There are three main lines of reasoning for arguing that food was medicinal. Firstly, food was required to maintain health. Secondly, food was used to prolong and enhance life, such in yangsheng (self-cultivation) culture. Thirdly, food was directly able to cure disease.
FOOD MAINTAINED HEALTH. Early ideas about food already recognised that it was necessary for health. Shennong, the Divine Farmer, civilised man when he taught him to transform savage, raw ingredients into edible, nutritious dishes through the art of cooking (Sabban, 2000 p.1165). Shennong was, according to the Huainanzi (2nd century BC), not only the patron saint of agriculture but also pharmacology (Unschuld, 2010 p.113). This suggests that ideas of food were intertwined with medicine from an early date. Although food and medicine could cooperate in the maintenance of health, it was often argued that food was the superior partner. Sun Simiao (581-682AD), in the first extant materia dietetica, Shizhi, (Engelhardt, 2001 p.176) argued that although medicine was useful, only food was sufficient for health:
For the human body to remain in a healthy and balanced state, nothing else is required but to care about its nourishment. By no means should drugs be consumed recklessly. ... Living beings have always depended on food to maintain their life (Unschuld, 1986 p.209). [my emphasis]
The consumption of a balanced diet, with appropriate amounts of different foods, was recognised as important for wellbeing (Unschuld, 1986 p.205). Different types of foods were thus ascribed different functions. Cereals, for example, nourished and sustained life (Sabban, 2000 p.1166). Undoubtedly, the assignment of a central role to cereals such as rice was influenced by the fact that it was already the most commonly eaten food among Chinese people (Sabban, 2000 p.1166).
As ideas about qi and systems of correspondence coalesced, they were extended to food to formalise and rationalise its healthfulness within the framework and terminology of Chinese philosophical and medical ideas. A combination of empiricism and correlative thinking allowed food to be systematically classified. From the 7th century, food items had distinct effects on the body based on their their wei (sapor) and qi (Lo & Barrett, 2005 p.397). By the 18th century, each wei (sour, bitter, sweet, pungent or salty) (Anderson, 1988 p.189) was associated with one of the wuxing and correspondingly to an organ (lungs, spleen, kidneys, liver or heart); while qi indicated the food's thermostatic qualities of hot, warm, neutral, cool or cold (Lo, 2005 p.164). It is useful to note at this point that Chinese medical historians translate wei as 'sapor' rather than 'flavour' to emphasise its medical rather than culinary and aesthetic connotations (Lo, 2005 p.164). Indeed, wei transcended mere flavour in determining the nutritional value of food. Flavourless foods, for example, could have the most qi and nourish the most remote ancestors (Lo, 2005 p.163). Yuan Mei (1716-1797) warned in his cookbook Sui yuan shi dan (Recipes from the garden of contentment) against destroying the flavour of food with elaborate seasoning (Lo, 2005 p.163) although it is uncertain whether he was more interested in the medical or aesthetic disadvantages of over-seasoning. A warning that strongly-flavoured food was ineffective in nourishing the body was also found in the more medical context of Yinshan zhengyao (Proper and essential things for the Emperor's food and drink), presented to the Mongol Emperor by Hu Sihui in 1330 (Buell & Anderson, 2000 p.261). This was a cookery text that blended Mongol food and Muslim spice in recipes grounded in the latest Chinese medical theories of the time (Buell & Anderson, 2000 p.130).
Careful balancing of the wuwei (five sapors) brought the five zang organs in harmony and maintained qi and shen (Unschuld, 1986 p.213). This was in accordance with theories underscoring the construction of the systems of correspondence that humans should strive toward the resonance of their microcosmic body with natural, macrocosmic processes (Sivin, 1995 p.26). Zhouli (Rites of the Zhou) presented the first written example of a seasonal regimen for eating. It advocated, for example, the consumption of hot food during the hot season (Unschuld, 1986 p.206). While homeopathic reasoning may not be as well-recognised in Chinese systems of correspondence as allopathic logic, it does exemplify yinyang theory, which specifies that when an extreme is reached, it transforms into its opposite (Lo, 2011b p.16). This may reflect an application of correlative thinking to empirical observations that hot food promotes sweating, which in turn cools the body. Furthermore, that dietetic physicians tasked with balancing foods according to the season in Zhouli were seen as the highest class of medical personnel (Anderson, 1988 p.187) serves to emphasise the importance of food within Chinese medical culture. Huangdi neijing (Yellow Emperor's canon of internal medicine), the sacred medical text underpinning elite Chinese medicine, was also concerned with diet and promoted a seasonal regimen for eating based on allopathic principles to maintain health (Unschuld, 2003 p.299). Chinese authors argued that eating should not be about satisfying cravings for food and drink but about nourishing qi to maintain health (Unschuld, 1986 p.213). Today, ideas about the healthfulness of food are also validated by Western medical ideas. Green tea, for example, was long believed to be beneficial and, among other things, encourage alertness and contribute to longevity; many of these claims have been validated by Western medical research (Simoons, 1991 p.447).
