in 1990.

0:07:08supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

In the United States, 80 to 90 percent of lung cancer cases occur in people who smoke.

"Even today, 80 to 90% of lung cancer in the United States is in people who smoke." (said at 0:07:08)

The speaker's statement accurately reflects established epidemiological data in the United States. Surveillance and registry data from the CDC and national cancer registries consistently show that 80% to 90% of lung cancer cases and deaths in the US are attributable to cigarette smoking.

0:07:44supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

In the Parkinson's Foundation PD GENEration study of 8,000 individuals with Parkinson's published in Brain, 13% carried a known genetic cause or risk factor, meaning 87% had no known genetic cause or risk factor.

"And last year in a journal called Brain, which you know is one of the top journals in the field, they looked at the genetic testing results of the first 8,000 individuals with Parkinson's disease. Of that 8,000, 13% carry a genetic cause or genetic risk factor for the disease. Said another way, 87% of Americans with Parkinson's, the vast majority of Americans with Parkinson's disease, have no known genetic cause or risk factor for the disease." (said at 0:07:44)

The speaker accurately summarizes the primary findings of the Parkinson's Foundation PD GENEration study (published in Brain), which evaluated genetic testing across a targeted panel of Parkinson's disease (PD)-associated genes (such as GBA1, LRRK2, PRKN, SNCA, and others) in people living with Parkinson's. In the initial cohort of several thousand tested individuals, approximately 13% tested positive for an established causal mutation or clinically relevant risk variant (predominantly in GBA1 and LRRK2), meaning roughly 87% had no identifiable pathogenic or risk-associated variant on the tested panel. Broader multi-ancestry observational cohorts (such as the GP2 initiative partnering with PD GENEration) similarly find that monogenic causal variants occur in ~2.1% of patients and established GBA1/LRRK2 risk variants occur in ~11.8%, corroborating that the vast majority (~86–87%) do not carry known major genetic drivers on standard testing panels.

0:09:15supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

For 2021, the estimated global prevalence of Parkinson's disease was 11.8 million people.

"For 2021, it's estimated it's 11.8 million." (said at 0:09:15)

According to analyses of the Global Burden of Disease (GBD) Study 2021, the estimated global prevalence of Parkinson's disease in 2021 was approximately 11.76 to 11.77 million individuals (which rounds to 11.8 million), rising from around 3.15 million cases in 1990.

0:10:45supportedlowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Exposure to trichloroethylene (TCE) and perchloroethylene (PCE) is associated in a twin study with a 500% increased risk of Parkinson's disease.

"These two chemicals have been associated in a twin study with a 500% increased risk of Parkinson's." (said at 0:10:45)

A 2012 study by Goldman and colleagues evaluated solvent exposures among 99 twin pairs discordant for Parkinson's disease from the NAS/NRC World War II Veteran Twins Cohort. Ever exposure to trichloroethylene (TCE) was associated with a 6.1-fold increased risk of Parkinson's disease (odds ratio 6.1, 95% CI 1.2-33, p = 0.034), which corresponds to an approximate 500% increase in risk. Exposure to perchloroethylene (PERC/PCE) showed an odds ratio of 10.5 (95% CI 0.97-113, p = 0.053). Because this was a retrospective observational study with a relatively small sample size and wide confidence intervals, certainty is rated as low.

0:11:09supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Exposure to the herbicide glyphosate is associated with an increased risk of cancer, specifically non-Hodgkin's lymphoma.

"So glyphosate is associated with cancer and non-Hodgkin's lymphoma." (said at 0:11:09)

The claim is supported by epidemiological meta-analyses and authoritative agency evaluations. In 2015, the International Agency for Research on Cancer (IARC) classified glyphosate as probably carcinogenic to humans (Group 2A), identifying non-Hodgkin lymphoma (NHL) as the primary cancer associated with exposure. A 2019 meta-analysis by Zhang et al. evaluating human epidemiological studies found that high cumulative exposure to glyphosate-based herbicides was associated with a statistically significant 41% increased risk of NHL (meta-RR = 1.41, 95% CI: 1.13–1.75). While some individual cohort studies (such as the Agricultural Health Study) and subsequent analyses have shown mixed or subtype-specific risks (e.g., diffuse large B-cell lymphoma), the epidemiological association between glyphosate exposure and NHL is well-documented.

