Chinese Yam

Huai yam refers to the yam currently produced in Niutou Mountain, Zhongshan, Jiangsu, Anhui and other places. Its stems are usually purple-red, containing starch and protein, and are edible. It is a perennial herb with creeping stems, often purple, cylindrical tubers, opposite leaves, ovate or elliptical, milky white flowers, and dioecious plants.

As a highly nutritious food, yam contains a large amount of protein, carbohydrates, B vitamins, vitamin C, vitamin E, glucose, crude protein amino acids, bile alkali, allantoin, as well as iodine, calcium, iron, phosphorus and other inorganic salts and trace elements that are indispensable to the human body.

Morphological characteristics

Twining herbaceous vine. The tuber is long cylindrical, grows vertically, can reach more than 1 meter long, and is white when dry in cross section. The stem is usually purple-red, right-handed, and hairless. The leaves are simple, alternate in the lower part of the stem, opposite above the middle, rarely in whorls of 3 leaves; the leaves vary greatly, ovate-triangular to broadly ovate or halberd-shaped, 3-9 (-16) cm long, 2-7 (-14) cm wide, gradually pointed at the apex, deeply cordate, broadly cordate or nearly truncated at the base, and the margins are often 3 cm shallowly lobed to 3 cm deeply lobed, the middle lobe is ovate-elliptical to lanceolate, and the lateral lobes are auricular, rounded, nearly square to oblong; in seedlings, the leaves are generally broadly ovate or ovate, with a deeply cordate base. There are often bulbils in the axils of the leaves.

The efficacy and function of Chinese yam

Chinese yam is a medicine in the mountains and a medicine in food. It can not only be made into health food, but also has medicinal value for regulating diseases. "Compendium of Materia Medica" points out that Chinese yam can treat all kinds of deficiency and damage, treat five kinds of labor and seven kinds of injuries, remove wind from the head and face, stop waist pain, eliminate irritability and heat, replenish insufficient heart qi, open the heart hole, remember more things, benefit kidney qi, strengthen the spleen and stomach, stop diarrhea, moisturize fur, and can treat swelling and hard poison when pounded raw; Yuye Decoction and Zipei Decoction in "Medical Records of Chinese and Western Medicine" use Chinese yam with astragalus, which can treat thirst, asthenia and asthma. It is often combined with Chinese medicinal materials such as wolfberry and mulberry, which are both medicinal and edible, to make tea and drink, which can nourish the kidney and strengthen the body, enhance resistance, and can play a better health care effect. However, the Chinese medicinal materials market is flooded with counterfeit and inferior products, and there are problems such as dyeing, sulfur fumigation, and fake origin. Modern medical research believes that Chinese yam has the following effects:

1. The Chinese medicines for lowering blood pressure, such as Liuwei Dihuang Pills, Bawei Dihuang Pills, Guishao Dihuang Pills, etc., are all famous prescriptions made with yam. They are not only used to treat kidney deficiency, but also to treat hypertension, diabetes, asthma, neurasthenia, low back pain and other diseases.

2. Delaying aging Modern science has proven that Chinese yam can significantly reduce the activity of enzymes that accelerate the aging of organisms. Bawei Dihuang Wan, which contains Chinese yam, is mainly used to treat postpartum sweating. Baoyuan Qingjiang Decoction and Baoyuan Hanjiang Decoction can treat vomiting blood and nosebleeds; Hanlin Decoction and Gaolin Decoction can treat gonorrhea. Chinese yam can also treat tuberculosis, typhoid fever and women's diseases, which are all beneficial to longevity.

3. Anti-tumor effect Yam tubers are rich in polysaccharides, which can stimulate and regulate the human immune system. Therefore, they are often used as health care products to enhance immunity. Yam polysaccharides have an antagonistic effect on the cellular immunosuppression caused by cyclophosphamide, and can partially or completely restore the suppressed cellular immune function to normal. Yam can also enhance the phagocytic function of white blood cells. For example, Liuwei Dihuang Pills can treat chronic nephritis, hypertension, diabetes, neurasthenia and other diseases. Zhibai Dihuang Pills can treat ankylosing spondylitis and gynecological miscarriage, vaginal itching, amenorrhea and other yin deficiency and fire excess syndromes. Guishao Dihuang Pills can treat earaches, tinnitus, yin deficiency and spontaneous sweating, etc.

4. Can treat skin diseases. The allantoin contained in yam has anesthetic and analgesic effects, can promote epithelial growth, anti-inflammatory and antibacterial. It is often used to treat chapped hands and feet, ichthyosis and various keratotic skin diseases.

