By Katie Worth
Copyright ©2003 Pacific Daily News. All rights reserved.

A Hawaiian ethnobiologist says he has made a conclusive connection between Chamorros' love of fruit bats and the high incidence of the neurodegenerative diseases lytico-bodig on Guam.

But local neurologists researching patients of the diseases say that conclusion is premature and do not believe the bat connection explains the high incidence of the diseases on Guam.

The controversy represents another fold in the long search for the causes of neurodegenerative diseases lytico -- now known as ALS or Lou Gehrig's Disease -- and bodig, now known as Parkinson's Dementia Complex. Bodig exists only on Guam.

The diseases have affected thousands of Guam residents, and seem to be particularly prevalent in the southern villages of Merizo, Umatac and Inarajan, according to Pacific Daily News files.

The study was led by professor Paul Cox, the director of the National Tropical Botanical Garden on Kauai, and was published in the Proceedings of the National Academy of Sciences, according to The Associated Press.

Cox said the prevalence of Parkinson's on island can be explained by Chamorros' consumption of fruit bat. The bats, the theory goes, eat seeds from the cycad trees on island, which Cox said contain the neurotoxic non-protein amino acid BMAA.

He said that same chemical can be found in Chamorros with Parkinson's disease and in bat tissues his team studied.

Before the bat became endangered, it was common for Chamorros to eat the winged creatures after they boiled the bats in coconut milk.

Guam residents also have eaten the cycad seeds in other forms, including tortillas, but Cox told The Associated Press that people would have to eat the seeds in very large amounts to accumulate enough BMAA to be dangerous.

Cox said in a study of Canadians who have had no contact with Guam, BMAA was not found in healthy people but was found in Alzheimer's or Parkinson's patients.

This discovery, Cox said, suggests that BMAA may be accumulated through other ecological pathways as well.

Agat Mayor Johnny M. Reyes said his father suffered from lytico-bodig in the 1960s and also ate fruit bats regularly.

Reyes said before the war, his family would collect the bats, called fanihi in Chamorro, with traps, and after the war his father would hunt them. He recalled that his father would gather all of the older boys in the family to go out to collect betel nut, and when they came across bats, they would catch them and bring them home to eat as a delicacy.

Questions

But local researchers are not so sure about the connection between bats and Parkinson's disease.

Neurologist Dr. Kwang-Ming Chen had concerns about the methodology used by Cox's team. One of his complaints was that the bats autopsied to determine the concentration of BMAA were museum specimens, which he said could not adequately be tested.

Roy Salvador Adonay, associate director for the University of Guam's Micronesian Health and Aging Studies, said his lab's research does not support Cox's conclusions.

"If that's right, why do we have patients that have never once eaten bats?" he asked.

Bat biologist Dustin Janeke, who does research with the Department of Agriculture and UOG, said he, too, is not convinced that the study's conclusion is correct. However, he said he will provide tissues of bats he captured to Cox and his colleagues in Hawaii for further research.

Janeke said in his time observing bats, he has never seen one eat a cycad, though he said other researchers have said they have.

Further, he noted, pigs and deer are known to eat cycad seeds, as well as the trees' leaves and trunks, and wondered why that connection has never been explored.

And though the neurotoxin has been found in the brains of Parkinson's disease patients, there is no study concluding that the toxin causes that disease, Janeke said.

"Correlation does not mean causation," Janeke said. "I would like to see them make the firm connection before they start going around blaming people for eating bat."

There have been other theories about the cause of the high incidence of the brain disease.

Earlier this year, a recent U.S. Geological Survey study suggested that algae and bacteria found in southern rivers -- likely once used as an untreated water source -- could be the source of the high incidence of lytico-bodig.

Algae and bacteria release toxins at certain times of the year, and long periods of ingestion could cause such a neurodegenerative disease as what was once called lytico-bodig, the study said.

The Associated Press contributed to this report.