Chinese yam, also known as yam, is a perennial creeping herb belonging to the Dioscoreaceae family. Its rhizome is an important member of traditional Chinese medicine. Chinese yam is sweet and mild in nature, and enters the spleen, lung, and kidney meridians. It has the effects of replenishing qi and nourishing yin, nourishing the spleen, lungs, and kidneys, and consolidating essence and stopping leukorrhea.
There are many varieties of yam. According to reports, among the nearly 600 varieties of yam, only about one-tenth are edible and medicinal, mainly cultivated domestic yam and field potato. Traditional doctors believe that the yam varieties in Huaiqing and Xinxiang, Henan, China, are of superior quality. Huaishan refers specifically to the yam produced in the Huaihe River region, also known as genuine Huaishan, and the medicinal value and tonic effect of Huaishan are slightly better than yam.
Chinese yam (Huai shan) in traditional Chinese medicine
The earliest Chinese medicine book, Shennong Bencao Jing, states: “It can replenish the weak and the emaciated, remove the evil cold and heat, replenish the middle and strengthen the body, grow muscles, and improve hearing and vision after long-term use.” Later, Chinese medicine literature also stated that yam can treat abdominal distension, diarrhea, back pain, frequent urination, spermatorrhea, forgetfulness, etc. The Compendium of Materia Medica summarizes that yam has the effects of “ benefiting the kidney qi, strengthening the spleen and stomach, stopping diarrhea, resolving phlegm and saliva, and moisturizing the skin and fur .”
Chinese yam not only has health-care and medical effects on the human body alone, but can also be combined with other medicines to form different prescriptions for the treatment of many diseases. Famous ones in history, such as the "Jinkui Shenqi Pills" (Jinkui Yaolue) for warming and tonifying kidney yang; the "Liuwei Dihuang Pills" (Xiaoer Yaozheng Zhijue) for nourishing the liver and kidneys; the "Shenling Baizhu Powder" (Heji Jufang) for replenishing qi, strengthening the spleen, removing dampness and harmonizing the stomach; the "Suquan Pills" (Annotated Furen Liangfang) for treating frequent urination, inurination and spermatorrhea; as well as the "Yuye Decoction", "Qiju Dihuang Pills" and "Zhibai Dihuang Pills", etc., all contain yam.
Yam is often used to treat diarrhea due to spleen deficiency, cough due to fatigue, forgetfulness and fever, spermatorrhea and leucorrhea, frequent urination, nocturia, sweating, diabetes, and leucorrhea in women.
The efficacy and modern research of Chinese yam (Huai shan)
Modern scientific experimental analysis shows that yam tubers contain diosgenin, mucus, pectin, choline, starch, protein, dopamine, polyphenol oxidase, fiber, and several vitamins, minerals, and trace elements. Yam is called "food of gods", which is related to its special ingredient diosgenin . In addition, yam also contains mucus, choline, glycoprotein, syringin, polyphenol oxidase and starch enzyme, yam polysaccharide, allantoin, various amino acids and dopamine hydrochloride and many other nutrients.
Dioscin has antioxidant effects, inhibits tumor cells, improves blood lipid concentration, and can promote the synthesis of endocrine hormones, forming the effect of "tonifying the kidney and nourishing yin" as described in traditional Chinese medicine. Proper intake of yam can relieve various symptoms and discomforts of menopausal women, including hot flashes, insomnia, palpitations, and bad mood.
Some scholars believe that diosgenin is a precursor to the synthesis of female hormones, which has the effects of nourishing yin and yang and enhancing metabolism ; mucin can prevent cardiovascular fat deposition and atherosclerosis, and also reduce subcutaneous fat deposition; dopamine can dilate blood vessels and improve blood circulation; yam pectin is a substance that induces interferon, which can increase the activity of T lymphocytes, enhance the phagocytic function of the reticuloendothelial system, enhance immunity, and inhibit tumor cell proliferation ; the soluble fiber contained in yam can delay the emptying of food in the stomach, thereby controlling the rise in blood sugar after a meal .
Yam is high in potassium and low in sodium, rich in dietary fiber and beneficial for digestion. It is also rich in vitamins such as vitamin B1 and vitamin B2, especially the powerful antioxidant vitamin C, which can enhance immunity. It also contains a variety of minerals: high in potassium and manganese , which are important for supporting bone health, growth, metabolism and heart function; the copper it contains is essential for the production of red blood cells and the absorption of iron.
In addition, the trace element selenium contained in yam is also helpful in preventing cancer. Using yam as a dietary therapy to nourish the human body is neither hot nor dry, and has a mild effect. It is very beneficial for those who are weak after surgery or illness, and those who have received chemotherapy or radiotherapy and have reduced body resistance, to eat yam as an adjunct to drug treatment.
