Dimocarpus longan
1 association assessed — none with dependable human evidence behind them yet. Strongest first.
A small brown-shelled relative of lychee with translucent flesh around a dark seed, giving it the Chinese name dragon eye. Sold fresh in season and dried for use in soups and teas.
Also known as Dragon eye, Longyan, Lungan
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how impressive the food is. How we rate evidence.
Longan appears in traditional formulas said to support memory and calm, and a little animal work exists. There is no human trial of the fruit and no basis for a claim.
Insufficient evidence. Not enough human research to say anything useful yet.
Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.
AI explanations are not switched on for this site, so there is nothing to ask here. Everything above is read straight from the database and does not need them.
| Nutrient | Amount | % DV |
|---|---|---|
| Macronutrients | ||
| Calories | 60 kcal | 3% |
| Protein | 1.31 g | 3% |
| Total fat | 0.1 g | 0% |
| Carbohydrate | 15.1 g | 6% |
| Fibre | 1.1 g | 4% |
| Water | 82.8 g | — |
| Fats | ||
| Cholesterol | 0 mg | 0% |
| Vitamins | ||
| Vitamin C | 84 mg | 93% |
| Thiamin (B1) | 0.031 mg | 3% |
| Riboflavin (B2) | 0.14 mg | 11% |
| Niacin (B3) | 0.3 mg | 2% |
| Vitamin B12 | 0 µg | 0% |
| Minerals | ||
| Calcium | 1 mg | 0% |
| Iron | 0.13 mg | 1% |
| Magnesium | 10 mg | 2% |
| Phosphorus | 21 mg | 2% |
| Potassium | 266 mg | 6% |
| Sodium | 0 mg | 0% |
| Zinc | 0.05 mg | 0% |
| Copper | 0.169 mg | 19% |
| Manganese | 0.052 mg | 2% |
| Other measured compounds | ||
| Ash | 0.7 g | — |
Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.
Source record: Longans, raw (USDA FoodData Central, FDC ID 169089).
% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.
Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.
Polyphenol (class)
An umbrella term for thousands of plant phenolic compounds. Useful as a category, but a "high polyphenol" figure says nothing about which compounds…
Hydrolysable tannin
Tannins in pomegranate, walnuts and berries. Gut bacteria convert them to urolithins, and only some people carry the microbes that do it efficiently.
Mainly in the seed and shell rather than the flesh.
Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.
Nothing dependable is recorded about how preparation changes this food’s nutritional properties. Rather than guess, this section stays empty.
Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.
Too much
Dried longan is a staple of sweet Chinese soups and tonics and is very high in sugar by weight. It is eaten in quantities that fresh fruit rarely reaches.
Allergy
Longan shares a family with lychee and rambutan, and reactions in people allergic to one of them have been described.
Worth knowing
The single hard seed is discarded. It is smooth and round enough to be a choking risk for young children if fruit is served unpitted.