I have been asked how yinyang wuxing fits into the idea that eating the organs of an animal may benefit the corresponding organ of our own bodies, for example how would eating the liver of a sheep help our own liver.
In the theory of yinyang wuxing, all existence is of yin and yang, and without exception yinyang transformation creates wuxing. Therefore, animal and human organs are different forms of wood, fire, soil, metal and water. Kidney is a form of water, liver is a form of wood, heart is a form of fire, spleen is a form of soil, lung is a form of metal, not because organs are have the same chemical components as wood, fire, soil, metal and water, but that they have the same yinyang nature of wood, fire, soil, metal, and water, which I have discussed in my book Yinyang Wuxing Spirit Body & Healing.
Therefore, if one has a kidney heat problem, in other words kidney yang damage, we look for food that can warm kidney water. If one has kidney water dryness, that is kidney yin damage, we look for food that can increase kidney water.
The kidney of any animal, whether sheep or cow, would have the equivalent yin and yang of the human kidney, so it can consolidate the yinyang nature of the human kidney. But eating a sheep kidney won’t fix a kidney illness, because a kidney illness is damage of either yin or yang, and needs strong yin or yang herbs to correct the disordered yinyang of the kidney, and the animal kidney would be too mild to fix the problem. Since the kidney of a sheep or cow is by nature evenly balanced in terms of yin and yang of water, this won’t alleviate a condition of yin or yang damage of water, because it won’t provide the extra yin or yang that is needed.
On the other hand, for a healthy kidney condition, consuming the kidney of a sheep, pig or cow would certainly help maintain the normal yinyang order in a person.