False claim that eating seedless watermelon causes cancer

The claim: Eating seedless watermelons treated with colchicine can cause cancer, infertility and more

Social media users are warning against the purported dangers of seedless watermelon.

“Eating seedless watermelon treated with colchicine can cause cancers, severe liver and kidney issues and infertility and birth defects,” reads the caption of a¬†Sept. 7 Instagram post. “Eat ONLY BLACK seeded watermelon.”

The post features a screenshot of a Google search result explaining that seedless watermelons are bred with the use of the chemical colchicine, which came from a North Carolina State University page.

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The post garnered more than 600 likes in its first week. The same user posted the claim on Facebook, where it garnered more than 100 shares in its first week.

The claim is false. Experts say there are no known safety risks associated with eating seedless watermelons. And the watermelon sold in stories are many generations removed from anything that was directly treated with colchicine.

USA TODAY reached out to the user who shared the post for comment.

Chemical not used directly on watermelons bought in stores

Seedless watermelon plants can be created by crossing a normal watermelon with one that has been treated with the chemical colchicine, according to the University of Florida Institute of Food and Agricultural Sciences. The chemical doubles the chromosomes in the watermelon and helps produce a plant that, when pollinated, develops seedless watermelons.

But that’s only the first step in a lengthy process, said¬†Rebecca Wente-Naylor, a Syngenta Vegetable Seeds spokesperson.

“On average, it takes six to eight years to produce a seedless watermelon,”¬†Wente-Naylor said.. This factors in 10 generations to produce the female parent, six generations to produce the male parent, and another five to eight generations of advanced testing in several environments

And only the first generation in that process is directly treated with colchicine.

“The seedless watermelons we eat never received the colchicine treatment as they are many generations later than the initial seedless watermelon,” said Dr. Brian Leyland-Jones, a spokesman for the¬†National Foundation for Cancer Research.

Colchicine is FDA-approved

Officials say there is no evidence of health concerns with seedless watermelon.

“The FDA is not aware of any safety issues with commercially-bred seedless watermelon,” an FDA spokesperson told USA TODAY.¬†

Colchicine is also a Food and Drug Administration-approved treatment for acute gout flares. 

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Leyland-Jones said the cancer foundation has not observed any link between seedless watermelons and cancer. He said the opposite is actually true.

“Watermelon, seedless ‚Ästwith white seeds ‚Äď or with black seeds, is a healthy fruit containing the carotenoid, lycopene,” he told USA TODAY. “In our body, lycopene deactivates reactive oxygen or free radicals, which play a significant role in initiating the malignant transformation of cells.”

Lycopene is an antioxidant and “anti-cancer nutrient,” and antioxidants can help prevent illnesses like diabetes and heart disease, according to the National Foundation for Cancer Research.

Our rating: False

Based on our research, we rate FALSE the claim that eating seedless watermelons treated with colchicine can cause cancer, liver and kidney disease, infertility and birth defects. Experts from the FDA and the National Foundation for Cancer Research said seedless watermelons are safe to eat. 

Our fact-check sources:

  • FDA, July 10, 2015, Colchicine (marketed as Colcrys) Information
  • North Carolina State University, July 20, 2012,¬†What‚Äôs the Deal With Seedless Watermelons?
  • The National Foundation for Cancer Research, July 14, 2021,¬†Cancer-Fighting Food: Watermelon
  • The journal Rhuematology, Sept. 23, 2017,¬†Use of colchicine in pregnancy: a systematic review and meta-analysis¬†
  • FDA spokesperson, Sept. 12, Email exchange with USA TODAY
  • Dr. Leyland-Jones, Sept. 13, Email exchange with USA TODAY

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