1. A Brief History of Dietary Chinese Herbs
Diet is important to health, not just for the nourishment of the body but also for maintaining optimal balance and thus preventing illness. In traditional Chinese medicine (TCM), food is an essential component for the prevention and treatment of many diseases. A combination of diet, herbal medicine, acupuncture and physical exercise techniques such as Tai Ji (, Tai Chi), has been an important aspect of Chinese culture related to health and wellbeing from ancient times to the present day.
To introduce the topic, the major literature is discussed in chronological order to provide an overview of the origin and development of dietary therapy or medicated food in Chinese history. The discussion of the major literature on TCM is based mainly on the studies of Chen [].
The concept of food as medicine had already been mentioned in the earliest TCM literature Huangdi Neijing (, or Emperors Inner Canon, generally accepted as having been written between 475 BCE220 CE). It was not written by a single author, although author names are unknown. It is the fundamental piece of theoretical work in Chinese medicine and includes the introduction of the principles of Yin-Yang (), Qi (, or Chi, life energy) and the Five Elements (), as well as the importance of balance in health. In addition, the interior of the body as well as the environment are both important considerations for this balance for health. Disease prevention was regarded as the preferred approach of health management, with the famous statement of the best doctor is the one who prevents diseases.
As early as in the Zhou Dynasty (c. 1122 BCE256 BCE), dietitians appeared and shared the official title of healthcare professional along with physicians, surgeons, and veterinarians. Health preservation with food () has since become an important aspect of Chinese culture and healthy living.
The earliest TCM herbal drug book, Shennong Bencao Jing (, or Shennongs Classic of Materia Medica, authors unknown), was compiled between 221 BCE220 CE. It describes 365 items (minerals, herbs, and animals) across 3 categories, the top-, middle-, and low-grades based on medicinal and safety properties. More than a hundred materials are listed in the top-grade group. The list includes recommendations on the consumption of many non-toxic items which yield a variety of health benefits.
The concept of dietary therapy ( or ) was first explicitly introduced by the prominent doctor, also known as the King of Medicine, Simiao Sun, in his book Beiji Qianjin Yaofang (, or Essential Formulas for Emergencies Worth a Thousand Pieces of Gold, 652 CE). This work contains 30 volumes, and Vol. 26 was dedicated to dietary therapy (). In the introduction section of this volume, he wrote: As a doctor, you must first check into the root of illness and understand all the affected. Treatment should start with foods, if dietary therapy not working, then medicine. It included 154 food items, such as 29 fruits, 58 vegetables, 27 grains, and 40 animal materials as well as detailed discussion on the relations of foods, internal organs and their functions, compatibility, and seasonal considerations.
In Tang Dynasty, the first book on dietary herbs, Shiliao Bencao (, or Materia Medica for Dietary Therapy by Shen Meng and Ding Zhang), was compiled in the early 8th century. It included 227 items of herbs and various foods. For each item, the health benefit property, applicability or precaution, proper harvesting time, and processing and cooking methods were discussed. The work laid the foundation for the application of dietary Chinese herbs. There was another book, Shixing Bencao (, or Edible Materia Medica, by Shiliang Chen, 937957) which also appeared around this time as an important contribution to this field.
During the Yuan Dynasty, dietary therapy and dietary herb application were further developed, as revealed in several books; two are worth mentioning. Riyong Bencao (, or Materia Medica for Daily Use, by Rui Wu, 1329), is a collection of 540 food or herb materials. It expands on the particular use of the different parts of plants. The other book, Yinshan Zhengyao (, or Principles of Correct Diet, by Sihui Hu, 1330), includes 230 food items and describes details on their properties, such as the basic cold, hot, warm, cool and moderate nature of food. For the first time, food items from northern ethnic groups, including Mongolian food materials are introduced.
Food and dietary therapy prospered in the Ming Dynasty, with the publication of a long list of important books in history. Jiuhuang Bencao (, or Materia Medica for the Relief of Famine, by Su Zhu, 1406) recorded 414 wild edible plants, including 245 whole herbs, 80 wood materials, 20 grains, 23 fruits, and 46 vegetables. Most of the plants were also grown by the author and have very detailed pictures drawn by professional painter, so it is also an important piece of literature in botany, agriculture and Chinese medicine. Shiwu Bencao (, or Food Materia Medica) published in 78 different versions by various authors within a century (15001620), contains similar contents (386 food materials, and one version with 492 color pictures of plants and plant parts). One later version of a book with the same name was compiled by Kecheng Yao (based on the work of Li Gao, Yuan Dynasty and assisted by Shizhen Li, the greatest doctor and herbalist in Chinese history). It was published in 1621 which contains 22 volumes, recorded 1679 items of water (refers to water from various sources and geographic sites or origins) and food items with 750 dedicated to water. Most of the food and herb items are based on Shizhen Lis Bencao Guangmu (, Compendium of Materia Medica, 1596), with the exception of the items related to water.
The Compendium of Materia Medica, with a description of 1892 items became the most complete and comprehensive medical book and one of the most important pieces of literature in the history of TCM. In addition to a number of dietary herbs, it contains 43 items of water for medical use, 73 grains, 105 vegetables, 127 fruits, and 444 animal related materials most of which are edible and nutritious. The work also listed more than 50 medicated porridges and about 80 tinctures (medicated liquors), as well as applications to common food cooking practices in medicinal foods or dietary herbal preparations [].
During the Qing Dynasty, dietary application of herbs in health preservation, disease prevention and treatment continued to expand. Important works include: Shiwu Bencao Huizuan (, or Collections of Food Materia Medica, by Lilong Shen, 1691), with 608 entries; Shiwu Kao (, or Food Records, by Bai Long, 1795), with 1106 entries; and Tiaoji Yinshi Bian (, or Mechanism Analysis on Medicated Food, by Mu Zhang, 1813), with 653 entries and a detailed analysis of properties and healing mechanisms of the food items.
In the past 200 years, research and the practical application of dietary therapy have grown rapidly. Searches into National Library of China for Chinese books related to (dietary therapy) and (medicated diet/food) ended in 1613 and 934 titles in the collection respectively [].