FACT CHECK: Do Onions Absorb Harmful Bacteria?

Hannah Hudnall | Fact Check Reporter

A lengthy post shared on Facebook claims onions that are left out will absorb harmful bacteria thereby keeping people around them healthy.

Verdict: False

There is no scientific evidence to support this claim, according to various experts.

Fact Check:

Onions have been at the center of several myths throughout the years, with some people claiming they promote hair growth while others claim they can cure cancer, according to the National Onion Association (NOA). Now, a lengthy post shared on Facebook claims that onions are capable of absorbing harmful bacteria.

The post claims that in 1919, amid a major influenza pandemic, a doctor traveled to a farmer’s house where he intended to help protect them from the disease, but instead was amazed to find all the inhabitants of the home healthy. (RELATED: Viral Image Claims Hand Sanitizer Poses A Threat To Pets Because It Contains A Toxic Chemical Also Found In Antifreeze)

“When the doctor asked what the farmer had done, his wife said he had placed an unpeeled onion in a dish in the rooms of the house,” reads part of the post. “The doctor couldn’t believe it and asked if he could have one of the onions, which he placed under a microscope. As a result, he found *the flu virus in the onion!! Meaning the onion had absorbed the bacteria* therefore keep the family healthy.”

The post goes on to claim that this alleged ability of onions to absorb bacteria makes them poisonous after a certain period of time.

There is no evidence that onions absorb bacteria or protect people from disease by drawing germs out of the air, according to the NOA. A section of the association’s website explains that the vegetable’s juices are actually antimicrobial, meaning they repel bacteria rather than absorb it.

In addition to this, onions excrete sulphuric acid, lack any protein and quickly dry out, all features that make the vegetable a non-ideal place for bacteria to accumulate or grow, according to an article published by McGill University’s Office for Science and Society.

“This is an ancient belief supported by no scientific evidence,” said Dr. Francisco Diez-Gonzalez, a professor of food science and technology at the University of Georgia, in an email to Check Your Fact. 

Hannah Hudnall

Fact Check Reporter