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By Michael Field

AUCKLAND, New Zealand (March 27, 2002 – Agence France-Presse)---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, research published in the American Academy of Neurology journal, Neurology, says.

And the disease may have declined because fruit bats on Guam died out and the imported Samoan flying foxes do not eat palm seeds.

One of those who apparently 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.

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 Hawai‘i'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, or 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 during ceremonial occasions and their consumption was a core part of Chamorro custom, particularly in the villages of Umatac and Inarajan -- both of which have had 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; around 18,000 flying foxes at US$ 35 a carcass.

"Because there are no indigenous cycads in Samoa and many other bat-exporting islands, flying foxes imported from such places would not contain any cycad toxins.

"Thus the Chamorro people were no longer exposed to this putative source of cycad toxins. The decline of ALS-PDC among the Chamorro mirrors the decline of flying foxes in Guam."

The Pacific Daily News in Guam reported Wednesday that 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.

Michael Field New Zealand/South Pacific Correspondent Agence France-Presse E-mail:  Phone: (64 21) 688438 Fax: (64 21) 694035 Website:  Website: 

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