Will an Onion in the Room Stop a Cold or the Flu?

Could onions be the cure for your cold?. Adam Gault/OJO Images/Getty Images

Everyone wants a quick fix when they are sick. Not many people enjoy getting a cold, the flu or any other illness. As soon as we feel the symptoms coming on, we try to think up way to try to stop it. People will try everything from taking extra Vitamin C to over the counter cold and flu medications and many, many remedies in between.

One such "remedy" being passed around social media is to place a cut onion in the room of the person who is sick.

The claim is that onions have the ability to absorb bacteria and viruses and will actual pull the germs out of the sick person. 

For some reason, many otherwise rational people seem to believe this could be true. I'm not sure how we got to the point where ideas like this that are passed around on the internet are trusted more than health care professionals who have years of education and experience but that seems to be where we are. 

So, if you are reading this to see if cutting an onion and placing it in the room with you will stop a cold or the flu - it won't. 

Why Doesn't It Work?

The idea that a vegetable sitting in a room could absorb germs that are in a person's body doesn't even make sense. That's not how science and illness work. When you get sick, microscopic bacteria or viruses enter your body and there they are able to multiply because your body acts as a "host". When your immune system notices these invading germs, it releases antibodies to try to fight them off.

This "fight" is what causes the symptoms you experience when you get sick. If you have a cold, your body starts to make excess mucous, you may cough, have a sore throat or headache due to swelling and irritation. All of these symptoms are actually your body's way of fighting off the germs.  

It isn't scientifically possible for an onion (or any other vegetable, fruit, etc) to sit in a room and pull all of these germs out of you.

Onions contain virtually no protein and do not provide a good environment for bacteria or viruses to multiply or live. And when these germs are in your body, which does provide a good environment for them to live, they aren't going to somehow be magically "sucked out" by an onion.

Technically it won't hurt anything to try, but it isn't going to stop your cold. 

Where Did This Story Come From?

Some of the versions of this claim that I have seen refer to the use of onions to protect people from the 1918 flu pandemic. In this story one doctor's patients placed cut onions in their homes and they all stayed healthy while others in the community did not.

The doctor came upon this one farmer and to his surprise, everyone was very healthy. When the doctor asked what the farmer was doing that was different the wife replied that she had placed an unpeeled onion in a dish in the rooms of the home, (probably only two rooms back then). The doctor couldn't believe it and asked if he could have one of the onions and placed it under the microscope. She gave him one and when he did this, he did find the flu virus in the onion. It obviously absorbed the virus, therefore, keeping the family healthy.

However, versions of this theory go back to the 1500's when cut onions were placed around homes to protect inhabitants from the bubonic plague.

At the time, people believed that all illnesses were spread through the air. These clouds of disease - or miasmas - were thought to exist when the air smelled bad. In fact, this theory persisted even into the 19th century. It seems ridiculous now, but many people at the time - including physicians - resisted the idea that they should wash their hands to prevent the spread of disease because they thought illness was only spread through the air. 

If it sounds a little too good to be true - that's because it is. It's not based on science at all. 

Please, please don't believe everything you read on the internet. And if you read something that seems a bit far fetched, take a few seconds to research the answer before you hit "share". 


"Brief History During the Snow Era". Department of Epidemiology. UCLA School of Public Health. 19 Mar 15.

"Competing Theories of Cholera". Department of Epidemiology. UCLA School of Public Health. 19 Mar 15. 

"Viral Infections". MedlinePlus 3 Mar 15. US National Library of Medicine. National Institutes of Health. Department of Health and Human Services. 19 Mar 15. 

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