Popeye the sailorman was a major evangelist for spinach in the 1930s and is said to have increased green consumption in the US by one-third. He loved spinach because the iron content helped him attain super strength.
The only problem was that the “fact” about the iron content in 100 grams of spinach – 35 milligrams – was off by a factor of 10. That’s because a German chemist named Erich von Wolff misplaced a decimal in his notebook in 1870 and that goof created one of the cartoon characters of the century. The story of the decimal point goof has since been retold multiple times, most famously in a book called “Follies and Fallacies in Medicine,” a classic work of evidence-based skepticism first published in 1989.
All these re-tellings miss another important fact – the decimal point explanation is a myth. The mistake arose from faulty measurement methods. Subsequent analyses just improved measurement closer to the currently estimated real value of 2.71 milligrams per 100 grams (roughly 1/10th the believed 35mg).
So, what’s with these myths that get presented to us as facts? And, why is “science” so problematic? More next week..
It’s a lot easier to spread the first thing you find, or the fact that sounds correct, than to delve deeply into the literature in search of the correct fact. – Samuel Arbesman
Source and thanks to: The FiveThirtyEight Blog – Who Will Debunk the Debunkers?