The Anticancer Effects of Ginger
Ginger is an ingredient familiar to every one of us; it is the dried rhizome of Zingiber officinale, a perennial monocotyledonous herb of the Zingiberaceae family, Zingiber genus. Ginger was used as medicine in traditional Chinese medicine at a very early date. The ginger commonly used in TCM clinical practice is divided into fresh ginger (Shengjiang) and dried ginger (Ganjiang). Fresh ginger is the vegetable ginger we buy in the market; dried ginger is made by sun-drying fresh ginger, and dried ginger is much more pungent than fresh ginger. Fresh ginger has little irritating effect on the stomach, whereas dried ginger has a strong irritating effect. Besides fresh and dried ginger, TCM also commonly uses blast-fried ginger (Paojiang), which is made by stir-frying dried ginger together with hot sand.
Traditional Chinese medicine holds that fresh ginger is pungent in flavor and slightly warm in nature, entering the lung and spleen channels. It has the actions of sweating to release the exterior, warming the middle to stop vomiting, and warming the lung to stop cough. It is indicated for wind-cold exterior patterns, stomach-cold vomiting, and cold-phlegm cough. Fresh ginger can also reduce or neutralize the toxicity of fish and crab, Pinellia (Banxia), aconite (Fuzi), monkshood (Wutou), and Arisaema (Tiannanxing). Hence many toxic drugs in Chinese materia medica are also processed with ginger.
Dried ginger is pungent and hot in flavor, entering the spleen, stomach, heart, and lung channels. It has the actions of warming the middle, returning yang, and warming the lung to resolve retained fluid, and is used for cold pain in the epigastrium and abdomen, vomiting and diarrhea due to internal cold, and patterns of desertion of yang; it can also treat cough and wheezing due to cold retained fluid. Dried ginger is generally the dried rhizome of aged fresh ginger; it is pungent and strongly irritating, and some patients cannot tolerate it.
In addition, ginger peel and ginger juice can also be used as medicine. Ginger peel is the outer skin of the ginger rhizome; TCM holds that it is pungent in flavor and cool in nature, and has the action of promoting urination to reduce edema while harmonizing the middle. It can be used to treat edema and difficult urination. I once saw an old TCM physician in my hometown make pills from ginger peel together with jujube to treat ascites due to liver cirrhosis, and it also had good efficacy.
Ginger juice is made by washing fresh ginger, mashing it, and pressing out the juice for use. Ginger juice is pungent in flavor and slightly warm in nature. It has a strong dispersing action and the effect of opening phlegm and stopping vomiting; it can treat incessant vomiting and syncope due to phlegm-saliva. The usual oral dose is 3-10 drops, taken mixed with water or administered by nasal feeding; apply an appropriate amount externally.
For patients with a sensitive stomach who cannot tolerate fresh ginger, baked ginger (Weijiang) can also be used. Baked ginger is made by washing fresh ginger, wrapping it in paper, moistening the paper in clean water, and then baking it near a fire. This baked ginger is not as dispersing as fresh ginger, but its effect of warming the middle and stopping vomiting is stronger, and it is less irritating to the stomach, making it suitable for patients who cannot tolerate fresh ginger.
Regarding the various preparations of ginger, predecessors have the saying that "fresh ginger moves but does not guard; dried ginger can both move and guard; blast-fried ginger guards but does not move."
Modern pharmacological research shows that both fresh and dried ginger have certain anticancer effects. 6-Gingerol in dried ginger has an inhibitory effect on human myelocytic leukemia. Studies have found that 6-gingerol and 6-shogaol inhibit the survival and DNA synthesis of human myelocytic leukemia HL-60 cells; their cytotoxicity and mechanism of inhibiting tumor proliferation are related to the promotion of apoptosis.
Zingerone in dried ginger also has a good preventive effect on skin cancer and colon cancer. Zingerone acts to treat and prevent cancer by inhibiting the expression of NF-kB and other related genes induced by carcinogens. In addition, beta-elemene, a new antitumor component extracted from ginger by Chinese scholars, also has an inhibitory effect on non-small cell lung cancer; its mechanism is to mediate apoptosis through the release of cytochrome C from mitochondria.
Animal experiments show that dried ginger extract has anticancer effects during both the initiation and post-initiation stages of colon cancer induced by dimethylbenzene in Wistar rats. When dried ginger powder was administered to rats, the number of tumors in the experimental rats decreased, the incidence fell, and lipid peroxidation was weakened.
Fresh ginger has also been confirmed to have antitumor effects. Fresh ginger homogenate was sequentially fractionated and extracted with 70%-95% ethanol, the ethanol was recovered, and water was added to make each milliliter contain 2 g of crude drug. Tumor-bearing mice (HepA tumor mice) were gavaged with 10 g/kg for 12 consecutive days. The results showed that the fresh ginger alcohol extract significantly raised the organ index and the phagocytic rate of macrophages in tumor-bearing mice, markedly increased IgM content, and enhanced the transforming function of T lymphocytes. This indicates that the alcohol extract of fresh ginger can improve the nonspecific and specific immune dysfunction caused in animals by bearing tumors, and has the effect of preventing and treating tumors.
Ginger has also been confirmed to have other effects. For example, ginger can inhibit the activation of human monocytes induced by various pro-inflammatory substances, thereby reducing the expression of inflammation-related genes, and thus preventing the occurrence of neurodegenerative diseases and slowing their progression. Ginger extract also has a good therapeutic effect on atherosclerosis; it can treat hypertension and tachycardia, lower cholesterol, and improve local blood circulation, as well as being antimicrobial, anti-allergic, antioxidant, anti-motion-sickness, and antiemetic.
As a food-medicine dual-use ingredient, ginger has very low toxicity. Only some patients are intolerant to ginger and cannot use it; for most people eating ginger is no problem. However, ginger is not effective against every kind of cancer, so one must not superstitiously believe the claim that ginger can cure all cancers.