by  Jillian L. Capodice, LAc

Background

The history of food and nutrition in Traditional Chinese Medicine (TCM) goes far back throughout the dynasties and classic Chinese physicians.  For example, one of the first specialized herbal books of the Eastern Han Dynasty (25-220AD) contains tremendous detail on foods that the practitioners at that time thought were important in maintaining health (2,3).  Some foods were thought to have the ability to strengthen the system, improve health or prevent aging and included foods and herbs such as Chinese date, wolfberry, sesame, grape and lotus seed.  Other renowned doctors over the various dynasties of China continued to recommend recipes and formulas for medicinal soups, healing meats, and nourishing wines.   In the Collective Notes to the Canon of Materia Medica, Tao Hongjing gave specific attention to the special properties of foods and characterized fruits, vegetables, grains and herbs according to tastes, temperatures and healing properties (2,3).

In short, the history of nutrients, foods, herbs and wines in Chinese Medicine is vast and classic texts date back over 2500 years ago.  This article will provide a brief overview of the physiology of digestion as it relates to TCM, general nutrition strategies, modern research and basic thoughts for the clinician.

Overview Physiology of Digestion

In Traditional Chinese Medicine, the spleen, stomach and intestines constitute the main organs of the digestive system.  They are interrelated by the major and divergent meridians.  The small and large ingesting are connected to the heart and lung meridians respectively and the main functions of these organs are to govern up and down bearing, transform the essence of food, and separate the clear from the turbid.  The Liu jie zan xiang lun, Elementary questions, states:  “The spleen, stomach, small and large intestines….manage the granaries and are the seat of construction…having the ability to transform the five flavors entering and the waste leaving [the body].”  Therefore this shows how impairment of movement by the spleen can lead to digestive disturbances and moreover, how specific types of food and nutrients can nourish the organs and maintain the free flow of qi.

A second major principle of nutrition in TCM is with regard to the three major dietary irregularities, which include:

  1. Ingestion of raw, cold or unclean food
  2. Overindulgence in fatty and sweet foods and overeating
  3. Habitual consumption of liquor and hot spicy foods

These factors are thought to lead to a variety of pathologies according to TCM zang-fu pathology.  Common organs and meridians affected also include the intestines, spleen, stomach and gall bladder.  Moreover, many of the indulgences in combination with TCM pestilences/evils such as cold, heat, and dampness, contribute to various TCM pathologies.

Western Nutrition

The tenets of modern western nutrition lie in the necessity for humans to obtain nutrients, or substances that must be supplied by the diet because they are not naturally synthesized in the body or not synthesized in sufficient amounts.  In general, nutrients are provided via three main groups, protein, fat and carbohydrates.  Other important elements include water, vitamins, minerals and amino acids.

Similarly western nutrition looks at nutrition and how it can affect health and disease by assessing the breakdown parts of foods and nutrient needs with regard to energy, water, proteins, fat, carbohydrate etc.. Thus the impact of nutrition and diet are also recognized in biomedical practice and as a potentially large factor in contributing to many chronic diseases such as metabolic disorder, various cardiovascular diseases, and even some types of cancers.

Current Research on TCM and Nutrition

There is a great deal of epidemiological data that exists with regard to the frequencies of certain types of cancer and the regional diet and lifestyle.  These include data on consumption of specific dietary products such as soy or tea and some studies demonstrate that a diet high in soy (from childhood) may impact the occurrence of certain cancers including breast and prostate.  Other research has focused on regional diets and the incidence of disease with regard to the whole diet.  Examples include studies on people consuming a Mediterranean diet and subsequent reduced incidence in various cardiovascular diseases or the Japanese diet where there is a reduced risk of prostate cancer incidence versus western countries.  Finally it is important to note that as countries adapt more foods from the modern western diet, increased incidences of the diseases aforementioned including diabetes and cardiovascular disease also seem to be increasing in these populations.

With regard to the TCM diet and nutrition, interesting research that has recently been published includes studies on:

  1. The association between diet and acne using a TCM approach (5)
  2. A mathematical model to determine the yin-yang nature of fruits (6)
  3. Epidemiological principles using TCM dietary patterns (7)

The first study by Law et al (5) was a cross-sectional study that looks at the clinical severity of acne using the Global Acne Grading System and yin-yang body composition scores to determine whether certain foods or compositions affected the prevalence of acne.

