Can I Eat Radish While Taking Chinese Medicine?
Folk belief in China holds that radish neutralizes the medicinal effect, so many people have heard the saying: "Don't eat radish while taking Chinese medicine." Many have asked me about this. Is it actually appropriate to eat radish while on medication? I am writing this article to answer in detail.
TCM does indeed say not to eat radish while taking medicine, especially when the formula contains Ren Shen (ginseng), when radish is specifically listed as a forbidden food. This is because ginseng greatly supplements original qi, whereas radish "descends great qi and digests food"—the opposite of ginseng's effect.
Why did the ancients say radish "descends great qi and digests food"? I believe we have all noticed that after eating radish, urination increases and a overstuffed stomach digests quickly. Modern research also shows that radish indeed promotes digestion and diuresis.
We know that in the past most Chinese medicines were taken as decoctions. If you eat radish at the same time as taking Chinese medicine, it speeds up the metabolism and excretion of the herbs, reducing efficacy. This is especially true of qi-tonifying drugs like ginseng, whose effect is directly opposed to that of radish; eating the two together cancels them out.
However, the natural metabolism of drugs in the body is generally essentially complete within two hours. So if the interval between taking the medicine and eating radish exceeds two hours, even eating ginseng and radish on the same day makes little difference.
Moreover, radish is not without benefit in treating disease. Patients with abdominal bloating and ascites should eat more diuretic foods such as radish, winter melon, pumpkin, bottle gourd and Job's tears, in order to enhance the therapeutic effect. The spleen-fortifying and bloat-relieving herbs commonly used in TCM rely precisely on their diuretic action.
Modern pharmacological research shows that Bai Zhu (Atractylodis Macrocephalae Rhizoma), Fu Ling (Poria), Yi Yi Ren (Coicis Semen), Zhu Ling (Polyporus), Dong Gua Pi (Benincasae Exocarp), Che Qian Zi (Plantaginis Semen), Niu Xi (Cyathulae Achyranthis Bidentatae Radix) and others are all diuretic Chinese herbs. We use these diuretics in treating pleural, peritoneal and pelvic effusions, so that patients excrete the fluid through increased urination.
Therefore, careful doctors may, when prescribing such formulas, also urge patients to eat more radish, winter melon and similar foods. This seems to conflict with the folk saying that radish should be avoided on Chinese medicine. Patients should not be guided by the proverb; they should follow the doctor's orders. For some patients, we even recommend long-term dietary therapy such as radish stewed with fish to relieve symptoms.
Does this mean radish is absolutely forbidden when taking ginseng? Not at all. Sometimes ginseng and radish must even be used together.
There is a Chinese herb called Lai Fu Zi (Raphani Semen), which is the seed of the radish. Lai Fu Zi is a TCM digestive and anti-retention herb; it promotes digestion and removes food stagnation, descends qi and resolves phlegm. It is indicated for food stagnation with qi obstruction, epigastric and abdominal fullness, diarrhea, tenesmus after dysentery, cough with copious sputum, and counterflow qi with panting. In fact, it also treats hypertension and pleural, peritoneal and pelvic effusions. Some veteran TCM doctors treat ascites and similar conditions by decocting 100 g or more of Lai Fu Zi alone, with definite effect. Lai Fu Zi tablets, or a tea brewed from it, can lower blood pressure.
For patients who are weak and need ginseng to greatly supplement original qi, yet also suffer from indigestion, abdominal bloating and ascites, using ginseng together with Lai Fu Zi and radish is even more effective. Hence the ancients also said, "Ginseng paired with Lai Fu Zi shows even more miraculous power." Lai Fu Zi works like radish but does not taste as good. During radish season, patients who need Lai Fu Zi can simply use fresh radish instead. So taking ginseng does not by itself make radish a forbidden food.
Radish is an excellent vegetable, very beneficial to health. The proverb also says, "When radish comes to market, doctors have nothing to do," and that "radish and cabbage keep you safe." Radish lowers blood pressure, blood lipids and blood sugar; it is truly a fine food. If the Chinese medicine being taken has no specific radish contraindication, I generally do not tell patients to avoid radish; instead I advise them to take it two hours apart from the medicine.
In summary, whether to avoid radish while taking Chinese medicine depends on the patient's specific situation. If the doctor says to avoid it, or urges you to eat more radish, follow the doctor's orders—do not be bound by custom.