Yes, Toxic Squash Syndrome Is a Thing
You might roll your eyes and dismiss it outright if you've never heard of it, but a published report in the Journal of the American Medical Association Dermatology shows that "toxic squash syndrome"—also known as cucurbit poisoning—could be a concern for home cooks.
The report highlights two separate cases involving women in France, who became sick after eating bitter-tasting squash.
Both women became extremely ill immediately following their meals, and were later diagnosed with the the syndrome. Both women also lost nearly all of their hair, which is an unfortunate side effect.
The bitterness is a sign that the squash in question contain high levels of chemical compounds known as cucurbitacins. The compounds occur naturally in wild squash plants and act as defense against herbivores—they do not typically exist in cultivated squash, except when accidental cross-pollination occurs according to Newsweek. If your squash, cucumber, melon, or zucchini tastes alarmingly bitter, it's a telling sign that it might not be safe to eat.
Bustle did a deep dive into why toxic squash syndrome is so dangerous (even deadly) for home cooks—their report highlights a 2010 case where a man nearly died after drinking freshly squeezed gourd juice.
According to Dr. Shravan Bohra, gastroenterologist at Ahmedabad Apollo Hospital in India who treated the man, the toxins in the cucurbitacin-loaded gourd juice caused swelling in the liver, gallbladder, kidney, and pancreas.
In 2015, a German man died after eating a zucchini packed with the deadly toxin, as reported by The Daily Meal.
It there's one thing that's clear, it's that you should probably avoid eating extremely bitter squash or cucumbers.
And don't brush the possibility of getting sick aside: a CBS report included data from squash poisoning within the United States over the last year, and there have been more than 17 cases over the last 12 years.