19. Potassium: An Undeserved Reputation

There’s no avoiding discussing the banana in this episode, even though it really doesn’t deserve its strong association with Element 19.

Featured above: Slickly produced “textbooks” sent to American students in the 1930s.

Show Notes

Whose Law: Tomatoes actually compete with bananas for the title of “most popular fruit” — and are a better source of potassium — but according to US Supreme Court Case Nix v. Hedden (1893), tomatoes are legally classified as a vegetable, and not a fruit.

Since We’re Being Technical: All right, so there is some banana production in the United States, but since it accounts for 0.01% of total world production, I feel confident rounding down to the nearest integer.

Incidentally, I approached it a little sideways in the episode, but while bananas provided a reason to get imperialistic in South America, the excuse in Hawaii was pineapples.

Secret Genius: One of the more notable sources of the “bananas will kill you” myth is Karl Pilkington:

It Ain’t Over: Chiquita is happy to keep peddling banana propaganda to this day. On their website, they attempt to claim that bananas are not fattening because they have “no fat, cholesterol, or sodium … and satisfy your sweet tooth.” No kidding, ya dummies, it’s the sugar that makes them fattening. Just one more example of why it’s important to get your facts from reliable sources.

You’ll probably want to look at the full version here: https://xkcd.com/radiation/

Three Mile Island Wasn’t A Big Deal: One beloved factoid that didn’t make it into the episode is that bananas are measurably radioactive. A certain amount of the potassium in a banana is potassium-40, an unstable isotope.

Though it’s of uncertain origin, some cheeky physicist coined the “Banana Equivalent Dose” to give the lay person a grasp on tiny doses of radiation.

Randall Munroe of xkcd took this to a new level a few years back, providing a sort of logarithmic chart describing the various doses of radiation you’re likely to be exposed to in various scenarios. (The point is, you’re highly, highly unlikely to ever wind up being poisoned by radiation.)

Hawaii’s Last Queen: I was surprised to find that there wasn’t really a good video about the American acquisition of Hawaii on YouTube. The best I found is the following video, though its pace is pretty slow.

That Changes Everything: Eventually, United Fruit Company’s name became too tarnished, what with all the murder and exploitation and whatnot. They changed their name to Chiquita, a name that means “little girl.” A little on the nose there, fellas.

Click To Read Transcript


  1. The Elements of Murder: A History of Poison, p. 376. John Emsley, 2006.
  2. The New York Times, Yes, We Will Have No Bananas. Dan Koeppel, June 18, 2008.
  3. University of Florida, Banana Market. Edward Evans and Fredy Ballen.
  4. The World Banana Economy, Pedro Arias et al.
  5. National Geographic, Why Are Bananas So Cheap? Daniel Stone, August 10, 2016.
  6. A Study Of The Banana: Its Every-Day Use And Food Value (Student’s Manual). United Fruit Company, 1939.
  7. Vox, The Improbable Rise Of The Banana, America’s Most Popular Fruit. Joseph Stromberg, March 29, 2016.
  8. University of Arizona Campus Arboretum, Musa acuminata.
  9. Snopes, Will Eating Too Many Bananas Kill You?
  10. PubMed, Chemical Burn Caused By Dermal Injection Of Potassium Chloride. Park SM, Sohn YD, Ahn JY, June 2011.
  11. Something of a consensus, but just as a for-example, this Quora post.

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