However, as Sun Simiao noted in his Shizhi '...even food has positive and negative aspects' (Unschuld, 1986 p.209). While it could help to maintain health, the wrong food could lead to illness. Knowledge of what foods to avoid was therefore also important to maintain health. This knowledge was available in shijin (nutritional interdictions). These were often extrapolated from almanac literature. Correspondingly, many food taboos were concerned with determining auspicious or inauspicious times, based on cosmic regularities such as the lunar cycle, to correspond the consumption of certain foods to these times (Lo, 2005 p.178-9). For example, one Qin almanac stipulated that 'When on ren and gui days there is illness... It is gotten through wine and slivers of dried and fresh meat served with vegetable and meat sauce' (Lo, 2005 p.179). Avoiding such food on the prescribed days would ensure the maintenance of health. Such interdictions also pervaded other aspects of medical literature; this highlights how food and medicine were subject to the same influences. Some food and food-drugs that should be eaten warily were described as du, a measure of not only their high medical efficacy but also their ability to poison (Lo, 2005 p.172). Some du foods were directly toxic if eaten, while others, such as uncastrated male poultry, could potentiate poisons in the body of the consumer (Anderson, 1988 p.195). Like other foods, the classification of du foods was probably based on both sympathetic resonance and empirical observation. For example, certain seafood items may have been prohibited after an allergic reaction such as hives was observed in response to its consumption (Anderson, 1988 p.195).
FOOD WAS USED TO PROLONG AND ENHANCE LIFE. In this way, food was connected to yangsheng culture. The preparation and consumption of certain foods intertwined with techniques that aimed to extend life beyond its normal lifespan, or to achieve immortality (xian). For example, Ancestor Peng, who reputedly lived for over 900 years, and his followers renounced eating grains (Lo, 2001a p.2; Harper, 1998 p.113). Yangsheng fang (Recipes for nurturing life), a text from Mawangdui , described quasi-culinary prescriptions, such as choice beef sliced thinly and thrice-cooked with yam, to lighten the body and increase qi (Harper, 1998 p. 345). One of the early handbooks on nourishing life, Zhang Zhan's (fl. 4th century) Yangsheng yaoji, recommended suitable diets for longevity based on the effect of different foods (Engelhardt, 2001 p.175). Sun Simiao explained how the sage employed food to preserve his nature and extend his life:
The five grains provide nourishment (yang), the five fruits provide support (zhu), the [meats of the] five domestic animals provide augmentation (yi), and the five vegetables provide completion (chong), thus combining qi and sapors in the diet in order to replenish the essence and to augment the qi [of the body]. (Engelhardt, 2001 p.180)
Only if food was unsuccessful did he resort to drugs to sustain life (Engelhardt, 2001 p.181). Sun Simiao's audience was unambiguously medical, further illustrating that food was placed within a medical context to serve a medical purpose. For example, Sun Simiao borrowed from Tao Hongjing's (452-536AD) pharmacological classification of drugs in the latter's Bencao jing jizhu (Annotated collection of the pharmaceutical canon) and correspondingly organised food items into three grades (Lo & Barrett, 2005 p.406-7). The highest class of foods, 'rulers', were useful in strengthening the body or promoting longevity (Unschuld, 2003 p.32). Meng Shan (621-713), the author of Buyang fang (Prescriptions to fill and nourish) and his follower Zhang Ding, who expanded Buyang fang into Shiliao bencao (Materia medica for successful cures through nutrition) in the early 8th century, were associated with Daoist circles that were concerned with longevity (Unschuld, 1986 p.208). In subsequent years, the most important passages of their works were adopted into the main bencao (pharmacological) tradition while the rest were lost (Unschuld, 1986 p.210); food was therefore increasingly integrated into the medical tradition. Yinshan zhengyao had long tracts on longevity and shijin based on concepts of magic correspondence interspersed with its recipes (Buell & Anderson, 2000 p.14; Unschuld, 1986 p.216). For example, a recipe for Golden Marrow Concentrate using Chinese matrimony vine fruits 'extends life and amplifies longevity.... If taken for a long time, white hair becomes black again. It counteracts old age and restores youth' (Buell & Anderson, 2000 p.397). Food was also seen to be useful in enhancing life outside traditional yangsheng texts. Increasing qi was perceived to be important, especially since illness could be caused by its depletion (Unschuld, 2010 p.74). Huangdi neijing held that when food of appropriate combinations of wei and qi were consumed, 'they serve to supplement the essence, and to enrich the qi' (Unschuld, 2003 p.300).