0:11:20supportedvery lowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Pesticides such as paraquat and chlorpyrifos, as well as air pollution and solvents like TCE and PCE, damage the mitochondria in nerve cells.

"So all the pesticides that have been linked, or many of the pesticides linked to Parkinson's disease—paraquat, chlorpyrifos, these chemicals—and air pollution all damage the energy-producing parts of cells. And the cells that are most susceptible to disruption from mitochondrial toxicants are nerve cells, and among nerve cells it's those nerve cells in the part of the brain called the substantia nigra that are lost or damaged, that likely have enormous energy requirements." (said at 0:11:20)

Preclinical in vitro and animal studies support the speaker's claim. Pesticides associated with Parkinson's disease, such as paraquat and chlorpyrifos, cause mitochondrial fragmentation, impair mitochondrial function, and reduce intracellular ATP levels. Experimental models further demonstrate that exposure to these mitochondrial toxicants leads to selective loss and damage of dopaminergic neurons in the substantia nigra. Because this mechanistic evidence derives primarily from cell cultures and animal models, certainty is rated very low.

0:13:10supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Exposing laboratory mammals (including mice, rats, and rabbits) to paraquat induces features of Parkinson's disease, including tremors.

"According to reporting from The Guardian, it appears that a manufacturer of paraquat did those experiments with three different mammals—mice, rats, and rabbits—in the 1960s. So at least evidence from academics for 30 years and possibly from the manufacturer for 60 years knows that when you expose laboratory animals to paraquat, they develop the features, including a tremor." (said at 0:13:10)

The speaker's claim that exposing laboratory mammals (such as mice and rats) to paraquat induces key pathological and motor features of Parkinson's disease, including tremors and neurobehavioral deficits, is well-established and supported by extensive experimental research across decades. Recent reviews on animal models of Parkinson's disease confirm that paraquat exposure is widely used to reproduce key cellular and motor characteristics of Parkinsonism, including loss of dopaminergic neurons in the substantia nigra, oxidative stress, and motor impairments such as tremors, akinesia, and altered neurobehavioral performance.

0:21:09supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Research by Dr. Virginia Rauh at Columbia University demonstrated that higher levels of chlorpyrifos in umbilical cord blood correlate with lower IQ scores in children at ages 3, 5, and 7.

"Dr. Virginia Rauh here at Columbia University showed exposure to another pesticide called chlorpyrifos was sprayed inside the homes of people in New York City to kill insects. She finds that pesticide in the umbilical cord blood of children. She then follows these children: the higher their level in umbilical cord blood, the lower the IQ at three, five, and seven." (said at 0:21:09)

Research led by Dr. Virginia Rauh at Columbia University evaluated inner-city New York City children whose mothers were exposed to chlorpyrifos during pregnancy. The investigators measured chlorpyrifos levels in umbilical cord blood plasma and followed the children longitudinally. At age 3, higher prenatal chlorpyrifos exposure was significantly associated with lower scores on the Bayley Mental Development Index and Psychomotor Development Index. By age 7, higher umbilical cord chlorpyrifos levels significantly correlated with deficits in Full-Scale IQ and Working Memory assessed via the Wechsler Intelligence Scale for Children (WISC-IV). While formal IQ testing occurred at age 7 and cognitive development was measured at age 3 (rather than continuous annual testing at ages 3, 5, and 7), the core claim accurately reflects Dr. Rauh's findings regarding umbilical cord chlorpyrifos levels and reduced cognitive/IQ performance.

0:21:30supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

A study by Dr. Virginia Rauh published in JAMA Neurology showed that higher prenatal chlorpyrifos exposure is associated with structural brain MRI abnormalities and poorer motor function in children aged 6 to 15.

