Does eating too many longans cause “internal heat”?
May 09, 2022
Source: Cainiu Health
Dr. Pan Yongyuan
Introduction
It is not recommended to consume large quantities, as this can still lead to “internal heat” (a traditional Chinese medicine concept referring to symptoms such as sore throat, acne, or constipation). Longan is a fruit native to southern China; many people in northern China refer to it as “guìyuán.” It differs from lychee. Both longan and lychee are southern fruits—sweet in taste and high in water content—making them refreshing and pleasant to eat. However, excessive consumption of longan can cause “internal heat.” It is advisable to limit intake to three to five longans (or guìyuán) per day, as eating more may easily trigger “internal heat.”
There is a wide variety of fruits available in daily life, each with distinct flavors—some people prefer sour fruits, others favor sweet ones, and some particularly enjoy longan due to its unique, fragrant aroma. So, can eating too much longan cause “internal heat” (a traditional Chinese medicine concept referring to excessive internal body heat)?
Can eating too much longan cause “internal heat”?
Consuming a small handful at home is generally fine; however, excessive intake is not recommended, as it may indeed trigger “internal heat.” Longan is a fruit native to southern China—many northerners refer to it as “guìyuán” (dimocarpus). Though similar to lychee, it is botanically distinct. As a southern fruit, longan is notably sweet and high in water content, offering a refreshing taste. Nevertheless, overconsumption may lead to “internal heat.” It is advisable to limit intake to three to five pieces per day; exceeding this amount increases the risk of “internal heat.” Longan—also known as “longan aril”—refers specifically to the edible fleshy part inside the guiyuan fruit. Dried longan is considered a warm-dry food in traditional Chinese medicine (TCM); excessive consumption of such warm-dry foods can indeed contribute to “internal heat.” Therefore, moderation is key: for medicinal use (e.g., in decoctions), a typical dosage is 10–15 g.
Longan is a tropical fruit—another name for guiyuan—and is highly valued in TCM as a nourishing fruit. It is rich in sugars—including glucose and sucrose—as well as proteins and various trace elements, especially iron. Its high caloric content helps replenish energy and nutrients, while its iron content supports hemoglobin regeneration, thereby exerting a blood-enriching (blood-tonifying) effect.
Individuals with digestive disorders, thick and greasy tongue coating, sore or swollen throat, toothache, or those exhibiting patterns of yin deficiency with internal heat should avoid consuming longan, as these are all manifestations of “internal heat.” We hope this information proves helpful!
