EATING flying foxes which had consumed palm seeds may be the
reason why a small group of Pacific Island people were devastated
by a terrifying mental illness, according to new research published in an American academic journal, Neurology.
It reports that the disease may have declined because fruit bats on Guam
died out and the imported Samoan flying foxes do not eat palm
seeds.
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One of those who solved the mystery is the celebrated New York
neurologist Oliver Sacks whose best known book, ”Awakenings”, was
turned into a movie in which he was played by Robin Williams. It
told of how he used the drug L-Dopa to bring post-encephalitic
patients out of deep comas.
The indigenous Chamorro people of Guam have at times been devastated
by lytico-bodig, an extremely rare mental disease which leaves
people seemingly conscious and awake, but completely vacant.
There is no cure. It has also been recorded in a part of Japan
and Papua New Guinea and today is known as ”amyotrophic lateral
sclerosis/parkinsonism-dementia” (ALS-PDS).
Sacks and Dr Paul Cox of Hawaii’s National Tropical Botanical
Garden write in Neurology that the high incidence of ALS-PDC had
been an enigma.
Confined to the Chamorro it climaxed in the 1940s when it was
the main cause of adult death and today it only occurs in older
adults and rarely in any individual born after 1960.
There was no genetic link to the disease, nor infectious origin.
Researchers suspected the seeds of the cycad palm tree but
Chamorro knew they were toxic and only ate the seeds in a flour
form which washed out the toxins.
”We suggest that the Chamorro … ingested large quantities of
cycad toxins indirectly by eating flying foxes,” Sacks and Cox
write.
They were eaten in ceremonial occasions and their consumption
was a core part of Chamorro custom, particularly in the villages of
Umatac and Inarajan – both of which have the highest incidences of
the disease.
The authors found the flying foxes sometimes consume up to two-and-a-half times their body weight per night in fruit and nectar –
and that they were particularly fond of cycad seeds.
Eating the bats became highly popular and by the late 1970s the
species had been hunted to near extinction.
Sacks and Cox say massive importation of flying foxes from Samoa
followed: about 18 000 flying foxes at $35 a carcass.
The Pacific Daily News in Guam reported on Wednesday that the Chamorro were still occasionally eating local flying foxes.
”People should not be unduly frightened if they have eaten fruit
bat,” University of Guam expert Ulla-Katrina Craig told the
newspaper.- Sapa-AFP