"And then last month in JAMA Neurology, one of the top journals in the field, she does MRIs of these children now 6 to 15: the higher the level, the more structural brain abnormalities on MRI and the worse the motor function." (said at 0:21:30)

A prospective longitudinal cohort study published in JAMA Neurology evaluated 270 children aged 6.0 to 14.7 years with prenatal chlorpyrifos (CPF) exposure measurements. Higher prenatal CPF levels were significantly associated with dose-dependent structural brain alterations on MRI (including thicker frontal, temporal, and posteroinferior cortices and reduced regional white matter volumes) as well as poorer performance on fine motor and motor programming tasks.

0:23:14supportedlowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

A study by Kimberly Paul and Beate Ritz from UCLA showed that living or working near areas where paraquat is sprayed is associated with a doubling of Parkinson's disease risk.

"A study done by Dr. Kimberly Paul and Dr. Beate Ritz from UCLA showed that simply living or working near where paraquat is sprayed is associated with doubling of your risk of Parkinson's disease." (said at 0:23:14)

A 2024 population-based case-control study led by Kimberly Paul and Beate Ritz at UCLA evaluated ambient residential and workplace exposure to paraquat in 829 Parkinson's disease (PD) patients and 824 community controls in California's Central Valley. Long-term workplace proximity was associated with a 2.15-fold increase in PD odds (OR 2.15, 95% CI 1.46–3.19), and residential proximity was associated with a 1.91-fold increase in odds (OR 1.91, 95% CI 1.30–2.83), directly supporting the claim of an approximate doubling of risk.

0:27:55supportedlowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Studies demonstrate that people diagnosed with Parkinson's disease who continue to be exposed to pesticides experience faster disease progression.

"And indeed, there are studies that have demonstrated that people who already have Parkinson's disease who are exposed to pesticides have a faster rate of progression." (said at 0:27:55)

Observational cohort studies tracking individuals diagnosed with Parkinson's disease (PD) have found that ambient and occupational exposure to specific agricultural pesticides (such as organophosphates, copper sulfate, and MCPA) is associated with faster motor, cognitive, and non-motor symptom progression. Because these findings are derived from longitudinal observational cohorts utilizing geographic information systems and self-reported exposure models, the certainty of evidence is graded as low.

0:28:04supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Studies show that individuals with Parkinson's disease exposed to high levels of air pollution have higher rates of hospitalization.

"And there are studies that suggest that individuals who already have Parkinson's disease, who are exposed to high levels of air pollution, are more likely to be hospitalized for their Parkinson's disease." (said at 0:28:04)

Large-scale epidemiological studies evaluating air pollution and Parkinson's disease (PD) have demonstrated that individuals exposed to elevated levels of air pollutants (such as fine particulate matter [PM2.5], nitrogen dioxide [NO2], and carbon monoxide) have higher rates of hospitalization and emergency department visits for PD. For instance, a nationwide longitudinal analysis of over 10 million Medicare beneficiaries found that continuous high exposure to PM2.5 (90th vs. 0.5th percentile) was associated with significantly increased odds of hospitalization with PD (OR 1.634, 95% CI: 1.489–1.792).

0:31:27supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

PM2.5 particles can directly penetrate the olfactory nerve, carrying toxic metals such as lead from gasoline, iron from brakes, and platinum from catalytic converters into the brain.

"But some are so small, they're 2.5 microns, 1/1000th of a millimeter. They're a 30th the width of my hair. And some directly penetrate the nerve responsible for smell. And they're like a Trojan horse. They're not carrying in troops, but they're carrying in toxic metals into the brain: lead from gasoline, iron from brakes, platinum from catalytic converters." (said at 0:31:27)

Evidence supports the direct nose-to-brain transport of airborne metal-bearing particulate matter via the olfactory nerve and olfactory bulb pathway. Specifically, ultrafine nanoparticles (which form the sub-fraction of PM2.5, generally <200 nm) generated from vehicle combustion, brake wear, and catalytic converter emissions have been shown in toxicological and human autopsy studies to bypass the blood-brain barrier by translocating along olfactory sensory nerve axons directly into the brain, carrying transition metals like iron and other toxic co-pollutants.

