For many Malaysians, lychees (scientific name Litchi chinensis Sonn) – or litchis as they are known in some parts of the world – are a rather exotic kind of fruit. Canned lychees are available in many supermarkets, usually served as part of a fruit cocktail or used to enhance the flavours of beverages and desserts. Fresh lychees are also available for those who prefer to keep their foods as natural as possible.
In February 2017, however, researchers discovered that lychees were the cause of a mysterious ‘plague’ that affected the children in a town in Bihar, India. Around May and June, many children in Muzaffarpur experienced seizures and convulsions that would cause them to slip in and out of consciousness. This condition, called ‘chamki ki bimari’ (tinsel disease) by the locals, caused hundreds of children to end up in the hospital. In 2014, it was reported that 122 of the 390 children admitted died from this disease.
The Dark Side of Lychees
After much research, it is now found that the lychee was the cause. India is the world’s largest lychee producer after China, and Bihar is one of the main ‘lychee states’ of India. Thus, lychee orchards are a common part of the Muzaffarpur landscape.
According to the report that was published in The Lancet, the affected children all consumed lychees before showing symptoms of the disease. Urine studies suggested that lychee seeds, especially unripe ones, can produce toxins that eventually hamper glucose production in these children. As a result, they experience dangerously low blood sugar levels, a state that could lead to potentially fatal brain inflammation.
Not all children are affected, however, so the researchers speculate that genes may also play a role in how these toxins interact with the body.
Lychees by themselves need not necessarily be ‘bad’ for health. As the researchers noted, there were other factors that worsened the effects of the toxins to such an extent.
“The synergistic combination of litchi consumption, a missed evening meal, and other potential factors such as poor nutritional status, eating a greater number of litchis, and as yet unidentified genetic differences might be needed to produce this illness,” the study concluded.
Proven and Potential Benefits
Lychees are a very good source of vitamin C and a good source of copper, a nutrient that plays an important role in maintaining the functions of our organs. We should not go overboard, though – lychees have high sugar content, so we should consume them in moderation.
Furthermore, it is possible that lychees can confer some protective benefits against certain diseases. Research on this is at an early stage (tests are still being done on animals), but some interesting studies yielded the following possibilities:
• The livers of mice given lychee pulp phenolic extract (LPPE) showed greater antioxidant activity and reduced fat production. This suggests that moderate intake of LPPE may be useful in the prevention or control of alcoholic liver disease.
• Lychee seeds are rich in a compound called phenolics, and studies done in laboratories suggested that these compounds could help inhibit the growth of non-small cell lung carcinoma (NSCLC).
• Lychee seed extracts were also found to cause reduction in the size of prostate tumours in rats, suggesting their potential usefulness in treating prostate cancer.
The Final Word?
Unfortunately, we cannot conclusively decide whether lychees are ‘good’ or ‘bad’ as we still have much to learn about the fruit. The best approach is to keep to the basics: eat in moderation, based on our daily recommended nutrient intake, and work off the excess calories by being regularly active. If we have any doubts or concerns, we can consult a dietitian for advice.
1. Chung, Y. C., et al. (2017). Litchi seed extract inhibits epidermal growth factor receptor signaling and growth of two non-small cell lung carcinoma cells. BMC Complement Altern Med.;17(1):16.
2. Guo, H., et al. (2017). Litchi seed extracts diminish prostate cancer progression via induction of apoptosis and attenuation of EMT through Akt/GSK-3β signaling. Sci Rep;7:41656.
3. SELFNutrition Data. Litchis, raw [lychee] nutrition facts & calories. Retrieved on Feb 2, 2017 from http://nutritiondata.self.com/facts/fruits-and-fruit-juices/1945/2
4. Shrivastava, A., et al. (2017). Association of acute toxic encephalopathy with litchi consumption in an outbreak in Muzaffarpur, India, 2014: a case-control study. Lancet Glob Health.
5. Spencer, P.S, et al. (2015). Probable toxic cause for suspected lychee-linked viral encephalitis. Emerg Infect Dis.; 21: 904–905.
6. Su, D., et al. (2017). Lychee pulp phenolics ameliorate hepatic lipid accumulation by reducing miR-33 and miR-122 expression in mice fed a high-fat diet. Food Funct.
7. Xiao, J., et al. (2017). The biphasic dose effect of lychee (Litchi chinensis Sonn.) pulp phenolic extract on alcoholic liver disease in mice. Food Funct.;8(1):189-200.