Originating > 2000 years ago, traditional Chinese medicine (TCM) is a medical system based on the philosophy that illness results from improper flow of the life force (qi). The movement of qi is restored by balancing the opposing forces of yin and yang, which manifest in the body as cold and heat, internal and external, and deficiency and excess.
Various practices are used to preserve and restore qi and thus health. Most commonly used are
Other practices include diet, massage, and meditative exercise called qi gong.
TCM often uses diagnostic categories that do not correspond to current scientific understanding of biology and illness (eg, general deficiency, excess of yin or yang).
(See also Overview of Integrative, Complementary, and Alternative Medicine.)
Evidence for Traditional Chinese Medicine
Obtaining high-quality evidence is difficult, mainly because the active ingredients in TCM herbs are not purified, are often unidentified, and may be numerous. Thus, determining the dose is difficult or impossible, and the dose may vary from one source of herbs to another. Information about bioavailability, pharmacokinetics, and pharmacodynamics is usually unavailable. Also, active ingredients may interact with each other in complex and variable ways.
Chinese herbal medicine traditionally uses formulas containing mixtures of herbs to treat various disorders. Traditional formulas can be studied as a whole, or each herb in the formula can be studied separately. One herb, used by itself, may not be as effective and may have adverse effects. Nevertheless, current conventional research favors study of single herbs to better control for variables. Another problem is the large number of herbal mixtures that could be studied.
Systematic reviews and meta-analyses of studies (most done in China) have shown evidence for efficacy of TCM for the following:
Symptoms of Tourette syndrome (1)
Chronic kidney disease, when combined with Western medicine (2)
Depression following stroke, when combined with Western medicine (3)
Possibly depression during menopause and perimenopause, when combined with acupuncture (4)
Possibly certain outcomes in COVID-19 (eg, resolution of chest imaging findings and cough), when combined with Western medicine (5)
Possibly acute gouty arthritis (6)
Possibly quality of life and symptom management in small cell lung cancer (7)
Many of these reviews had significant limitations, suggesting the need for confirmation with further prospective studies.
Studies of TCM herbs and herbal mixtures for irritable bowel syndrome have had mixed results, and reviews of these studies conclude that more rigorous studies are required.
Possible Adverse Effects
One problem with TCM is the standardization and quality control of Chinese herbs. Many are unregulated in Asia; they may be contaminated with heavy metals from polluted ground water or may be adulterated with drugs such as antibiotics or corticosteroids. Ingredients are often substituted, partly because the names of the herbs are translated incorrectly.
In herbal mixtures, adverse effects may also result from interactions between active ingredients. Interactions can also occur between TCM herbs and medications.
References
1. Wang N, Qin DD, Xie YH, et al: Traditional Chinese Medicine strategy for patients with Tourette syndrome based on clinical efficacy and safety: A meta-analysis of 47 randomized controlled trials. Biomed Res Int 6630598, 2021. doi: 10.1155/2021/6630598
2. Wang YT, Zhang RQ, Wang SF, et al: A systematic review and meta-analysis of integrated traditional Chinese medicine and Western medicine in treating glomerulosclerosis. Medicine (Baltimore) 100(7):e24799, 2021. doi: 10.1097/MD.0000000000024799
3. Zhang H, Li M, Xu T: Therapeutic effect of Chinese herbal medicines for post-stroke depression: A meta-analysis of randomized controlled trials. Medicine (Baltimore) 100(1):e24173, 2021. doi: 10.1097/MD.0000000000024173
4. Di YM, Yang L, Shergis JL, et al: Clinical evidence of Chinese medicine therapies for depression in women during perimenopause and menopause. Complement Ther Med 47:102071, 2019. doi: 10.1016/j.ctim.2019.03.019
5. Zhou LP, Wang J, Xie RH, et al: The effects of Traditional Chinese Medicine as an auxiliary treatment for COVID-19: A systematic review and meta-analysis. J Altern Complement Med 27(3):225-237, 2021. doi: 10.1089/acm.2020.0310
6. Huang X, Zhu Z, Wu G, et al: Efficacy and safety of external application of Traditional Chinese Medicine for the treatment of acute gouty arthritis: a systematic review and meta-analysis. J Tradit Chin Med 39(3):297-306, 2019. PMID: 32186001.
7. Chen S, Bao Y, Xu J, et al: Efficacy and safety of TCM combined with chemotherapy for SCLC: a systematic review and meta-analysis. J Cancer Res Clin Oncol 146(11):2913-2935, 2020. doi: 10.1007/s00432-020-03353-0
