Ancient Chinese medicine classics recorded many herb-herb interactions, precautions, and contraindications in the application of herbs. Foods may interact with herbs and there are precautions and contraindications in food intake while taking herbs.
In traditional Chinese medicine, each herb has its own properties, including the energies, tastes and actions of the herbs. It is crucial to understand these features of herbs before using them. Incorrect applications of herbs may cause serious results and adverse effects. Herbs are safe and efficacious only when they are used correctly.
For instance, ephedra (“Mahuang” in Chinese) has a taste of pungent-spicy with a warm property, and can induce sweating. It can be used to treat chills and absence of sweating in common cold caused by exogenous wind and cold factors. However, it is contraindicated in patients with deficiency and should not be used by those with spontaneous sweating, insomnia, or hypertension. In Chinese medicine, it is not used for weight loss or daily supplements at all. This may be why it caused so many problems in the West because it was used incorrectly for obesity.
Ancient Chinese medicine classics recorded many herb-herb interactions, precautions, and contraindications in the application of herbs. These include “the eighteen incompatible medicinal herbs,” and “the nineteen mutual-restraining medicinal herbs.” For example, aconite root (“Wutou” in Chinese) cannot be used together with pinellia tuber (“Banxia” in Chinese). Licorice is incompatible with seaweed. Cloves cannot be used together with curcuma root.
Because some herbs may disturb the qi of a fetus, they are contraindicated for pregnant women. These herbs include pharbitis seed (“Qianniuzi” in Chinese), knoxia root (“Daji” in Chinese), and burreed tuber (“Sanleng” in Chinese). Other herbs, such as pungent-spicy herbs that can remove blood stasis, including peach seed (“Taoren” in Chinese) and safflower (“Honghua” in Chinese), should be used with caution during pregnancy. Usually they should be avoided if their usages are not extremely necessary.
Foods may interact with herbs and there are precautions and contraindications in food intake while taking herbs. A general rule is not to eat raw, cold, greasy, hard to digest, or strong smelling foods while taking herbal medicines. Certain foods should not be taken for certain disease conditions. For example, uncooked or cold foods should be avoided by those with cold syndromes. Patients with dizziness, insomnia, and short temper should avoid pepper, wine, or garlic. Those with itching skin should avoid shrimps and crabs.
The historical medical literature also recorded that fleeceflower root (“Heshouwu” in Chinese) should not be taken together with onion, garlic, or radish. Poria (“Fuling” in Chinese) should not be used together with vinegar. Honey has antagonistic effects to raw scallion, so they are not to be used together.