Dried Longan
Also known as: Dimocarpus longan, Longan, Dried longan, Longan arillus, Dragon eye fruit
Overview
Dried longan is the dehydrated fruit of *Dimocarpus longan*, a tree native to Southeast Asia. It is commonly used in traditional medicine and cuisine. The fruit is characterized by its high sugar content and is rich in polysaccharides and polyphenols. These compounds are being investigated for their potential effects on energy levels, sleep quality, metabolic health, glucose metabolism, and gut health. However, it's important to note that current research is primarily preclinical, involving animal models, with limited human clinical trials. The available evidence is moderate for animal studies but low for human randomized controlled trials (RCTs). No systematic reviews or meta-analyses specifically focusing on dried longan as a supplement in humans have been identified in major databases. Therefore, while promising, the benefits observed in animal studies may not directly translate to humans, and further research is needed to confirm these effects.
Benefits
Animal studies suggest that longan extract (LE) supplementation may reduce fasting blood glucose, improve glucose tolerance, and reduce epididymal fat accumulation in diabetic (*db/db*) mice. LE supplementation has also been shown to reduce food intake and hypothalamic endoplasmic reticulum stress in these mice. These effects are statistically significant in animal models, but the effect sizes and clinical relevance for humans are uncertain. The benefits were observed over several weeks of supplementation in animal studies, but the exact onset and duration are not specified. Overall, while animal data suggests potential metabolic benefits, human data is lacking, and clinical recommendations cannot be made at this time.
How it works
In animal models, longan extract (LE) appears to modulate hypothalamic feeding centers, specifically increasing POMC and decreasing AgRP neuronal activity, which may reduce food intake and improve glucose homeostasis. LE may also influence inflammation and gut health. However, excessive intake may promote inflammation (increased IL-1β, TNF-α) and alter gut microbiota, potentially aggravating colitis. Polysaccharides in longan are poorly absorbed and may act via gut microbiota modulation, while polyphenols have variable absorption, and their metabolites may exert systemic effects.
Side effects
Animal studies suggest that dried longan is generally safe at normal doses, but excessive intake may disrupt gut homeostasis and promote inflammation. Common side effects have not been reported in the reviewed animal studies, and human data is lacking. Due to its high sugar content, dried longan may affect glycemic control in individuals with diabetes, posing a theoretical risk of interaction with hypoglycemic agents. Individuals with inflammatory bowel disease or colitis may be at risk of exacerbation with excessive intake. Diabetics should monitor their blood glucose levels, and individuals with gut disorders should be cautious, as excessive intake may worsen symptoms.
Dosage
Due to limited human data, specific dosage recommendations for dried longan are not well-established. Animal studies vary in their dosages, and human equivalents have not been determined. Excessive intake (beyond normal dietary levels) may be harmful, based on animal data. Most research uses extracts, while whole dried fruit may have a higher sugar content. Polysaccharides in longan are poorly absorbed and dependent on gut microbiota. Until more research is available, it is difficult to determine a minimum effective dose, optimal dosage range, or maximum safe dose for humans.
FAQs
Is dried longan safe to consume?
In moderation, dried longan appears to be safe. However, excessive intake may disrupt gut health and promote inflammation, according to animal studies. Human data is lacking, so caution is advised.
Can dried longan help with diabetes?
Animal studies suggest potential benefits for glucose homeostasis, but human evidence is lacking. The high sugar content may be a concern for diabetics, so monitor blood glucose levels carefully.
How much dried longan should I eat?
Due to limited research, there are no established dosage guidelines for humans. Animal studies suggest that excessive intake may have adverse effects, so moderation is key.
Are the benefits of dried longan scientifically proven?
Most benefits are observed in animal models. Human evidence is lacking, so the effects observed in animals may not directly translate to humans.
Research Sources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8033040/ – This animal study on mice with colitis found that excessive longan intake increased inflammatory markers (IL-1β, TNF-α), gut permeability, and aggravated colitis. The study also showed that excessive longan intake altered the gut microbiota composition. While well-controlled, the findings are limited by the use of an animal model, making human relevance uncertain.
- https://onlinelibrary.wiley.com/doi/full/10.1002/fft2.185 – This animal study found that excessive longan intake promoted non-alcoholic fatty liver disease (NAFLD) via gut dysbiosis and increased de novo lipogenesis. The study suggests a link between high sugar intake from longan and the development of NAFLD. As with other animal studies, the human relevance of these findings remains uncertain.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10322219/ – This animal study on diabetic mice found that longan extract (LE) supplementation improved glucose homeostasis, reduced food intake, and decreased fat accumulation via hypothalamic regulation. The study suggests that LE may modulate POMC and AgRP neurons in the hypothalamus. The findings are limited by the use of an animal model, and further research is needed to determine if these effects translate to humans.
- https://www.mdpi.com/2072-6643/16/11/1654 – This review discusses the potential health benefits of longan fruit, including its antioxidant and anti-inflammatory properties. It highlights the presence of bioactive compounds such as polysaccharides and polyphenols. However, it also notes the need for more human studies to confirm these benefits and establish safe dosage guidelines.
- https://onlinelibrary.wiley.com/doi/pdf/10.1002/fft2.185 – This study investigates the impact of excessive consumption of sugar-rich longan fruit on the development of non-alcoholic fatty liver disease (NAFLD). The research indicates that high intake of longan fruit can promote NAFLD through gut dysbiosis and increased de novo lipogenesis. The findings suggest a potential link between excessive longan consumption and liver health, warranting further investigation.