This Podcast Will Kill You

Ep 196 Health Myths: Fact or fiction?

December 16, 2025

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  • The episode of "This Podcast Will Kill You," Ep 196 Health Myths: Fact or fiction?, will explore popular health myths, examining their origins and searching for any underlying truth, often challenging long-held beliefs rooted in oral tradition. 
  • The term "old wives' tale" historically carries dismissive connotations due to prejudices against knowledge generated by women before the establishment of systematic science. 
  • The myth that going out in the cold with wet hair causes illness is rooted in ancient humoral theory and miasma beliefs, but modern data suggests cold exposure itself does not cause colds, though environmental factors like humidity and temperature drops may influence viral replication. 
  • Ginger may be helpful for nausea and vomiting due to potential interaction with serotonin receptors and increased gastric motility, but achieving the studied therapeutic dose (1 gram/day) is difficult with common consumer products like ginger ale or chews. 
  • The efficacy of ginger for nausea is complicated because it is not a licensed drug product, meaning the actual amount of active compound received from teas, chews, or sodas is highly variable and often insufficient compared to clinical study amounts. 
  • The hosts listed numerous other popular health myths for future investigation, including 'feed a cold, starve a fever,' 'cracking your knuckles,' 'gum in your stomach,' and 'cranberry juice and UTIs.' 

