It was the first half of the twentieth century and polio was blooming. Historically rare, infection rates started to steadily rise as the decades moved on. Children would develop fever, headache, and muscle weakness. Most of the time the fever would break and strength would return, but not always. Permanent paralysis and deformity were common, leaving thousands regulated to crutches, canes, wheelchairs, or even the iron lung.

Fears grew as the numbers did. During the 1952 pandemic 58,000 American children were infected. More than three thousand died with over 20,000 left paralyzed. A cause was needed. Something we could be warned against, something we could prevent. Well during this polio scare, some scientists stumbled into what has become one of history’s most famous examples of jumping to conclusions.

They declared that ice cream was the problem.

It happened because some watchful experts noticed an interesting correlation. The yearly rates of polio infections seemed to rise in fall in lock step with the consumption of ice cream. The peak summer ice cream season fell during the exact height of polio infections. Studies were performed. Could the virus survive pasteurization? Could it be spread? One Dr. Benjamin Sandler publicized this theory, cautioning parents against feeding their children frozen confections. The excess sugar, he proclaimed, was the cause.

Ice cream sales plummeted.

Now it was true that polio rates did rise during the summer. But looking back, the idea that ice cream causes polio seems absurd. It turns out that the polio outbreaks were actually due to improved sanitation, of all things. As cities and towns became cleaner, children lost early exposure to the polio virus and the valuable immunity it conferred. The summer spike was simply coincidence with natural exposure rates. The scientists had seen a correlation and assumed it was the cause.

Luckily the polio pandemic died off with Jonas Salk and Albert Sabin’s twin polio vaccines. The disease rates suddenly plummeted as children artificially regained the immunity flush toilets had inadvertently taken away. We can only assume ice cream shops were among the most relieved.

Sources: NYTimes, Wikipedia, Smithsonian Magazine, The Hidden Dangers In Polio Vaccine