FOOD WAS THERAPEUTIC. The use of food to cure diseases was sometimes based on empirical observations and sympathetic resonance rather than established within theoretical frameworks. Although Huangdi neijing prescribed foods for certain diseases, these were not fitted into the systems of correspondence or theoretically associated with the body's conduits or physiology (Unschuld, 2003 p.294; p.296). The use of some foods as drugs may have been derived from trial and error in the kitchen (Lo, 2005 p.170). Some prescriptions in Yinshan zhengyao were based on sympathetic magic and folk believes. For example, a soup that included deer feet was believed to cure foot ache and inability to walk (Buell & Anderson, 2000 p.417). Many bu (strengthening) foods in Chinese medicine were similarly based on sympathetic magic; walnut meats have a reputation for strengthening the brain because they resemble the brain (Anderson, 1988 p.192). Theories were therefore not required to decide which drugs were effective (Harper, 1998 p.103). Indeed, even if sympathetic resonance prompted a food's use for healing, the food item may have continued to be prescribed when it was proven effective. Sheep's blood, for example, would probably have helped to relieve symptoms that would be today recognised as associated with anaemia (Buell & Anderson, 2000 p.532).
There was a gradual development of a theoretical basis for the use of food. Sun Simiao's Shizhi, by quoting from classical medical theories in the Lingshu and Suwen of the Huangdi neijing, sought to rationalise dietetics within the traditional framework of medicine (Engelhardt, 2001 p.179). Sun Simiao also linked the properties of food, such as wei and qi, to their effect in the mouth and body respectively (Unschuld, 1986 p.210). Foods with 'heating' qi, for example, were not necessarily hot but had a heating effect on the body. They could have a burning effect on the skin, like ginger, or raise body heat, probably since they were high in calories (Anderson, 1988 p.19). The systemisation of dietetics allowed medical professionals to logically adjust diets for specific illnesses. For example, fever, a 'heating' illness, was treated with cooling foods that did lower the body temperature while diarrhoea, a 'cooling' illness, was treated by withdrawing cooling foods such as water and vegetables (Anderson, 1988 p.191). Yinyang theory also pervaded Lu He's Shiwu bencao (Materia medica of nutrition) (mid-16th century). He recommended eating yin foods during illnesses since many diseases were due to the depletion of yin and correspondingly made references to whether foods were yin or yang in their description (Unschuld, 1986 pp.222-3).Yinshan zhengyao, for example, observed that foods with pungent wei such as ginger and garlic had effects on the body such as clearing mucus; correspondingly pungent foods must induce dispersion and expulsion movements in the body's lung and large intestine jingmai (channels) (Lo & Barrett, 2005 p.398). As in any Chinese medical tradition, balance and restraint was important. Huangdi neijing warned that in partaking each wei, 'Do not let [the patient] eat large quantities' since an excess could lead to illness (Unschuld, 2003 p.301). Overindulgence in sweet food, for example, damaged the flesh (Buell & Anderson, 2000 p.410).