Segments

Podcast Introduction and Format
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(00:02:38)
  • Key Takeaway: The episode of This Podcast Will Kill You will investigate health myths, deviating from the usual format by omitting a first-hand account.
  • Summary: Hosts Erin Welsh and Erin Owen Updike introduce the episode focusing on health myths, noting the absence of their typical first-hand account. They plan to explore a handful of these myths, which they refer to as old wives’ tales, to determine their factual basis. The chosen quarantini for the episode is named ‘The Miracle Cure,’ consisting of ginger ale, carrot juice, and lime juice.
Defining Old Wives’ Tales
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(00:07:50)
  • Key Takeaway: Old wives’ tales are superstitious, outdated beliefs often carried through oral tradition, historically disparaged by formal science which was primarily documented by men.
  • Summary: The hosts define old wives’ tales as superstitious, outdated beliefs passed down through oral tradition, often from woman to woman before male physicians dominated medicine. This historical context contributed to the term being used dismissively, suggesting that knowledge held by women was rarely written down or taken seriously by those in power. Despite many being false, some traditional knowledge may contain a nugget of scientific truth, warranting examination rather than immediate dismissal.
Myth 1: Wet Hair and Cold
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(00:12:56)
  • Key Takeaway: The belief that going out in the cold with wet hair causes illness stems from pre-germ theory concepts like humoral imbalance and miasma, but cold exposure itself does not cause colds.
  • Summary: The myth that wet hair in the cold leads to death or sickness is deeply rooted in 19th-century literature reflecting humoral theory, where cold was thought to cause obstructions and fevers. Modern science confirms that viruses, not cold or dampness, cause colds, although some studies suggest cold exposure might slightly increase susceptibility or viral replication efficiency in the respiratory system. Furthermore, the idea that 50% of body heat is lost through the head is false; heat loss is proportional to exposed surface area, meaning uncovered legs would lose more heat than an uncovered head.
Myth 2: Carrots and Night Vision
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(00:29:11)
  • Key Takeaway: The myth that carrots grant night vision originated as British WWII propaganda to conceal the use of radar technology, though Vitamin A deficiency does cause actual night blindness.
  • Summary: The popular belief that eating carrots grants night vision was promoted by the British Ministry of Food during WWII to encourage consumption of carrots, which were in surplus, while simultaneously masking the success of pilots using new radar technology. While Vitamin A (derived from beta-carotene in carrots) is essential for vision, and a deficiency causes night blindness, eating extra carrots will not grant superhuman night vision to those who are not deficient. Excessive beta-carotene supplementation, particularly in smokers, has been linked to an increased risk of lung cancer.
Myth 3: Sugar Rush
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(00:41:43)
  • Key Takeaway: Scientific evidence overwhelmingly shows no causal link between sugar consumption and hyperactivity in children, though parental perception of behavior is significantly influenced by the expectation of a sugar rush.
  • Summary: The concept of a sugar rush causing hyperactivity in children only gained traction in the 1970s, popularized by a book linking hyperactivity to food additives and sugary snacks, despite lacking evidence. Over twelve double-blind, placebo-controlled trials have since found no association between sugar intake and actual changes in children’s behavior or ADHD symptoms. Interestingly, studies show that parents who are told their children consumed sugar rate their children as more hyperactive, suggesting the effect is largely based on expectation rather than biochemistry.
Myth 4: Ginger Ale for Tummy Aches
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(00:55:48)
  • Key Takeaway: While ginger itself shows evidence for reducing nausea and vomiting, especially related to pregnancy and chemotherapy, store-bought ginger ale often contains no real ginger and is unlikely to deliver the necessary therapeutic dose.
  • Summary: Ginger has been recognized for thousands of years in various medical traditions for aiding digestion and reducing nausea, with modern studies supporting its benefit for nausea associated with pregnancy and chemotherapy. The non-alcoholic beverage ginger ale was historically marketed as a health tonic, but most commercial versions today use only ginger flavoring, not enough actual ginger to reach the therapeutic dose (at least one gram) used in studies. Consuming large amounts of carbonated ginger ale may also exacerbate acid reflux, a potential side effect of ginger consumption.
Ginger and Serotonin Receptors
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(01:03:14)
  • Key Takeaway: Ginger compounds may interact with serotonin receptors, similar to anti-emetics like Zofran.
  • Summary: Compounds in ginger might interact with serotonin receptors, drawing a parallel to how anti-emetics such as Zofran (Ondansetron) function in the brain. Ginger may also help increase gastric motility. This mechanism is likely why people associate ginger ale with stomach relief.
Ginger Ale Efficacy Limitations
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(01:03:43)
  • Key Takeaway: Ginger ale lacks sufficient real ginger content to reach therapeutic doses, and carbonation may counteract benefits via acid reflux.
  • Summary: There is no specific data supporting the use of ginger ale for nausea relief. Most commercial ginger ales contain no actual ginger, and even those with real ginger make it nearly impossible to consume the required one gram dose daily. Furthermore, consuming carbonated beverages can cause acid reflux, a side effect also associated with consuming high amounts of ginger.
Ginger Dosing Consistency Issue
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(01:04:30)
  • Key Takeaway: The inconsistency in dosing across non-licensed ginger products prevents reliable therapeutic outcomes for nausea and vomiting.
  • Summary: Similar to issues discussed in the supplements episode of This Podcast Will Kill You, the dosage of ginger in capsules, chews, teas, or sodas is not standardized or licensed. This makes it difficult for consumers to ingest the amount of ginger used in studies that show efficacy for nausea and vomiting.
Conclusion and Future Myths
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(01:05:07)
  • Key Takeaway: The ginger myth is classified as ‘Myth clarified,’ and the hosts previewed several other myths for future episodes, including ‘feed a cold, starve a fever.’
  • Summary: The conclusion regarding ginger’s role in nausea is ‘Myth clarified,’ indicating some truth but with significant caveats regarding dosage. The hosts listed many other potential myths to investigate, such as joint aches in the cold, cracking knuckles, and the effect of sugar on children’s energy levels.
Source Citation Review
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(01:06:37)
  • Key Takeaway: The sources for debunked or clarified myths included academic dissertations, specific journal articles (like those on beta-carotene and viral infections), and books on the history of soda and candy.
  • Summary: Sources cited for the ‘wet hair/cold’ myth included dissertations on Victorian literature and climate. The evidence for beta-carotene and eye health relied on major studies like the Age-Related Eye Disease Studies (2001 and 2013 updates). The sugar rush myth referenced the highly cited 1986 study by Crummel et al., titled ‘Hyperactivity: Is Candy Causal?’