For more than two decades, apparently healthy children in the Indian region of Bihar suffered sudden seizures and lost consciousness. A third of them died, leaving doctors baffled.

But a team of American and Indian scientists say they have found the cause of the mystery illness, which killed more than 100 children a year: eating too many lychees on an empty stomach.

The research, published in medical journal The Lancet, has found lychees — particularly unripe fruits — contain an amino acid that affects blood glucose levels.

http://www.abc.net.au/news/2017-02-02/lychee-identified-as-cause-for-mystery-indian-childhood-illness/8233964

The full text of the original Lancet article is available here: http://www.thelancet.com/journals/langlo/article/PIIS2214-109×(17)30035-9/fulltext

Divine Angel said:

For more than two decades, apparently healthy children in the Indian region of Bihar suffered sudden seizures and lost consciousness. A third of them died, leaving doctors baffled.

But a team of American and Indian scientists say they have found the cause of the mystery illness, which killed more than 100 children a year: eating too many lychees on an empty stomach.

The research, published in medical journal The Lancet, has found lychees — particularly unripe fruits — contain an amino acid that affects blood glucose levels.

http://www.abc.net.au/news/2017-02-02/lychee-identified-as-cause-for-mystery-indian-childhood-illness/8233964

A slight problem with the report. “Litchi consumption” and “absence of an evening meal” were not determined by survey, so have to be inferred from the symptoms. This leads to circular reasoning. If the patient is sick with these symptoms then it is inferred that litchi consumption and absence of an evening meal occurred. The statistical link between the symptoms and “litchi consumption and absence of an evening meal” is really then just a measure of the statistical link between symptoms and symptoms – which not surprisingly shows a high correlation.

The problem seems to be “hypoglycin A or methylenecyclopropylglycine, naturally-occurring toxins in unripe fruit”. These reduce blood glucose levels to dangerous levels and cause neurological disorders.

What does the web tell us about these?

Methylene cyclo propyl glycine is a metabolite of hypoglycin A.

Hypoglycin_A is found in unripe fruits of the ackee, lychee, longan, and rambutan.

“The Sapindaceae are a family, known as the soapberry family, of flowering plants in the order Sapindales. The roughly 140–150 genera contain 1400–2000 species, including maple, ackee, horse chestnut, lychee, rambutan and longan. Many contain mildly toxic saponins with soap-like qualities in either the foliage and/or the seeds, or roots.”

I happen to know from my own reading about toxic plants that saponins are exceedingly common and not very dangerous plant poisons. They dissolve in water, so boiling the fruit before eating it is likely to reduce any poisoning effect.