Thanks to its juicy, sweet, and pulpy texture and exotic flavor, longan fruit, a well-known tropical succulent treat, has been one of the favorite choices of all time, from toddlers to the aged. It is also called Long Yan Rou or the flesh of Dragon’s Eye if translated in a literal way. It is named so because of its round black shiny seed and white protuberant umbilici, which look like the eyes of the legendary “Dragon”. Fresh longan fruits are so delicate and delicious that it is very difficult for you to forget it for once you have tasted it. However, very few people realize that it is also a good medicine. Actually this Asian fruit has a lot of health benefits, and sometimes can even play an important role on treating serious illness, in particular on women’s severe blood deficiency. That’s to say, it often works magic, especially in the cases of no other drugs will be effective. Attention please, the longan we are talking about here is the dried version.
What is longan fruit?
Medicinally it mainly refers to the aril of Dimocarpus longan Lour. or Euphoria Longan (Lour.) Steud., which is a plant in the family Sapindaceae. Hence, other names of it include Long Yan, Longan Aril, Arillus Longan, Longan Flesh, dragon eyes, and Gui Yuan. In China it is primarily produced in Guangdong, Fujian, Taiwan, Guangxi and other places. It is normally picked in the summer when the fruits become mature. And then it needs to get through a few more steps before the use – shell and pit removed, dried in the sun, and stored in dry place.
Longan plant is an evergreen tree, usually about 10 meters high. It has buttress root. Stout branchlets are puberulent and scattered with pale lenticels. Even pinnately compound leaf is alternate; the length of leaf with handle is from 15 to 30cm or even longer; leaflets are 4 to 5 pairs, or 3 to 6 pairs sometimes, and with small petiole that is usually no more than 5mm; blade is thin and leathery, from oblong-elliptic to oblong-lanceolate. Large inflorescence is acrogenous and axillary, with multiple branches, and densely covered with stellate hairs; pedicels are short; Sepals are nearly leathery, triangular-ovate, and about 2.5mm. Both sides are covered with brown tomentum and bundle of stellate hairs. Fruit is subglobose, drupaceous, indehiscent, 1.2 to 2.5cm in diameter, and usually brown or sometime pale yellow. Shell is slightly rough or few are with strumaes. Seeds are dark brown, bright, and completely wrapped by fleshy aril. Flowering time is from March to April and fruit season is from July to September.
Dry pulp contains 79.77% soluble fraction, 19.39% insoluble material, and 3.36% ash. Its soluble fraction contains glucose 26.91%, sucrose 0.22%, acids (mainly tartaric acid) 1.26%, and adenine, choline and other nitrogen-containing substances 6.309%. In addition, it still contains 5.6% protein, fat impurities and residual shell.
Longan fruit health benefits
Both longan fruit and lychee make a name of themselves for their unique flavor. And it is generally acknowledged that lychee is much tastier. But when it comes to medicinal properties, Li Shizhen believes that the longan is even better. Actually longan has been used for medical purpose as early as the Han Dynasty (206 BCE-220 CE).
According to modern research, fresh longan is not only sweet and refreshing in taste but also with very high nutritional value – containing abundant high carbohydrate, proteins, amino acids, vitamins B, C, calcium, phosphorus, iron, tartaric acid, adenine, etc. It cannot be denied that longan fruit advantages are enormous.
Modern pharmacological actions of longan
1. Vitamin P contained is especially helpful to the elderly since it is able to protect blood vessels and prevent the embrittling and hardening of the arteries.
2. It contains an active anti-aging ingredient. And this ingredient can inhibit the activity of flavin protease – monoamine oxidase type B (MAO-B), which is deemed to be something that makes people age. This discovery confirmed an old claim made by China’s first pharmacy monograph “Shen Nong’s Herbal Classic” – longan could help weight loss and keep people young.
3. Chinese Medicine Research Institute in Osaka Japan ever conducted an anti-cancer drug trial, in which more than 800 kinds of natural foods and medicine had been tested and the water extracts of longan were found with more than 90 percent inhibition rate on cervical cancer.
4. This fruit is rich in sugar, especially the digestible monosaccharides, which can be directly absorbed by human body. Therefore, it is a valuable tonic for the weak and postpartum women.
5. Its water extract (1:2) in vitro has inhibition on trichophyton microsporon and its decoction has inhibition on Shigella;
6. The extract of longan flesh and gecko can promote growth and enhance physical fitness. In addition, it can significantly prolong mice’s survival time in normal hypoxia and reduce mice’s mortality at low temperatures.
Selected longan fruit recipes in herbal remedies
According to the record in The Chinese Materia Medica, it is sweet in taste and warm in properties and it goes to meridians of heart, kidney, liver and spleen. Its fundamental functions include tonifying heart and spleen, replenishing qi and blood, and achieve a peaceful calm state of mind. Essential longan fruit uses and indications are heart-spleen deficiency, fright caused by insufficiency of vital energy and blood, palpitation, insomnia, forgetfulness, a sallow facial complexion due to deficiency of blood, irregular menstruation, and uterine bleeding. Suggested dosage is from 10 to 15 grams, or even 30 to 60 grams in large dosage, in decoction, soaked wine, cream, pills, and powder.
1. Gui Pi Tang from Ji Sheng Fang (Life-saving prescriptions). It is utilized together with Bai Zhu (Atractylodes Macrocephala), Fu Ling (Poria), Huang Qi (Astragalus), Suan Zao Ren (Semen Ziziphi Spinosae), Ren Shen (Ginseng), etc. for the treatment of over-analyzing, heart-spleen impairment caused by overexertion, forgetfulness, and palpitation.
2. Yu Ling Gao (Dai Shen Gao) from Sui Xi Ju Yin Shi Pu (Wang Shiwei’s Sui Xi Ju Food Recipe). It is formulated with American ginseng to make paste for greatly nourishing blood.
3. Long Yan Jiu (longan wine) from Wan Shi Jia Chao Fang (Wan’s Heirloom Prescriptions). In this recipe it is soaked with a jar of liquor in order to warmly invigorate spleen and stomach and boost the spirit.
Longan fruit side effects and contraindications
Although ripe longan fruit juice or flesh is so nutritious and delicious, try not to consume the unseasoned one or it is very likely to cause you asthma. And use it with care during pregnancy. Besides, it shouldn’t be used in the patients with phlegm-fire, food stagnation, or fluid retention inside, just in case it might lead to asthma due to phlegm blockage in the chest.