The health benefits of chicken noodle soup have been touted in Chinese medicine since ancient times. Here's a brief look at how this "yang", i.e. warming, food came to be seen as essential for nourishing people back to wellness.
A whole line of self-help books is predicated on the idea of chicken soup being good for the soul. Scientific evidence, on the other hand, shows there is some basis for the belief that chicken soup is good for clearing up chest and nasal congestion. There's scantier research establishing just why the broth has such healing properties. What we do know, is that this belief goes back several centuries, especially in cultures that practice traditional medicine.
China is a prime example of this. The fundamental source for Chinese medicine, the Huangdi Neijing (meaning, the Inner Canon/Esoteric Sculpture of the Yellow Emperor), had a reference to chicken soup's restorative properties as early as the 2nd century BC. The text identifies chicken soup as a "yang food", meaning it had warming properties when consumed. Further, the manual also advised the addition of specific herbs to the broth, depending on which ailment it was the physician was called on to treat.
Historian-geographer Juliane Schlag writes in The Conversation that while the Huangdi Neijing may offer some of the earliest recorded evidence, there is archaeological support for the possibility that people were making soup-like dishes with poultry quite soon after they discovered the process of boiling water. The broth would have been considered nourishing for new mothers, the elderly, and the infirm. These are all groups of people who would have been seen to benefit from "yang foods".
In China, chicken soup gets a popular variation in the form of chicken noodle soup. How did this pairing occur? "Lamian", one of China's oldest noodle dishes (its recipe dates to the 2nd century AD) involved pulling, twisting and folding dough by hand, until it formed long strands. Technique was everything when it came to preparing lamian.
Lamian was mainly prepared in two ways: in a soup base (tangmian) or as a stir fry (changmian). The tangmian's base was often a beef broth, but chicken became popular too, especially because of the symbolism when the two were combined. In Chinese culture, noodles represent longevity, whereas chicken soup is meant to ensure the well-being of one's kin. Thus, the dish was seen as bringing good luck.
During the Song Dynasty, noodle shops proliferated throughout the land, and chicken noodle soup became a mainstay of people's diets. As for whether or not it helped their souls, perhaps even the most astute historian would be at a loss to answer that.