0:31:50supportedlowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Toxic metals carried into the brain by air pollution are associated with the misfolding of alpha-synuclein in Parkinson's disease and beta-amyloid in Alzheimer's disease.

"And many of these toxic metals have been associated with misfolding of proteins, a protein called alpha-synuclein in Parkinson's disease, a protein called beta-amyloid in Alzheimer's disease." (said at 0:31:50)

Toxic metals (including airborne metal nanoparticles and heavy metals such as cadmium, mercury, iron, and aluminum) have been extensively demonstrated in observational neuropathology and mechanistic studies to be associated with and induce the misfolding and aggregation of alpha-synuclein in Parkinson's disease and beta-amyloid in Alzheimer's disease.

0:32:18supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Loss of smell is one of the earliest features of Parkinson's and Alzheimer's disease, preceding memory loss and tremor by years or decades.

"And we know one of the earliest features of both these diseases is loss of smell, and which precedes the memory loss and tremor by years, if not decades." (said at 0:32:18)

The speaker's claim is supported by robust clinical and cohort evidence. Olfactory dysfunction (hyposmia or anosmia) is well-established as one of the earliest prodromal features of both Parkinson's disease (PD) and Alzheimer's disease (AD). In PD, loss of smell is a classic non-motor symptom that can precede motor symptoms like tremor by years or even decades. In AD, longitudinal cohort studies demonstrate that olfactory decline is detectable up to 10 years before the clinical onset of cognitive impairment or dementia diagnosis.

0:33:04supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

The economic burden of Parkinson's disease in the United States is $50 billion, and the economic burden of Alzheimer's disease is $300 billion.

"The economic burden of Parkinson's disease in the United States is $50 billion. I think the economic burden of Alzheimer's disease is $300 billion." (said at 0:33:04)

The speaker's estimates closely reflect widely cited national economic analyses in the United States. A comprehensive 2020 analysis published in npj Parkinson's Disease calculated the total economic burden of Parkinson's disease in the US to be $51.9 billion in 2017 (comprising $25.4 billion in direct medical costs and $26.5 billion in indirect/non-medical costs). For Alzheimer's disease and related dementias, the Alzheimer's Association 2020 Facts and Figures report estimated total healthcare, long-term care, and hospice payments at $305 billion for 2020.

0:36:04supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

In 2003, Dr. Heiko Braak proposed that misfolded protein pathology in Parkinson's disease propagates progressively from nerve cell to nerve cell.

"Dr. Heiko Braak in 2003 said that misfolded protein—he didn't say this, but he said misfolded protein spreads from nerve cell to nerve cell, which we now know. He says it's like a fall of a row of dominoes and that process has been triggered and it's ongoing." (said at 0:36:04)

In 2003, Dr. Heiko Braak and colleagues published a landmark neuropathological staging system for Parkinson's disease based on the progressive, stereotypic anatomical spread of alpha-synuclein (Lewy body/neurite) pathology. The model proposed that pathology initiates at specific induction sites (the enteric/vagal system and olfactory bulb) and spreads sequentially across axonally connected vulnerable neuronal populations into the brainstem and cortex.

0:37:24supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

A study in the New England Journal of Medicine showed that exercise decreases the risk of colon cancer recurrence.

"Uh it turns out that exercise can help uh decreases your risk of recurrence of colon cancer in a study in the New England Journal of Medicine." (said at 0:37:24)

A landmark phase 3 multicenter randomized controlled trial published in the New England Journal of Medicine (the CHALLENGE trial) evaluated a 3-year structured exercise program versus health-education materials in 889 patients with resected colon cancer after adjuvant chemotherapy. At a median follow-up of 7.9 years, the exercise group showed a statistically significant 28% reduction in the risk of disease recurrence, new primary cancer, or death (hazard ratio 0.72; 95% CI, 0.55 to 0.94; P = 0.02), with 5-year disease-free survival rates of 80.3% versus 73.9%.

0:39:08supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Clinical trial results for co-enzyme Q10 in Parkinson's disease showed no therapeutic benefit.

