by Oliver Sacks
These were some of the clues and contradictions, John continued, which faced Kurland and Mulder when they came here in the 1950s – and which are so difficult to reconcile by any single theory. Kurland was at first inclined to think in terms of a genetic origin. He looked at the early history of the island, and how a near genocide reduced the population from 100,000 to a few hundred – the sort of situation which disposes to the spread of an abnormal trait or gene (as with the achromatopsia on Pin-gelap) – yet there was no simple Mendelian pattern linking those with the disease. He wondered, in the absence of such a pattern, whether this was a gene with ‘incomplete penetrance.’ (He wondered too if a genetic predisposition to lytico-bodig might also have a paradoxical, selective advantage – perhaps increasing fertility or conferring immunity to other diseases.) But he had to wonder whether there might not be some environmental factor, in addition to a genetic susceptibility, a ‘necessary adjunct,’ as he put it, to developing the disease.
In the late 1950s he extended his studies to the very large population of Chamorros who had migrated to California. They had, he observed, the same incidence of lytico-bodig as the Chamorros in Guam, but the disease might only develop ten or twenty years after they had left Guam. There were, on the other hand, a few non-Chamorro immigrants who seemed to have developed the disease a decade or two after moving to Guam and adopting a Chamorro lifestyle.
Could the environmental factor, if there was one, be an infectious agent, a virus, perhaps? The disease did not appear to be contagious or transmissible in any of the usual ways, and no infectious agent could be found in the tissues of those affected. And if there was such an agent, it would have to be one of a very unusual sort, one which might act as a ‘slow fuse’ – John repeated the phrase for emphasis – a slow fuse in the body, setting off a cascade of events which only later might manifest as clinical disease. As John said this, I thought of various post-viral neurodegenerative syndromes, and especially again of my postencephalitic patients, who in some cases only started to show symptoms decades after the initial encephalitis lethargica – sometimes as much as forty-five years later.
At this point in the story, John started pointing emphatically through the window. ‘Look!’ he said. ‘Look! Look! Cycads!’ Indeed I saw cycads all round, some growing wild but many, I now saw, cultivated in gardens, as we drove to Talofofo to visit another patient of John’s, a former mayor of the village, whom everyone called the Commissioner.
Cycads only grow in tropical or semitropical regions and were new, alien, to the early European explorers when they first saw them. At first glance, cycads bring to mind palms – indeed the cycad is sometimes called a sago palm – but the resemblance is superficial. Cycads are a much more ancient form of life, which arose a hundred million years or more before there were palms or any other flowering plants.
There was a huge native cycad, at least a century old, growing in the Commissioner’s yard, and I stopped to gaze at this splendid tree, fondled a stiff, glossy frond, then caught up with John at the front door. He knocked on the door, and it was opened by the Commissioner’s wife, who ushered us into the main room where her husband sat. Sitting in a massive chair – rigid, immobile, and parkinsonian, but with a sort of monumental quality, the Commissioner looked younger than his seventy-eight years and still exuded a sense of authority and power. Besides his wife, there were his two daughters and a grandchild – he was still, for all his parkinsonism, very much the patriarch of the house.
In a deep musical voice, as yet scarcely touched by parkinsonism, the Commissioner told us of his life in the village. He had at first been a cattle rancher, and the village strongman, able to bend horseshoes with his bare hands (his hands, gnarled now, and slightly tremulous, still looked powerful enough to crush stones). Later he had been a teacher in the village school; and then, after the war, he had been drawn more and more into village affairs – very complex and unsettled after the Japanese occupation, and with all the new pressures of Americanization on the island, trying (without being ‘backward’) to preserve the traditional Chamorro ways and myths and customs – finally becoming mayor. His symptoms had begun eighteen months ago, at first with a strange immobility, a loss of initiative and spontaneity; he found he had to make a huge effort to walk, to stand, to make the least movement – his body was disobedient, seemed disconnected from his will. His family and friends, who had known him as a driving, energetic man, first took this as aging, a natural slowing down after a life of intense activity. Only by degrees did it become clear to them, and him, that this was an organic malady, an all-too-familiar one, the bodig. This fearful, thick immobility advanced with frightening speed: within a year he had become unable to get up alone; once up, unable to sense or control the posture of his body, he might fall suddenly and heavily, without warning, to either side. He now had to have a son-in-law, a daughter, with him all the while, at least if he wanted to get up and go anywhere. He must have found this humiliating in a way, I thought, but he seemed to have no sense of being a burden, imposing on them, at all. On the contrary, it seemed natural that his family should come to his aid; when he was younger he too had had to help others – his uncle, his grandfather, two neighbors in his village who had also contracted the strange disease he himself now had. I saw no resentment in his children’s faces or their behavior; their helping seemed entirely spontaneous and natural.