Nutritional value of Chinese yam

Chinese yam has been eaten by humans since ancient times and is one of the earliest plants eaten by humans. As early as the Tang Dynasty, the great poet Du Fu wrote in his poems that "Chinese yam is good for filling the intestines". Chinese yam tubers are thick and juicy, sweet, soft, and sticky, and are delicious when eaten raw or hot. According to the test results of Shandong Academy of Agricultural Sciences, the tubers contain an average of 14.48% crude protein, 3.48% crude fiber, 43.7% starch, 1.14% sugar, 2.62% potassium, 0.2% phosphorus, 0.2% calcium, 0.14% magnesium, 5.51% ash, 53.57ppm iron, 29.22ppm zinc, 10.58ppm copper, and 5.38ppm manganese. Chinese yam contains 16 of the 18 amino acids needed by humans.

The meat of Chinese yam is tender and contains extremely rich nutritional and health-care substances. The "Shennong's Herbal Classic" says that it "mainly strengthens the middle and replenishes the deficiency, removes cold and heat evil spirits, replenishes the middle and strengthens the strength, grows muscles, and makes the ears and eyes smarter after long-term use"; ((Rihuazi's Herbal Classic says that it "helps the five internal organs, activates the tendons and bones, strengthens the mind and calms the mind, and mainly treats spermatorrhea and forgetfulness"; "Compendium of Materia Medica" believes that Chinese yam can "benefit the kidney qi, strengthen the spleen and stomach, stop diarrhea, dissolve paralysis and moisturize the fur." ​​Studies in recent years have shown that Chinese yam can induce the production of interferon and enhance the body's immune function. The choline and lecithin it contains help improve people's memory. Regular consumption can strengthen the body and delay aging. It is a favorite health product. The bionic food made with Chinese yam as the main ingredient and konjac as the supplement is rich in nutrition, nourishing and fitness, and beautifying. It is a rare healthy and nutritious delicacy.

Medicinal value of Chinese yam

[Nature and flavor]: sweet, neutral in nature. Enters the spleen, lung and kidney meridians.

[Effects]: Nourishes the spleen and stomach, promotes the production of body fluids and benefits the lungs, nourishes the kidneys and astringes semen, clears away heat and detoxifies.

[Indications] Spleen deficiency, poor appetite, chronic diarrhea, lung deficiency, asthma and cough, kidney deficiency, spermatorrhea, leucorrhea, frequent urination, and thirst due to deficiency heat.

In traditional Chinese medicine, there is a saying that there are four major Huai medicines, which refer to Chinese yam, Rehmannia root, Chrysanthemum and Achyranthes bidentata produced in Huaiqing Prefecture, Henan Province (now the area near Qinyang, Henan Province). Huai refers to the place of origin, Henan, which the ancients called authentic medicinal materials (what we call authentic or the real place of origin). Therefore, Huai yam is the yam that doctors require to be taken out from Henan. Among them, "Iron Stick Yam" is a famous traditional local specialty.

However, in the 21st century, Lixian yam began to become famous in the international market, surpassing iron stick yam. In 2003, Lixian County, Hebei Province, was named "China's Yam Hometown" by the Ministry of Agriculture after an on-site review by the expert group of the Ministry of Agriculture and the Chinese Academy of Sciences, becoming one of the seven major agricultural characteristic industrial zones in the country; in 2005, Lixian yam was officially designated as a "China Geographical Indication Protected Product" by the state; on the morning of May 13, 2011, the European Union announced in Brussels that Lixian yam, Guanxi honey pomelo, Shaanxi apple, Longjing tea and other four Chinese agricultural products and Longkou vermicelli had obtained protection marks in the European Union. The geographical indication certificates of Guanxi honey pomelo, Shaanxi apple, Longjing tea and Lixian yam were handed over to Zhi Shuping, director of the General Administration of Quality Supervision, Inspection and Quarantine of China.

Side effects of Chinese yam

1. The saponins contained in the yam skin or the alkaloids contained in the mucus may cause yam allergy and itching in a few people. Direct contact should be avoided when handling yam.

2. It cannot be eaten raw, because raw yam contains certain toxins.

Contraindications of using Chinese yam

The saponins contained in the yam skin or the alkaloids contained in the mucus may cause yam allergy and itching in a few people. Direct contact should be avoided when handling yam.

This product nourishes yin and helps dampness. It is not suitable for people with dampness, fullness, stagnation, and solid evil. It also has a convergence effect, so it is not suitable for people with colds, dry stools, and gastrointestinal stagnation. It cannot be eaten raw. Pregnant women should be careful to eat it because raw yam contains certain toxins.