FIT WebQoof: No, Onions Cannot Absorb Bacteria to Prevent the Flu

This hoax has been around since the 1500’s, when the bubonic plague was at its peak.

This message, going back to the 1500s, is a hoax. Onions can help relieve a cold but cannot prevent it.

(Photo: Arnica Kala/The Quint)

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CLAIM: A message on social media has been going viral, with the claim that onions absorb bacteria and so when left outside they can keep the bacteria away from you. But because of this onions left outside should not be consumed.

The same message has been swirling around on various social media platforms throughout the years. The first time it surfaced and went viral was in 2009, when Swine Flu broke out and more people wanted to avoid catching the virus.

A simple search with a few keywords from the post threw up many results from years past.(Photo: Twitter)

True or False?

According to renowned mythbusting site Snopes from 2009, this message has no scientific legs. In fact, the article alleged that this piece of fake news possibly originated even earlier, around the 1900’s during other epidemics like smallpox and the USA’s National Onion Association claimed it was around since the 1500s during the bubonic plague!

Onions Cannot Attract Viruses Say Doctors

FIT spoke to nutritionist Ritika Samadar of Max Hospital to clear up doubts regarding claims of onions preventing the flu.

This is a myth. However, keeping uncut fruits and vegetables or even meat and prepared foods out during humid and hot seasons is not advisable. Any fruit or vegetable with a high water content can attract microorganisms and become a source of infection.

Ritika Samadar

“The flu, cold and cough are all are viral infections. Food-related bacterial infections are typhoid, jaundice and cholera,” she adds.

In 2009, the National Onion Association in the US addressed this claim saying it had no merit and that “After being cut, onions can be stored in the refrigerator in a sealed container for up to seven days.”

A Wall Street Journal article from 2009 debunked the claim back then, saying, “Biologists say it’s highly implausible that onions could attract flu virus as a bug zapper traps flies. Viruses require a living host to replicate and can’t propel themselves out of a body and across a room.”

“Onions are not especially prone to bacterial contamination,” said Dr Joe Schwarcz, director of the McGill University’s office for Science and Society.

“In fact, quite the opposite, they feature a variety of sulphur compounds that have antibacterial activity. Of course that doesn’t mean they can in any way protect against the flu which is a viral disease.”

Dr Joe Schwarcz

The message also claims that placing cut onions around will create a magnet to absorb bacteria, and to this Schwarcz said, “ a cut onion's surface dries out quickly, reducing the moisture that is needed for bacteria to multiply,” so the myth is not scientifically sound.

So to recap, the flu is a virus spread by contact not floating microbes and onion cannot absorb viruses and thus cannot prevent the flu.

Don’t Fear Onions!

Many cultures believe onions have medicinal properties and the World Health Organization too says that onions can help in relieving colds, coughs asthma, bronchitis.

Dr Schwarcz added that onions have a host of health benefits and “have been linked with a reduced risk of stomach cancer and flavonoids in onions can lower blood pressure and reduce the risk of blood clots forming.”

So as long as eaten hygienically, onions are safe and can even help in reliving the flu but cannot prevent it.

Yes, Don’t Give Your Dog Onion

Another part of the claim mentions that dogs’ stomachs cannot metabolise onions. According to PetMD, WebMD for animals, giving your dog onions can give actually them health problems.

Veterinarian Dr Ann Hohenhaus from New York’s Animal Medical Center spoke to PetMD saying, “"Any member of the Allium family – onions, garlic, leeks, and chives are the most common reported to cause toxicity – contains N-propyl disulfide. This damages the hemoglobin in their blood.”

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