designs of randomized controlled trials not based on Chinese medicine theory are improper

Current biomedical research methods to evaluate the efficacy of Chinese medicine interventions are often conceptually incompatible with the theory and clinical practice of Chinese medicine. In this commentary, we (1) highlight the theory and principles underlying Chinese medicine clinical practice; (2) use ginseng as an example to describe clinical indications in Chinese medicine; (3) propose a framework guided by Chinese medicine theory for the evaluation of study designs in Chinese medicine research; and (4) evaluate 19 randomized, double-blind, placebo-controlled trials of ginseng. Our analysis indicates that all 19 trials with both positive and negative results confirm the specific effects of ginseng indicated by Chinese medicine theory. Study designs guided by Chinese medicine theory are necessary to validate and improve future randomized controlled clinical trials in Chinese medicine. Background Chinese medicine remains popular in China where traditional herbal preparations are estimated to account for 30-50% of the total medicinal consumption [1]. Chinese medicine has also been gaining popularity in the West [1-3]. However, Chinese medicine lacks funding and leading scientists to conduct scientific research (e.g. randomized controlled trials) [4]. The study of ginseng provides an example of the research challenges in Chinese medicine. Highly valued in the Chinese medicine classics and widely used in China for more than two thousand years, ginseng has yet to prove its safety and efficacy through clinical trials [5, 6], which, many investigators believe, may be attributed to a paradigm conflict and the poor quality of some clinical trials [7, 8]. We found that this paradigm conflict may be resolved by using study designs guided by Chinese medicine theory. Chinese medicine theory Chinese medicine is a syndrome-oriented holistic medical system that is conceptually distinct from its Western counterpart. According to Chinese medicine theory, a syndrome is a group of associated signs and symptoms described in terms of Yin and Yang, Qi, and Xue (blood) [9]. All illnesses fall into eight principal categories used to guide the prevention and treatment of illnesses [10]. These categories are Yin and Yang, Biao (exterior) and Li (interior), Han (coldness) and Re (heat), and Xu (deficiency) and Shi (excess). Western medicine, however, views a disease or syndrome as pathological changes of specific biological processes [1]. As a result, the syndromes in Chinese medicine do not always correspond with Western classifications of diseases and syndromes. For instance, hypertension may be related to syndromes of Gan (liver) Yang ascending, Yin deficiency of liver and kidney, flaming liver fire, stagnation of phlegm, Xue stasis and/or dual Yin/Yang deficiency [11]. Conversely, Qi-deficiency syndrome is related to chronic obstructive pulmonary disease [12], lung cancer [13], coronary heart disease [14] and persistent allergic rhinitis [15]. Herbal medications In Chinese medicine, medicinal herbs are categorized according to the concepts of Yin, Yang, Qi, Xue, Jing (essence) and Jin (body fluid) [16]. In general, ‘tonics’ are used to treat deficiency and ‘clear-ups’ are used to treat excess [9]. Considered the premium Qi-tonifying herb to treat various illnesses [16], ginseng is thought to have the major indications as follows: (1) Impalpable pulse caused by severe Qi-deficiency; (2) Shortness of breath, feeble voice, spontaneous sweating and a weak pulse caused by Fei (lung) Qi-deficiency; (3) Fatigue, anorexia and loose bowels caused by Pi (spleen) Qi-deficiency; (4) Fever and strong thirst caused by Qi-deficiency; (5) Palpitation, insomnia and forgetfulness caused by dual deficiency of Qi and Xue. Study design compatible with Chinese medicine theory Research topics Instead of evaluating the efficacy of ginseng in all patients suffering from a single disease, researchers should focus on those patients with Qi-deficiency syndrome. Qideficiency causes decreased visceral functions and lowered immune resistance, leading to various diseases. The manifestations of Qi-deficiency include lassitude, shortness of breath, feeble voice, dizziness, spontaneous perspiration, susceptibility to cold, pale tongue and weak pulse [10]. Participants Chinese medicine practitioners prescribe herbal medications to rectify disharmony in a patient’s system [16]. Healthy individuals should not participate in treatment groups in Chinese medicine studies. This explains the negative results from the ginseng studies in which healthy individuals participated [17-21]. Ginseng is a Qi-tonifying herb to treat five major syndromes [16] caused by Qideficiency. Therefore, we argue that only studies in which participants are diagnosed with Qi-deficiency are valid to evaluate ginseng’s efficacy [22-25].