In addition to shark fin soup, another China food is also famous for swallow nest soup. Swiftlet birds build their nests using their saliva, and the bird's nest is a very valuable commodity is believed to have high nutritional and therapeutic value. Many women who regularly consume it so that protein and minerals in the bird's nest can make them stay young and boost the immune system.

But despite the swiftlet nests containing enzymes, salt, and moisture content, there is no academic evidence to establish his claim. As we all know, the saliva does not contain nutrients. In addition there is an accident ever written in the American Journal of Medical Science: there was a man of Vietnam's arsenic poisoning after eating a contaminated bird's nest soup in the environment. So think twice before you sip your swiftlet bird's nest soup.