Sun Simiao believed that dietetic drugs were superior to non-food drugs since they were effective against all afflictions, while the latter were too potent to be used safely in certain illnesses (Unschuld, 1986 p.206). The best medical professional, '...having found out the cause of the disease, he tries to cure it first by food. When food fails, then he prescribes medicine' (Unschuld, 1986 p.205). Shizhi tongshou (Treatise on dietetic methods of treatment) (12th century) similarly emphasised that 'when food is in order, the body is also in order. This constitutes the art of the best practitioners to treat illnesses... [my emphasis]' (Unschuld 1986, p.213). The distinction between 'food' and 'drug' may be difficult to discern. The variety of sub-cultures within China exacerbates this problem. Yinshen zhengyao, for example, emphasised northern dishes and included among its daily meals some food items that were only used in South China for medications (Unschuld, 1986 p.219). Class differences may also obscure the difference. For example, ginseng is called yue (medicine) but it is commonly eaten by those who can afford it (Anderson, 1988 p.193). At the same time, other texts warned 'Potent tonics as they are, ginseng... should be taken only in small doses and over long periods of time. In other words, they should be treated as medicine not as food' (Lo, 2005 p.178). However, instead of complicating the discussion this ambiguity only serves to further illustrate how ideas about food and medicine are entwined.
Such entanglement persists since food continues to be used therapeutically. In one study, Kleinman (1980 p.186) found that in 93% of illnesses, Chinese people altered their diets; this was usually the first self-medicating step taken. Therapeutic teahouses in Chengdu and Hangzhou, which started selling basic therapeutic soups with Chinese medicine, became popular tourist haunts selling exotic food items with purported medicinal effects. Today, they are usually not medically-oriented despite having staff to advise customers what to eat, but they do serve to highlight the popular association of food with medicine (Lo, 2011b p.15).
Yet dietetics and medicine were not always entwined. Firstly, there was a separate dietetics tradition that was appreciated for non-medical reasons. Secondly, medical therapy also encompassed other treatments such as acupuncture, moxibustion and pharmacology; only the the latter will be concisely outlined in the interests of brevity. Since the distinction between 'food' and 'drug' has been shown to be ambiguous, this essay will consider non-food drugs to be those preparations that are more overtly non-aesthetic and non-culinary. Finally, it may be argued that food was only seen as medicinal within the elite.
THERE WAS A DISTINCT NON-MEDICAL DIETETICS TRADITION. Cookbooks dating to Han (206BC-220AD), such as the 300 fragmented bamboo strips from the tomb of Wu Yang (d. 162BC) at Huxishan, were more concerned with refining the taste and presentation of the food than with its medical properties (Lo, 2005 p.171). The extant recipes reveal that the elite valued a varied diet with different ingredients and methods of preparation (Lo & Barrett, 2005 p.402). From the Sui period (581-618AD), cookbook collecting was a common activity for the literati (Lo, 2005 p.171). Dietetic texts were important enough to be listed in imperial bibliographical treatises. For example, the Hanshu (History of the former Han dynasty) listed only Shennong Huangdi shijin (Shennong's and Huangdi's nutritional interdictions). The number of titles about food increased to at least twenty by the Suishui (History of the Sui dynasty) (Engelhardt, 2001 p.174). Despite being classified under the medical tradition, some of the shijin, shijing (culinary classics) and shifang (culinary remedies) books were culinary-oriented cookbooks (Lo & Barrett, 2005 p.402). One example was Cui Hao's (d. 450) Cui Hao shijing, a presentation of his mother's recollections of various foods and their preparation (Engelhardt, 2001 p.174-5). The Chinese elite thus valued food for more than its medical or nutritious value. Instead, food and culinary finesse was celebrated as it was believed to demonstrate one's virtue in every sense of the word (Lo, 2005 p.168).
PHARMACOLOGY WAS NOT ALWAYS BASED ON FOOD. Wushi'er bingfang (52 Remedies) from Mawangdui combined not only food but also common herbs, excreta, ground insects and other substances in simple preparations to heal specific illnesses (Harper, 1998 p.99). According to Huang (1990) , these prescriptions could be passed off as dishes eaten at a routine meal (Engelhardt, 2001 p.173). However, I believe that since some of the preparations contained irregular material such as excreta, they were probably based on magico-religious theories and not culinary experience and thus unlikely to be widely enjoyed as food. Furthermore, they were communicated to interested readers using advanced and technical terminology (Unschuld, 2003 p.286).
One important extant pharmacological text is Su Jing's Xiuxiu bencao (Newly revised bencao) (659AD), which supplemented Bencao jing jizhu at the end of the Tang dynasty (618-907AD). This text included only a few more drugs from Indian and Arabian countries, but it became the official basis for pharmacological treatment as part of strict official Tang regulations governing the use of medicinal drugs due to heightened awareness of their dangers (Engelhardt, 2001 p.178). I believe that this regulation implies that Chinese medical professionals who followed government regulations more commonly prescribed drugs from this official text instead of relying on materia dietetica and adjusting their patients' diets. If this assumption was true, it would mean that food was sometimes marginalised from the medical tradition.
