Chicken Soup Helps a Cold
"The old remedy of eating chicken soup to help you recover from a cold."
Taken seriously enough that a real pulmonologist decided to test it properly. Dr. Stephen Rennard at the University of Nebraska Medical Center studied chicken soup's effect in the lab, publishing his findings in 1993 and again in 2000. He found that chicken soup measurably inhibits the movement of neutrophils, immune cells that, in excess, drive the inflammation responsible for many cold symptoms. It's likely the combination of ingredients rather than any single one doing the work. The honest caveat is that this was a laboratory study of the soup's effect on cells, not a full clinical trial tracking real patients' recovery, so "chicken soup measurably calms inflammation" is well supported, even if "chicken soup cures your cold faster" hasn't been directly proven in patients.