I asked, a little diffidently, if I might examine him. I still thought of him as a powerful authority figure, not someone to lay hands on. And I was still not quite certain of local customs: Would he see a neurological examination as an indignity? Something to be done, if at all, behind closed doors, out of sight of the family? The Commissioner seemed to read my mind, and nodded. ‘You can examine me here,’ he said, ‘with my family.’
When I examined him, testing his muscle tone and balance, I found fairly advanced parkinsonism, despite the fact that his first symptoms had begun little more than a year before. He had little tremor or rigidity, but an overwhelming akinesia – an insuperable difficulty in initiating movement, greatly increased salivation, and profound impairment of his postural sense and reflexes. It was a picture somewhat unlike that of ‘ordinary’ Parkinson’s disease, but more suggestive of the much rarer post-encephalitic form.
When I asked the Commissioner his thoughts on what might have caused his illness, he shrugged. ‘They say it is fadang,’ he said. ‘Our own people sometimes thought this, and then the doctors too.’
‘Do you eat much of it?’ I asked.
‘Well, I liked it when I was young, but when they announced it was the cause of lytico-bodig I quit, we all did.’ Despite concerns about the eating of fadang as far back as the 1850s (which Kurland had reiterated in the 1960s), the notion that it might be dangerous was only widely publicized in the late 1980s, so this quitting, for the Commissioner, must have been relatively recent – and he was evidently nostalgic for the stuff. ‘It has a special taste,’ he said, ‘strong, pungent. Ordinary flour has no taste at all.’ Then he motioned to his wife, and she brought out a huge bottle of cycad chips – obviously the family supply, and one which they had not thrown away, but were still at pains to keep, despite the decision to ‘quit.’ They looked delicious – like thick corn chips – and I was strongly tempted to nibble them, but refrained.
The old man suggested we all go outside for a photograph before we left, and we lined up – his wife, himself, and me in the middle – in front of the giant cycad. Then he walked slowly back to the house, a regal figure, a parkinsonian Lear, on the arm of his youngest daughter – not merely dignified in spite of his parkinsonism, but somehow gaining a strange dignity from it.
There had been some controversy about the local cycads for two centuries or more. John was interested in the history of Guam and had copies of documents from the early missionaries and explorers, including a Spanish document from 1793, which praised fadang or federico as ‘a divine providence,’ and Frey-cinet’s 1819 Voyage Autour du Mond
e, in which he described seeing this harvested on a large scale in Guam.48 He described the elaborate process of soaking and washing the seeds, and drying and grinding them to make a thick flour ideal for tortillas and tamales and a soup or porridge called atole – all this is illustrated in his account. It was well known, Freycinet remarked, that if the seeds were not washed sufficiently, they might still be highly poisonous:
A bird, goat, sheep or hog that drinks from the first water in which the federico has been soaked is apt to die. This does not happen with the second, much less the third, which can be consumed without danger.
Although this washing of the seeds was supposed to be effective in leaching out their poisons, several governors of Guam were to express reservations, especially when federico became the main article of the diet (as happened, typically, after typhoons, when all the vegetation was destroyed except for the tough cycads).
Thus Governor Pablo Perez wrote, in the famine of 1848, that
…not having sweet potatoes, yams and taro, food staples destroyed by the storm, [the Chamorros] have to betake themselves to the woods to seek there the few fruits which are left, which, though noxious, they use as a last resource…This is now their chief staple of food; and notwithstanding the precautions with which they prepare it, all believe that it is injurious to health.