In summary, it has the following 7 health benefits for the body:
Protect cardiovascular system : Yam is a standard high-potassium, low-sodium food, which can help sodium ions be excreted from the body, stabilize blood pressure, and maintain cardiovascular system;
Control blood sugar : Yam contains magnesium, zinc, vitamin B1, vitamin B2, etc., which can promote glucose metabolism in the blood; soluble fiber can delay the emptying of food in the stomach, and mucus protein will cover the food in the intestines, so that sugar is slowly absorbed and inhibit the rapid rise of blood sugar.
Anti-cancer : Yam contains 9 kinds of amino acids that the human body cannot produce, which can renew cells, metabolize bad cells, and reduce the rate of cell mutation. The plant hormones it contains can maintain normal tissue function and make cells less likely to become cancerous. The high iodine content can prevent thyroid cancer, breast cancer, and ovarian cancer.
Enhance brain function : Dioscin can promote neuron growth, enhance memory and brain function.
Relieve menopausal symptoms : Dioscin is similar to human estrogen, which helps regulate female secretions, relieve postmenopausal symptoms, prevent breast cancer and cervical cancer, and improve bone density to prevent osteoporosis.
Weight loss : The calories of yam are only 85 kcal per 100 grams, less than half of white rice (183 kcal). It is rich in dietary fiber, easy to make you feel full, and can serve as a staple food.
Good for the stomach and intestines : Resistant starch increases digestive enzymes, helps break down food, and increases beneficial intestinal bacteria; mucin can also repair the gastric mucosa and prevent ulcers.
Taboos of Chinese yam (yam) : There are 3 kinds of food that should not be eaten together
Chinese yam has astringent and antidiarrheal effects, and has a high starch content. Therefore, one of the side effects of Chinese yam is that it can easily lead to dry stools. People with constipation symptoms, gastrointestinal discomfort or indigestion should not eat it for a long time. Chinese yam is sweet and mild in nature. It is not easy to get angry if you take it for a long time or take it in large quantities. However, there are some foods that are not suitable for eating with Chinese yam:
Vegetables and fruits rich in enzymes : such as carrots, cucumbers, pumpkins, etc., if eaten with yam, the decomposition enzymes contained in them may cause the vitamin C in the yam to be destroyed, thereby reducing the nutritional value.
Pig liver containing metal ions : Pig liver contains metal ions such as copper, iron, and zinc, which can easily accelerate the oxidation of vitamin C and reduce the nutritional value of yam.
Alkaline drugs : When yam is taken together with alkaline drugs (such as stomach medicine), the alkaline drugs may inactivate the amylase in the yam, thereby reducing the nutritional value of the yam.
In addition, there is a rumor on the Internet that "yam cannot be eaten with seafood" because yam contains tannic acid, which easily combines with the ingredients contained in seafood to form indigestible tannic acid protein, thus causing nausea, vomiting, and abdominal pain. Although there is no medical evidence to prove the rumor of yam's side effects, it is recommended that people who are allergic to seafood, have a bad stomach or indigestion should be more careful before eating yam.
How to store and process yam
The storage method of yam varies slightly depending on the variety and state. For a whole yam, just wrap it with newspaper and store it in a cool and ventilated place. The shelf life of yam can be as long as 2 to 3 months . If it has been cut, since yam is rich in iron and easily oxidized and discolored, you can put it in ice water or salt water, blow it with a hair dryer until it is slightly dry, wrap it with plastic wrap or a sealed bag, and store it in the refrigerator.
If you buy a large amount of yam and cannot eat it all in a short period of time, you can peel the yam, cut it into pieces, shred it or grind it into a paste, put it in a fresh-keeping bag, and then put it in the freezer. When you need to cook, take it out and cook it directly without thawing it. Not only does it still taste good, it is also very convenient to use.
When handling yam, the yam skin contains alkaloids, which may make your hands itchy if they come into direct contact with the skin. Therefore, you can wear gloves, or soak the yam in boiling water and heat it in a microwave to denature the protein, then take out the yam and put it in cold water to peel it. This way it will be less itchy.
Conclusion
Chinese yam, a food known as "food of gods", not only plays an important role in traditional Chinese medicine, but also shows its many health benefits in modern medicine. From ancient times to the present, the nutritional value and medicinal effects of Chinese yam have been praised by people. Whether as a food or a medicine, Chinese yam can bring many benefits to our body. However, while enjoying Chinese yam, we should also pay attention to its taboos and preservation methods to ensure that its nutritional value is not lost. I hope this article can give everyone a deeper understanding of Chinese yam and make better use of this magical ingredient in daily life.