However, I believe that even these apparently distinct pharmacological texts largely drew from and contributed to materia dietetica. As mentioned, Bencao jing jizhu inspired Sun Simiao's influential classification of food by providing the framework for the medically-oriented organisation of food items. Another text that highlights this rich interdependence is Li Shizhen (1518-1593)'s Bencao gangmu, which systematically classified 1892 substances, including plants, animals and parts of the human body, based on 932 historical sources. In this text, food played an important role in an explicitly medical context. As in many other pharmacological texts, the medicinal properties of food items and the indications and prohibitions of their combinations according to the wuwei and medical potencies were discussed (Unschuld, 1986 p.152). Bencao gangmu was also significant in being a pharmacological text that emphasised culinary aesthetics. There was concern for the flavour (not necessarily wei) and texture of the medical preparations. Gerbil meat, for example, was 'extremely succulent and delicious, and crisp like suckling pig' (Lo, 2005 p.175). Indeed, Bengcao gangmu only continued a tradition of drawing from the culinary arts in pharmacological techniques (Lo, 2005 p.176). Many of the recipes in Wushi'er bingfang did use culinary methods of preparation and ingredients. This, however, does not mean that they were equivalent to food; they were clearly distinguished as medicinal remedies and not meals: 'Drink before eating or after eating as you wish...' (Harper, 1998 p.254).
FOOD WAS USUALLY USED AS MEDICINE ONLY BY THE ELITE. Before Song (960-1279AD), the contrasting habits of the rich and poor were rarely commented upon (Sabban, 2000 p.1167) and there is little understanding of the daily diet of the poor. However, it is not unreasonable to believe that they merely structured their diet around simple and cheap cereals and were rarely concerned with expensive and meticulous regimens based on seasons or systems of correspondence. This would be consistent with Chinese tradition of frugality in eating (Simoons, 1991 p.18).One reflection that medicinal dietetics was aimed at the elite may be discerned from Yinshu (Pulling book) (2nd century BC), a manual of therapeutic exercise within the yangsheng tradition favoured by mostly the elite (Harper, 1998 p.111). This already implies that the book, and consequently the seasonal dietary regimen that it specified, was written for elite society. Yinshu advocated eating more vegetables in the summer, but in the autumn, indulgence was allowed: 'In eating and drinking your fill indulge the body's desires.' Whenever the body is nourished and derives comfort from it ' this is the way of nourishment' (Lo, 2005 p.168). Indulgence, usually considered a sin so serious it could bring down a dynasty (Simoons, 1991 p.18), was tolerated as part of the enlightened gentleman's micro-management of his health regimen (Lo, 2005 p.168). Similarly, Yinshan zhengyao stated that exemplary men did not spare expense in structuring their diet (Unschuld, 1986 p.213), but the poor probably could not afford to lavish money on food. That Yinshan zhengyao was meant for the use of the Mongol Emperor himself further underscores how medicinal dietetics was probably the purview of the elite. Some drugs, such as prominent bu foods like bird's nest and shark's fin, were unusual and expensive and therefore likely to be only afforded by the elite (Simoons, 1991 p.25).
However, it is possible that while the poorer population did not rigidly structure their diet according to medico-philosophical theories, they still drew upon dietetics. For example, it has been mentioned that changing a diet is usually the first step taken in self-medication during illness. Indeed, this would have probably been a cheap way to try to treat disease. Furthermore, Wu Rui's (ca. 1330) Riyong bencao (Materia medica for daily use) was written for the larger population. It not only described everyday foods particularly suitable to preventing and curing disease, but also set this within the elite theoretical medical framework by describing properties such as qi and wei (Unschuld, 1986 p.220).
In conclusion, food and medicine in China have shared a rich relationship. It may be easy to assume, in the study of traditional Chinese medicine, that food played a subservient role compared to more renowned techniques such as acupuncture or exotic pharmaceuticals. However, while Chinese medicine is not solely based on food, dietetics has played an important role and has contributed to and drawn from medical theories. Indeed, food has enjoyed a high position in Chinese society, while the elite medical tradition has been more often viewed with disdain. To merely view food through the prism of medicine would be to ignore its wider cultural and social importance within not only Chinese medicine but also Chinese society.
