When east meets west: the relationship between yin-yang and antioxidation-oxidation.

Ancient traditional Chinese medicine (TCM) has effectively relied on the theory of yin-yang balance in diagnoses and treatments of diseases and disorders for more than 2000 years. However, in eastern society, yin-yang is regarded as an incomprehensible ideology without definite physical meaning. Consequently, the yin-yang balance in medicine has not been studied by modern scientific means. In the western world, yin-yang balance is often misunderstood as a religious belief or a principle of lifestyle. Herein, we attempted to define the physical meaning of yin-yang in TCM by correlating it with biochemical processes. We propose that yin-yang balance is antioxidation-oxidation balance with yin representing antioxidation and yang as oxidation. Our proposal is partially supported by the fact that the yin-tonic traditional Chinese herbs have, on average, about six times more antioxidant activity and polyphenolic contents than the yang-tonic herbs. Our hypothesis opens an avenue to systematically study the yin-yang balance and its health implications with the use of modern biochemical tools.