Driving on Highway 50, the only highway on the island of Kauai, during morning traffic, a sign advertising fresh Longan berries next to an improvised roadside fruit stand (Euphoria longana) caught my eye. I simply couldn't resist the opportunity to stop and see if these were the very same as the dried long yan rou I stock and use in my clinical prescriptions and formulas for decades. Happily, they were.
Many wonder about the discovery of the medicinal properties of herbs: "How did they figure out that such-and-such herb has medicinal value?" In the case of Longan berries, and many other herbs, their first use was as a food, and the road of discovery began there.
Having only known this as a botanical medicine that I would frequently nibble on in my clinic and offer to patients as a pleasant introduction to Chinese herb tonics, I was excited about the prospect of eating Longan berries in their fresh, unadulterated form.
Eyes of the Dragon
Commonly known in Chinese as long yan rou, literally meaning "dragon eyes," the Longan berry is the fruit of a tropical tree found throughout Southeast Asia, including southern China, Malaysia, Indonesia and Vietnam. For the first time, I was able see and taste the syrupy sweet opalescent fruit which is like an iris with the hard lacquered black dark pit faintly showing in the center. When fully ripened, the freshly harvested outer shell is rough and bark-like and is easily cracked allowing one to squeeze out the inner fruit. The Chinese woman minding the fruit stand described how if the fruit is too ripe, the shell is soft and dark and the flavor is not so appealing.
The Vietnamese riddle aptly describes the experience of Longan fruit: Da cóc mà bọc bột lọc, bột lọc mà bọc hòn than (literally: Toad's skin covers tapioca flour, tapioca flour covers coal stone). Toad's skin is the skin, tapioca flour is the clear white flesh and coal stone is the black seed.
As a botanical, Longan berries are sold pitted and dried and they have a golden brown iridescent color. In order to more easily extract the seed from the rough outer skin and the pit from the fruit, they are lightly heated and smoked.
The Medicinal Properties of Longan
Longan berries are one of the three or more "super fruits" used as tonics in Chinese medicine. Two others would be jujube date (Zizyphus jujube) and goji berries (Lycium chinensis). Sometimes in my clinic I"d make a kind of Chinese herbal trail mix with Longan berries, lycii berries, fennel seeds, almonds and hemp seed. Apart from being a tasty snack, this works beautifully for diabetics and individuals suffering from chronic constipation.
The third generation Chinese woman tending the fruit stand was surprised that I apparently knew so much about the fruit she was selling. She confessed how she had even forgotten the Chinese name for Longan berries; I couldn't resist reminding her. I also told her and a woman deliberating whether to buy some or not about their use in traditional Chinese medicine as a blood tonic and as a tonic for Spleen and Heart, for low energy and with special benefit for the mind and improving memory. The Chinese fruit seller, who apparently had suppressed most of this to the general public out of embarrassment because of fear that they would not believe her, simply chimed in at the end something that most Chinese will revert to as a description for non-Chinese customers about a Chinese food herb: that they clean the blood.
While my fellow customer purchased her small bag of longans, I was given several samples to eat on the spot which I consumed with relish. These fruit are closely related to the more common lychee fruit and like that fruit, they are canned in syrup, made into a liqueur, confection, desserts and added as a natural sweetening ingredient in soups. I could easily imagine making a jelly or jam with them.
My personal sense of this herb is that it is indeed a powerful brain-nourishing food. It is high in glucose, and the brain relies on a steady supply of glucose for thought energy. The skull and brain usually contain about a third of the blood of the entire body. So it is easy to understand how glucose-rich Longan berries are used to counteract brain fatigue, anxiety, insomnia and poor memory. It is an essential herb to give to anyone but especially the aged who are prone to memory lapses, dementia and possibly Alzheimer's as well. In this regard it is useful for anyone who thinks a lot and may experience occasional brain fog. Despite their high sugar content I have prescribed both Longan berries and lycii berries to diabetics who found that they both actually helped regulate blood sugar.
However it is not only the glucose of Longan berries that make them a superior blood tonic. Apparently, they are high in blood-enriching iron content, reportedly 20 times that of grapes and 15 times that of spinach! Iron is an important blood nutrient which carries oxygen from the lungs to the cells of the body. This is obviously important for maintaining youthfulness and vitality (both being therapeutic claims for Longan berries). However they have a special benefit for women in that they add luster and beauty to the skin and their iron-rich "red-blooded" properties enhance female attractiveness and serve as a special tonic for sexual vitality. Those individuals who have iron sensitivity need not worry because the iron is organically present and the body will be better able to regulate its usage.
Longan berries have a generally calming effect, which apart from relieving symptoms of anxiety and sleeplessness, contributes to an overall feeling of calm.
Finally, Longan berries are very beneficial for the skin, hair and eyes.
Longan berries are a longevity power food and one needn"t wait until developing symptoms of anemia, fatigue, anxiety, insomnia and memory problems before having them prescribed by a medical herbalist. You can purchase them in bulk (they are reasonably priced) and keep, them on hand as occasion demands. You can even look into growing them if you live in an area where the temperature does not drop below 40 degrees Fahrenheit, or purchase them fresh from various online sources or Chinese markets.
It was a good moment encountering a beloved Chinese herb there on the highway in Kauai. I bought a $10 bag of fresh longan berries and managed to experience the one contraindication from eating too many of them, described as a "damp Spleen" which in Chinese diagnostics means a swollen and bloated fruit belly. (I also got to experience how taking a couple tablets of Planetary's Digestive Comfort, which I always have on hand when I travel, relieved this condition within 15 minutes!)