This was echoed by his successor, Don Felipe de la Corte, seven years later, who singled out federico as the most dangerous of all the ‘fruits…of the forest.’49
Kurland, a century later, having found no clear evidence for an infectious or genetic origin for the lytico-bodig, now wondered whether some element of the Chamorro diet might be the pathogen he sought; and he invited Marjorie Whiting, a nutritionist working on Pohnpei, to come to Guam to investigate this. Whiting had a special interest in indigenous plants and cultures of the Pacific islands, and as soon as Kurland outlined the problem to her, she was fascinated and agreed to come. On her first visit to Guam, in 1954, she spent time in two very different communities – Yigo, which is close to Agana, and part of the Westernized, administrative center of the island; and Umatac, where she lived in a traditional Chamorro household. She became very close to the Chamorro family, the Quinatas, with whom she lived, and often joined Mrs. Quinata and the women of the village in preparing special dishes for Umatac’s frequent fiestas.
Cycads had never particularly attracted her attention before (there are no cycads on Pohnpei) – but now everything she encountered seemed to direct her attention to the local species, so common on Guam and the neighboring island of Rota. Cycas circinalis was indigenous, it grew wild, it was free, it required only the labor of collection and preparation.
I had met Marjorie in Hawaii, on my way to Micronesia, and she had told me some vividly personal anecdotes from her time on Guam. She had gone out to do field studies each day for six months, coming back each evening to her Chamorro family – she only discovered later, somewhat to her chagrin, that the rich soups she had been served every day had all been thickened with fadang. People were well aware of its toxic properties and the need for very elaborate washing, but enjoyed the taste of fadang, and especially prized it for making tortillas and thickening soup, ‘because of its peculiar mucilaginous quality.’ The Chamorros sometimes chewed the green outer seed husks to relieve thirst; when dried, the husks were considered a tasty sweet.
Whiting’s experience in Guam initiated an entire decade of research in which, collaborating at times with the botanist F.R. Fosberg, she made an encyclopedic investigation of cycads around the world, and their use by dozens of different cultures as foods, medicines, and poisons.50 She undertook historical research, exhuming incidents of cycad poisoning among explorers as far back as the eighteenth century. She put together the scattered but voluminous evidence on the neurotoxic effects of cycads in various animals. Finally, in 1963, she published a detailed monograph on her work in the journal Economic Botany.
There were approximately a hundred species of cycad around the world, and nine genera,51 she noted, and most of these had been used as sources of food, containing as they did large quantities of edible starch (sago), which could be extracted variously from the root, stem, or nut.52 Cycads were eaten not merely, Whiting noted, as a reserve during times of shortage, but as a food with ‘a special prestige and popularity.’ They were used on Melville Island for first-fruit rites; among the Karawa in Australia for initiation ceremonies; and in Fiji, where they were a special food reserved only for the use of chiefs. The kernels were often roasted in Australia, where settlers referred to them as ‘blackfellows’ potatoes.’ Every part of the cycad had been used for food: the leaves could be eaten as tender young shoots; the seeds, when green, could be ‘boiled to edible softness; the white meat has a flavor and texture…compared to that of a roasted chestnut.’
Like Freycinet, Whiting described the lengthy process of detoxification: slicing the seeds, soaking them for days or weeks, drying and then pounding them, and, in some cultures, fermenting them too. (‘Westerners have compared the flavor of fermented cycad seeds with that of some of the best-known European cheeses.’) Stems of Encephalartos septimus had been used in parts of Africa to make a delicious cycad beer, she wrote, while the seeds of Cycas revoluta were used, in the Ryukyu Islands, to prepare a form of sake.53 Fermented Zamia starch was regarded as a delicacy throughout the Caribbean, where it was consumed in the form of large alcoholic balls.
