Raw onions do not absorb germs, stop colds, cure flu

Food and drink home remedies, like chicken soup for a cold or ginger ale for an upset stomach, are often passed down from generation to generation.

VERIFY polled readers about their families’ folk traditions, and many asked if their family’s cold cures were scientifically backed.

Several VERIFY readers, including Michele, told us about an alleged treatment for a cold or flu that involves leaving a raw, sliced ​​onion in a room. Another version retained in blog entries and YouTube videos has been claiming for the past decade that you should wear a sock with a slice of raw onion in it overnight. The onion slice is theorized to cleanse your body of diseases because they claim onions are “known air purifiers.”

How many layers of truth are there behind this popular theory?

Can raw onions, indoors or on the skin, cure a cold or flu?

No, raw onions in a room or on the skin will not cure a cold or flu.

There are several variations on this ancient folk belief, and none of them have been scientifically proven. One theory is that a raw, sliced ​​onion can pick up airborne germs or ingest pathogens. Another claims that rubbing onions on a sick person’s feet can rid that person of the germs or “detoxify” them and cure their illness. But none of this is true.

Onions do not draw pathogens out of a sick person or pick up germs from the air. You also won’t trap germs on or in your body by rubbing them on your feet.

“Onions don’t provide a good environment for bacteria or viruses to reproduce or live,” he says Very good health, a health information site whose entire content is reviewed by board-certified physicians. “Even if an onion could evade or remove germs from someone (which is scientifically impossible), there’s nothing special about an onion that would kill those organisms.”

That National Onion Association attributes the beginning of this myth to 15th-century Europe, when many people believed that placing raw, sliced ​​onions in rooms could protect the people inside from the bubonic plague. At that time, it was believed that contagious diseases spread through “harmful air” because germs had not yet been discovered.

Some people have expanded on this folk belief by combining it with an ancient Chinese folk medicine called reflexology, said Bwalya Lungu, Ph.D., professor of food science and food folklore at the University of California Davis. Lungu said that people who practiced this ancient medicinal tradition believed that the nerves in the feet were an access point to a person’s internal organs.

So if you practice this tradition and believe that onions can cleanse the air of germs, then you might think that putting an onion on your foot would similarly cleanse your body of disease.

Lungu said that while she couldn’t find any studies looking at possible benefits of onions in a sock, there are two reasons why it wouldn’t work: The first reason is that onions don’t actually have these purported air-purifying properties, and the second reason is that research shows that reflexology doesn’t work and could potentially even make infections worse.

“There is no evidence that the foot is actually an entry point and the body absorbs compounds and sends them to the internal organs,” Lungu said. “We really know how the body works, and that’s just not how it works.”

These beliefs are all based on a misunderstanding of how pathogens work. Providence Health & Services, a network of hospitals, says the most common ways of getting the flu is through contact with a sick person or by touching a surface contaminated with the flu virus and then putting your hand to your nose or mouth. These are situations, Providence points out, where raw onions in your room or on your feet, even if effective, wouldn’t help.

That said, onions still have some health benefits that can improve the way your body fights disease, just not as an air purifier. But you would have to do more than put them on your skin.

“They have benefits because they’ll help you during flu and cold season — as long as you eat them,” says Providence. “Onions are good sources of prebiotics. These compounds breed good gut bacteria, which in turn boosts the body’s immune system to help you fight off nasty flu bacteria. Prebiotics may also help you sleep better and reduce stress — both good results for preventing or recovering from disease.”