The longan fruit, also known as lamyai or dragon eye fruit, is a small round brown fruit packed with essential nutrients.
The longan tree (botanical name – Dimocarpus longan) is an evergreen tree in the family Sapindaceae, native to southern China. In the present day, longan crops are grown in southern China, Cambodia, Thailand, Laos, India, Vietnam, Sri Lanka, United States, and Australia.
This fruit is a rich source of many vitamins, such as vitamin B1, B2, B3, B5, B6, B9 (folate) C, E, K; minerals which include – iron, phosphorus, manganese, magnesium, copper, calcium, selenium, zinc, and potassium; dietary fiber, and approximately 60 calories/100g of fruit.
Health Benefits of Longan Fruit
Copper is necessary for supporting neurodevelopment and growth, proper cognitive function. This is why food with a high copper content is often classified as “Brain Food”. It is the 3rd most prevalent mineral in the body and it is mainly carried by the blood plasma protein, Ceruloplasmin.
However, copper content in the diet has to be in correct proportions, because ingesting too much of this mineral is not healthy for the brain. 100g of this fruit contains 19% copper of the recommended daily intake.
Fiber is found in foods that come from plants (vegetables, fruits, beans, nuts, seeds, and grains). The health authorities recommend that men eat minimum 38 grams per day and that women eat 25 grams of fiber per day.
There are numerous studies that have concluded that increasing dietary fiber intake can cause weight loss by automatically reducing a total calorie intake (1).
Other benefits of dietary fiber include their important role in slowing down the absorption of fat from what you eat and promotes overall colon health by encouraging the growth of beneficial bacteria and discouraging the growth of harmful bacteria in the intestines.
100g of this fruit contains 3% percent fiber of the recommended daily intake for an adult male.
Rich in natural sugars
This fruit is rich in sugar, particularly the digestible monosaccharides which are the basic building block of any carbohydrate. Furthermore, the fructose in fruits has a natural advantage over refined sugar because fruits contain so many minerals, vitamins, fiber, and nutrients.
According to a review of observational studies published in the Journal of the American Medical Association has concluded that increased daily fruit consumption is tied to lower BMI and a lower risk of obesity-related diseases (2).
According to the ADA – American Diabetes Association, fruits are loaded with minerals, vitamins, and dietary fiber and should be a part of a diabetes-friendly diet.
Researchers at Harvard University studied the risk of type 2 diabetes in a large population – 40,000 men and 160,000 women – who were tracked for nearly three decades.
The individuals who consumed fewer unhealthy carbs, such as fruit juices, sugary drinks, and refined grains, and more healthy carbs like vegetables, fruits, beans, and whole grains had a 34 percent lower risk of type 2 diabetes, regardless of their weight (3).
Potassium is considered an essential mineral that is required in somewhat large amounts. Low potassium diets have been associated with cardiovascular disease and high blood pressure.
In a study, people who consumed 4,069 milligrams of this mineral daily had a 49% lower risk of death from a blockage of the arteries compared with people who ate less than 1,000 milligrams of potassium per day (4).
In addition, ingesting potassium-rich foods is crucial to help maintain a balance between the electrical and chemical processes in your body. 100g of this fruit contains 6% percent potassium of the recommended daily intake.
Folate, which is also known as vitamin B9, is a water-soluble B-vitamin. Consuming a high level of folate during pregnancy helps reduce the risk of birth defects in the infant.
Additionally, a folate deficiency can lead to mouth ulcers, gray hair and poor hair growth, peptic ulcers, and swollen tongue.
Moreover, elevated concentrations of homocysteine in the blood and vitamin B9 deficiency are strongly linked with increased risk of some serious conditions, especially cardiovascular disease. 100g of this fruit contain 4% percent folate of the recommended daily intake.
The seeds of this fruit contain plant compounds named saponins that offer tremendous health benefits. According to a 1995 study at the University of Toronto, Canada, saponins slow the growth of human cancer cells (5).
It’s also considered that saponins have a positive effect on lowering LDL cholesterol, have an antioxidant effect, can help boost the immune system, and may even support bone strength.
Vitamin B1, also known as thiamine, is a vital human nutrient that belongs to the vitamin B complex. Thiamine is needed for pyruvate dehydrogenase (a system of enzyme reactions), that works to oxidize sugars that we consume (6).
Furthermore, this vitamin promotes the health of the nervous system, hair, skin, eyes, mouth, and liver. A vitamin B1 deficiency can cause a disorder called beriberi, that has been seen in populations for thousands of years.
100g of this fruit contains 3% percent vitamin B1 of the recommended daily intake.
Helps wound healing
Health benefits of pantothenic acid, also known as vitamin B5, include the alleviation of conditions like allergies, asthma, hair loss, anxiety and stress, heart problems and respiratory disorders.
Data gathered from studies suggest that vitamin B5 induces an accelerating effect of the normal healing process due to certain systems that help control the cellular multiplication (7).
In addition, individuals at a greater risk of developing a pantothenic acid deficiency include women on birth control pills, alcoholics, or people with severe malnutrition. 100g of this fruit contains 4% percent pantothenic acid of the recommended daily intake.
There are no known adverse effects. However, pregnant women shouldn’t eat too much of this kind of fruit.
Selection and storage
Choose a fruit which is firm and free of blemishes and bruises. A ripe fruit, which usually appears between July and September, will have an intense tan color.
You can store these fruits in a container that is slightly open or a plastic bag in the refrigerator for up to 2 weeks. The small opening will help to reduce mold and condensation. In addition, you can freeze these fruits. Dragon eye fruit will keep about a year in the freezer.
How to eat
Dragon eye fruit can be consumed both raw or as dried fruit. The seed and the shell are not consumed. The fully ripened, freshly harvested fruit has a bark-like shell, thin, and firm.
To eat this fruit, simply remove the skin and eat the white pulp and discard the seed. When dried, the fruit becomes a lovely golden color and has a flavor, unlike any other dried fruit.
Asian people usually consume the fruit in desserts, soups, snacks, or in canned foods.
Longans are about 3 cm in diameter but the lychees are a little bigger. They both have the appearance of grapes on the inside, and kindly a similar flavor.
They both have one dark brown seed in the middle. Lychee is much tastier but dragon eye fruit is even better from a nutritional point of view.