"And the the last trial showed no benefit. Now that was at that dose in those individuals." (said at 0:39:08)

The largest and definitive phase III randomized controlled trial of coenzyme Q10 in early Parkinson's disease (the QE3 trial, n=600) evaluated high doses (1200 mg/d and 2400 mg/d) and found no evidence of clinical benefit, terminating early for futility. Subsequent systematic reviews and meta-analyses of randomized trials have confirmed that CoQ10 does not improve motor or non-motor outcomes compared with placebo in Parkinson's disease.

0:43:00supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

There are approximately 1.2 million people with Parkinson's disease in the United States.

"And we want everyone to know about this because if you have Parkinson's disease, among the 1.2 million people with Parkinson's, why not slow that progression? And that's just in the US." (said at 0:43:00)

A landmark 2018 multi-cohort epidemiological study evaluating Parkinson's disease (PD) prevalence across North America calculated that approximately 680,000 individuals aged 45 and older had PD in the United States in 2010, and projected that this number would reach approximately 930,000 by 2020 and 1,238,000 (approx. 1.2 million) by 2030 due to population aging.

0:43:48supportedlowtheir own paperParkinson's Is a Man-Made Disease: The Chemicals Linked to a

A study by Dr. Brittany Krzyzanowski and Dr. Rodolfo Savica in Rochester, Minnesota, found that living within one mile of a golf course was associated with a 126% increased risk of developing Parkinson's compared to living six miles or more away.

"And my colleagues Dr. Brittany Krzyzanowski at Barrow Neurological Institute in Phoenix and Dr. Rodolfo Savica at the Mayo Clinic, a neurologist like David and and me, um they looked at the incidence, number of new cases of Parkinson's in Rochester, Minnesota, where the Mayo Clinic is located, where they have really good data on number of new cases, and they found using sophisticated mapping of golf courses that individuals who lived within one mile of a golf course had a 126% increased risk of developing Parkinson's compared to people who lived six miles or more away." (said at 0:43:48)

A 2025 population-based case-control study by Krzyzanowski, Savica, and colleagues using Rochester Epidemiology Project data analyzed 419 incident Parkinson's disease cases and 5,113 matched controls in Olmsted County/Rochester, Minnesota. After multivariable adjustment for demographic and neighborhood factors, living within 1 mile of a golf course was associated with a 126% increase in the odds of developing Parkinson's disease compared to living more than 6 miles away (adjusted OR 2.26, 95% CI 1.09–4.70). Evidence certainty is rated low due to the observational case-control design.

0:44:28supportedvery lowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

A case report in Annals of Neurology found 18 people living around a golf course who had Parkinson's disease, 15 of whom lived downwind.

"There was an a report small report case report, Annals of uh Neurology, maybe a decade ago found two neurologists found about 18 people who lived around a golf course had Parkinson's disease and 15 of them lived uh downwind." (said at 0:44:28)

A correspondence/case report published in Annals of Neurology in 2012 is titled 'Is living downwind of a golf course a risk factor for parkinsonism?'. As an observational cluster report / letter to the editor, the certainty of evidence for causality is very low, but the speaker accurately described the published report's existence, journal, timeframe, and topic.

0:51:22supportedmoderateParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Farmers who work directly with Paraquat have a 150% increased risk of Parkinson's disease, and people living or working near where Paraquat is sprayed have a 100% increased risk.

"we know the farmer who works with Paraquat has 150% increased risk. And now we know that people who live or work near where that farmer sprays Paraquat have 100% increased risk." (said at 0:51:22)

The speaker's figures closely reflect key observational studies evaluating occupational and ambient paraquat exposure and Parkinson's disease (PD). In the landmark Agricultural Health Study (Tanner et al., 2011), farmers with occupational exposure to paraquat had an odds ratio (OR) of 2.5 (95% CI: 1.4–4.7), which represents a 150% increase in risk. For residential and workplace proximity to agricultural spraying, large population-based studies from California's Central Valley (e.g., Furlong et al., 2024) found that living or working near commercial paraquat applications is associated with odds ratios around 1.91 to 2.15 (a 91% to 115% increased risk, effectively a doubling or ~100% increase).