Every culture which uses cycads has recognized their toxic potential, and this was implied, she added, by some of the native names given to them, like ‘devil’s coconut’ and ‘ricket fern.’ In some cultures, they were deliberately used as poisons. Rumphius (the Dutch naturalist whose name is now attached to the widespread Pacific species Cycas rumphii ) recorded that in the Celebes ‘the sap from the kernels…was given to children to drink in order to kill them so that the parents would not be hampered when they went to follow their roving life in the wilderness of the forest.’54 Other accounts, from Honduras and Costa Rica, suggested that Zamia root might be used to dispose of criminals or political enemies.
Nonetheless many cultures also regarded cycads as having healing or medicinal properties; Whiting instanced the Chamorro use of grated fresh seeds of Cycas circinalis as a poultice for tropical leg ulcers.
The use of cycads as food had been independently discovered in many cultures; and each had devised their own ways of detoxifying them. There had been, of course, innumerable individual accidents, especially among explorers and their crews without this cultural knowledge. Members of Cook’s crew became violently ill after eating unprepared cycad seeds at the Endeavour River in Australia, and in 1788 members of the La Perouse expedition became ill after merely nibbling the seeds of Macroza-mia communis at Botany Bay – the attractive, fleshy sarcotesta of these are loaded with toxic macrozamin.55 But there had never been, Whiting thought, a cultural accident, where an entire culture had hurt itself by cycad eating.
There were, however, examples of animals poisoning themselves en masse, unprotected by any ‘instinctive’ knowledge. Cattle which browse on bracken may come down with a neurological disorder which resembles beriberi or thiamine deficiency – this is caused by an enzyme in bracken which destroys the body’s thiamine. Horses in the Central Valley of California have come down with parkinsonism after eating the toxic star thistle. But the example which Whiting especially remarks is that of sheep and cattle, which are extremely fond of cycads; indeed, the term ‘addiction’ has been used in Australia, where some animals will travel great distances for the plants. Outbreaks of neurocycadism, she noted, had been recorded in Australian cattle since the mid-nineteenth century. Some animals, browsing on the fresh young cycad shoots (this would especially occur in dry seasons, when other plants had died off, or after fires, when cycads would be the first plants to reshoot new leaves) would get a brief, acute gastrointestinal illness, with vomiting and diarrhea – this, if not fatal, would be followed by complete recovery, as with acute cycad poisoning
in man. But with continued browsing on the plants, neurocycadism would develop; this would begin as a staggering or weaving gait (hence the colloquial name ‘zamia staggers’), a tendency to cross the hind legs while walking, and finally complete and permanent paralysis of the hind limbs. Removing the animals from the cycads at this stage was of no use; once the staggers had set in, the damage was irreversible.
Could this, Whiting and Kurland wondered, be a model for lytico? The idea was intriguing: fadang had been a common food before the war and, during the Japanese occupation, was used in much larger quantities, as other crops were requisitioned or destroyed. After the war, fadang consumption declined sharply because of the greater availability of imported wheat and corn flour – this, it seemed to them, could provide a very plausible scenario for the disease, why it had peaked immediately following the war, and steadily declined thereafter, an incidence which ran parallel to the use of fadang.
But the cycad theory was problematic on several grounds. First, there were no other known examples, outside Guam, of a chronic human illness ascribable to the use of cycads, despite their very wide and long use throughout the world. It was, of course, possible that there was something special about the Guam cycad, or some special vulnerability to it among the Chamorros. Second, the period of decades which might elapse between exposure to the cycads and the onset of lytico-bodig, if indeed the two were connected, was something which had no precedent in poisonings of the nervous system. All known neurotoxins acted immediately or within a few weeks, the time needed to accumulate to toxic levels in the body or for neurological damage to reach critical, symptomatic levels – this was so with heavy metal poisoning, as had occurred in the notorious Minamata Bay paralysis, with the neurolathyrism in India caused by eating the toxic chickling pea, and with the neurocy-cadism in cattle.56 But these seemed quite different from a poison which, while causing no immediate effects, might lead to a progressive degeneration of particular nerve cells starting many years later. No such delayed toxic effect had ever been described – the very concept strained belief.
