There’s no evidence that eating cucumbers stops lung cancer

12 May 2021
What was claimed

Cucumber kills cancer cells.

Our verdict

There’s no evidence that eating cucumbers has any effect on treating lung cancer.

What was claimed

A study from India showed people eating cucumber every day had a 71% less risk for lung cancer.

Our verdict

No studies show this. One study showed people who ate green vegetables were less likely to get lung cancer but the paper’s authors said this couldn’t be narrowed down to one vegetable’s effect.

A post on Facebook has made a number of claims about cucumber’s ability to kill cancer cells. This is mostly based on evidence that looks at one chemical present in cucumbers and its ability to kill cells in the lab and in mice, rather than any evidence showing that specifically eating cucumbers prevents cancer in humans.

None of the scientific papers cited in the post show that eating cucumber can prevent or treat lung cancer. 

One study the author refers to looked at the effect of a chemical called cucurbitacin B (found in cucumbers, and other foods like pumpkins and gourds) on tumour cell growth in both cells in the lab and in mice. It found that cucurbitacin B on its own or in combination with a chemotherapy drug slowed the growth of tumour cells. But this doesn’t prove that this chemical in isolation would be effective at treating lung cancer in humans, and definitely doesn’t prove that eating cucumber has the same benefits. 

Since we published this article, the post’s author has amended the caption accompanying the image with a correction clarifying that we don’t know if cucumbers have any ability to prevent cancer in humans.

The post also included a claim that research from India has shown that “people eating cucumber every day had a remarkable 71% less risk for lung cancer.”

We were not able to find any papers that supported this claim. Fact checkers Science Feedback also wrote about this post, and following that, the post’s author contacted them with details of a study he was referring to, and updated his post to include this link. 

As Science Feedback wrote, that study did not prove that eating cucumbers prevented lung cancer. It looked at the diets of several hundred people, including a group that ate certain types of green vegetables, including cucumber. It found that consuming these foods was associated with lower rates of lung cancer. The paper concludes that diet in general has a role in causing lung cancer, but the association is weak compared to the effect of smoking.

Update 3 June 2021

We updated this article to reflect that the author of the Facebook post corrected their caption.

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