0:51:33supportedlowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Three studies have shown that green space workers like golf course landscapers have an increased risk of Parkinson's disease.

"We know from three studies have found that green space workers like landscapers on golf courses have increased risk of Parkinson's disease" (said at 0:51:33)

A systematic review on occupational pesticide exposure and health risks in greenspace workers (including gardeners, landscapers, golf course maintenance workers, and nursery employees) identified multiple epidemiological studies evaluating chronic neurological disorders and found elevated risks of Parkinson's disease in this occupational group. Because the underlying evidence base consists of observational cohort and registry studies with variable exposure assessment, the overall certainty is low, but the claim accurately reflects the published literature.

0:54:04supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Jean-Martin Charcot first described amyotrophic lateral sclerosis (ALS) in 1869.

"And not until 1869 did Jean-Martin Charcot, the father of modern neurology, describe ALS." (said at 0:54:04)

Jean-Martin Charcot, often referred to as the father of modern neurology, first characterized and described amyotrophic lateral sclerosis (ALS) in 1869 (with foundational publications and lectures at the Salpêtrière identifying the distinct pathology involving anterior horn cells and lateral corticospinal tracts), establishing it as a distinct clinical-pathological entity.

0:57:10supportedlowParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Paraquat exposure and traumatic brain injury with loss of consciousness interact synergistically to amplify the risk of developing Parkinson's disease.

"So it turns out that exposure to Paraquat increases your risk of Parkinson's disease. Head trauma, loss of consciousness increases your risk of Parkinson's. Together they amplify the risk." (said at 0:57:10)

Epidemiological and preclinical research directly supports the claim. A population-based case-control study (Lee et al., 2012, PMID 23150532) examining 357 incident Parkinson's disease (PD) cases and 754 controls found that traumatic brain injury (TBI) with loss of consciousness for more than 5 minutes was associated with a 2-fold increased risk of PD (AOR 2.00, 95% CI 1.28–3.14), ambient paraquat exposure alone was associated with a modest increase (AOR 1.36, 95% CI 1.02–1.81), and combined exposure to both factors resulted in an approximately 3-fold higher risk (AOR 3.01, 95% CI 1.51–6.01), demonstrating a more-than-additive (synergistic) interaction. Preclinical rodent models also show that TBI primes nigrostriatal dopaminergic neurons to be more vulnerable to subsequent paraquat exposure (PMID 21644813).

1:02:12supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Brain diseases have become the world's leading source of disability.

"brain diseases have become the world's leading source of disability." (said at 1:02:12)

According to the Global Burden of Disease (GBD) 2021 systematic analysis published in The Lancet Neurology, conditions affecting the nervous system (including neurological conditions, neurodevelopmental disorders, and secondary nervous system damage from infectious or neonatal conditions) collectively became the leading cause of global disease burden and disability-adjusted life-years (DALYs) in 2021, accounting for 443 million DALYs and affecting approximately 3.4 billion individuals (43.1% of the global population).

1:02:32supportedmoderatetheir own paperParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Parkinson's disease is one of the world's fastest growing brain diseases.

"There are reasons why Parkinson's is one of the world's fastest growing." (said at 1:02:32)

Global epidemiological analyses, notably from the Global Burden of Disease (GBD) studies and recognized by the World Health Organization (WHO), identify Parkinson's disease as the fastest-growing neurological disorder worldwide in terms of prevalence, disability-adjusted life years (DALYs), and deaths, primarily driven by population aging and increased longevity.

1:02:42supportedhighParkinson's Is a Man-Made Disease: The Chemicals Linked to a

Dementia with Lewy bodies was not described in the medical literature until 1976.

"There are reasons why dementia with Lewy bodies was not described until 1976." (said at 1:02:42)

Dementia with Lewy bodies (initially termed diffuse Lewy body disease) was first described in the medical literature in 1976 by Kenji Kosaka and colleagues, who reported an autopsy case presenting with progressive dementia and widespread Lewy bodies.

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