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

There is something to be said for certain home remedies for colds. Placing a cut onion in the room of someone who is sick is one suggested "remedy" that has been passed down in some families and even over social media every cold and flu season.

The idea is that onions have the ability to absorb bacteria and viruses and will actually "pull the germs out" of the sick person. There is no truth to any of these claims. The National Onion Association, in fact, has said that there is no scientific evidence that a cut raw onion absorbs germs or rids the air of toxins/poisons. 

Why It Doesn't Work

Onions do not provide a good environment for bacteria or viruses to multiply or live. Even if an onion could draw or extract germs from someone (which is scientifically impossible), there's nothing special about an onion that would kill these pathogens.

Your body, on the other hand, is an attractive environment for bacteria and viruses—at least at first. When you get sick, microscopic bacteria or viruses enter your body and multiply; your body acts as a "host".

When your immune system notices these invading germs, it releases antibodies to try to fight them off, which prompts swelling and inflammation. This is what causes the symptoms you experience when you get sick, such as excess mucus, cough, sore throat, and headache.  It's also what's needed to help you get on the road to feeling better and beating an infection.

Where This Idea Originated

The folk remedy to keep raw onions in the room when you are sick dates back to the 1500s, according to the National Onion Association. During the bubonic plague, cut onions were placed around homes to keep people from contracting the deadly illness.

At the time, it was 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 more recent history, people used cut onions in a room in an attempt to protect against the 1918 flu pandemic. In one anecdote, a doctor had his patients place cut onions in their homes and they all stayed healthy, while others in the community did not.

A Word From Verywell

Placing an onion in the room will not treat or prevent you from getting a cold. Washing your hands regularly, avoiding crowds during flu season, and taking care of your health by eating well, exercising, and getting ample sleep can help you stay healthy.

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Article Sources
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  1. National Onion Association. Onions & Flu.

  2. U.S. National Library of Medicine. National Institutes of Health. Department of Health and Human Services. Viral Infections.

  3. Department of Epidemiology. UCLA School of Public Health. Competing Theories of Cholera.