The folk tradition is one of ancient Chinese reflexology. It was present before the germ theory of illness which is widely accepted today by scientists. The informant is a 79-year-old woman of Chinese and Latin descent who recalled hearing and practicing this by the instruction of her grandmother when she was young. She said that she used to believe that it worked very well when she was younger, but now feels that it was most likely a placebo effect from confirmation bias by those around her.
This medicinal folk practice states that if a person develops a cold, they should stuff their socks with onions. It is believed that the onions will help cure the illness and the person that is suffering from the cold will regain health very quickly after the treatment.
Onions have been known today to have numerous health benefits that are backed by science. However, curing a cold is not one of them. Chinese reflexology believed that disease spread through “noxious air”. Based on this, putting a powerful smelling agent such as onions next to someone’s feet, it was believed that since the onions removed the bad smell from the feet that it was curing the person of the cold or illness that they were suffering from.
This folk tradition is a great example of correlation versus causation. Chinese reflexology noticed that people with illness tended to have poorly smelling feet. They also noticed that onions had a strong scent and the ability to remove this foul smell from a person’s feet who was suffering from illness. Therefore, they believed that the onions removing the smell meant that they were curing the subject of their illness. As a passive bearer with an etic perspective on this medicinal folk tradition, it was interesting to hear the informant discuss how common this practice was among her family when she was growing up. This practice was something that her grandmother learned from her mother and had been passed down in their family as a cold remedy for generations.
For another version, see Rose Wilson Ph.D., November 28. 2017, Does an onion in the sock work for a cold?