Interestingly the yin and yang score data was based on the classic principles of TCM including yin/yang, interior/exterior, cold/hot, and deficiency excess.  The investigators also grouped yin characteristics such as: hypo activity, dim color, cold, pale tongue and slow, deep and feeble pulse.  The yang characteristics were categorized as: exterior, hyperactivity, bright color, hot, red tongue and superficial, rapid and forceful pulse.

The results demonstrated that there were no foods that were significant associated with the occurrence of acne overall however there was an association with consumption between groups such as the consumption of “street food” (e.g.: dim sum, fish balls) was significantly associated with the occurrence of acne in the yin versus yang group (p=0.04) and the consumption of fresh-fruit juices was associated with increased occurrence of acne in the yang group (p=0.02).   While this study demonstrated that the application of a TCM pattern approach on diet led to the detection of potential associations between diet and the incidence of acne the limitations do suggest the likelihood of a casual relationship and that additional prospective studies need to be done in order to determine and fine-tune the TCM pattern approach when assessing disease incidence.

The second study by Ni et al (6) looked at a mathematical model to determine the nature of various herbal tonics categorized as yin and yang in nature.  These investigators divided 120 rats into five diet groups including, saline, hot TCM tonic, cold TCM tonic, hot (Yang) mineral solution, and cold (Yin) mineral solution, respectively.   While I was not able to obtain details on the exact formulations, the investigators then proceeded to feed the rats the respective formulas daily for 21 days. On the last day of the experiment, the investigators assessed the tongues of rats as well as collected blood to ascertain levels of thrombocytin, thyrotrophic hormone and noradrenaline.

These results demonstrated that the yang groups trended together and that there were different ratios of minerals in the serum following administration of TCM tonics and mineral solutions.  However since I was unable to obtain the full results of the paper, the results at these points seem quite preliminary and mathematical model used to assess these parameters was not clearly understood.

Finally a study by Lee et al (7) looked at the dietary patterns within the context of TCM and existing epidemiologic data in order to obtain data to design an interventional dietary strategy for various populations.  Again these authors utilized basic principles of TCM including yin/yang, hot/cold and more modern principles including acid/alkaline on dietary habits in women.  Again since this article was not accessible, I was unable to determine all of the exact assessments however I commend the authors on the novelty of the idea of beginning to think about TCM theories and practices in populations and how they might occur for disease.

Clinical Application

For practitioners of Traditional Oriental Medicine, nutritional strategies whether TCM based, western nutrition based or other-principle based are common and patients often need guidance on diet and nutrition strategies.  At present, it is difficult to assess from an evidence-based perspective whether classic TCM diets could influence diseases or act in the treatment of any disease or condition.  However in clinical practice, using TCM tenets of nutrition along with individualization of treatment strategies for individuals with conditions that will likely benefit from nutritional interventions are feasible.  This could include many conditions such as gastrointestinal disorders, chronic metabolic conditions and even stress, anxiety and general lifestyle recommendations.   All in all my recommendation is to assess each patient individually in order to determine which nutritional approaches may work best based on both their constitution and current complaint and modify those suggestions appropriately.  Finally regardless of what nutritional strategies you employ or if the foods are native to Asia or not, the most important things for the clinician to suggest are choosing clean, uncontaminated foods when possible, selecting the least processed food, and finally encouraging patients to be in calm and enjoyable settings when preparing and eating food.

References

  1. Harrison’s Principles of Internal Medicine. 17th Edition, McGraw Hill.
  2. The Yellow Emperor’s Classic of Medicine:  A new translation of the Neijing su wen with commentary.  Ni Maoshing (Ed), 1995; Shambhala Press, Massachusetts.
  3. Chinese Dietary Therapy, Liu JiLin; Churchill Livingston.
  4. The Fundamentals of Chinese Medicine, Wiseman and Ellis.
  5. Law MP, Chuh AA, Molinari N, Lee A.  An investigation of the association between diet and occurrence of acne: a rational approach from a traditional Chinese medicine perspective. Clin Exp Dermatol. 2009 Jun 22.
  6. Ni L, Lin X, Rao P. Validation of a mathematical model for determining the Yin-Yang nature of fruits. 1: Asia Pac J Clin Nutr. 2007;16 Suppl 1:208-14.
  7. Lee MM, Shen JM. Dietary patterns using Traditional Chinese Medicine principles in epidemiological studies. Asia Pac J Clin Nutr. 2008;17 Suppl 1:79-81.