Cassava Cyanide Diseases & Neurolathyrism Network Issue Number 20, December 2012
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Working together to eliminate cyanide poisoning, konzo, tropical ataxic neuropathy (TAN) and neurolathyrism Cassava Cyanide Diseases & Neurolathyrism Network (ISSN 1838-8817 (Print): ISSN 1838-8825 (Online) Issue Number 20, December 2012 Contents Historical Awareness of Neurolathyrism, Historical Awareness of Neurolathyrism, and Cassava Toxicity and Cassava Toxicity ................................... 1 Most people studying lathyrism are likely to Acute cyanide poisoning from cassava: is have training in bio-scientific methods or in social it still common? ........................................... 4 science, yet there are considerable gaps of thinking International conference on “Recent and practice between different disciplines, e.g. from plant biologists to historians of food in human Trends in Lathyrus sativus Research” cultures. There are different approaches to what is (Hyderabad, India, November 8-9, 2012). ... 6 considered ‘well-founded knowledge’, and how it Neurolathyrism in Bidar and Medak may be established. This paper recognises such districts of South India ................................ 7 differences, and their relevance to knowledge- Residual Cyanide content In Cassava development in neurolathyrism, with brief Product of India ............................................ 7 comparison of cassava (manioc) and its toxicity. It also considers why a broader approach to knowledge is important, and whether historical CCDNN Coordinators: knowledge can be made useful to people who face Prof Fernand Lambein increased food scarcity, and are ‘below the radar’ of Ghent University, Institute for plant Biotechnology government attention. Outreach (IPBO) Review articles in lathyrism often begin with a Proeftuinstraat 86 N1, B-9000 Ghent, Belgium Phone: +32 484 417 5005 glimpse of history, citing ancient texts where E-mail: [email protected] or Lathyrus sativus seems to appear, or [email protected] archaeological reports of seeds found from antiquity. A recent review of South Asian research Dr. J. Howard Bradbury CCDNN honorary chairman and founder tabulates prehistoric remains of Indian pulses at 90 1 EEG, Research School of Biology, sites, 48 of which include L. sativus . Some are Australian National University from studies in the 1970s and 1980s, when Canberra ACT 0200, Australia advanced technology for identification and dating Phone: +61- 2-6125 0775 Email: [email protected] was hardly available. Across the sites where L. sativus was found, estimated dates extend from Editorial Board: J.P. Banea, J.Howard Bradbury, Julie Cliff, Arnaldo 2500 BC to 1600 CE. The earliest South Asian Cumbana, Ian Denton, D. Diasolua Ngudi, I. Ingelbrecht, textual evidence possibly indicating lathyrism also F. Lambein. N.L.V. Mlingi, Humberto Muquingue, Bala has a wide date range. That medical text, attributed Nambisan, Dulce Nhassico, S.L.N. Rao to Susruta, probably started as a collection on Country Contacts: surgery from several centuries BC, and was Cameroon: E.E. Agbor; expanded to its final form by the 5th century CE. D.R. Congo: D. Diasolua Ngudi and J; Nsimire Chabwine; Indonesia: A. Hidayat; The text itself, in Susruta’s Nidana-Sthana, 2.1 (On Mozambique: Anabela Zacarias; Breath and Wind), is not very clear: “Someone who Nigeria: M.N. Adindu and P.N. Okafor has tremors when starting forward or who seems to limp as he goes is to be known as ‘pea-lame’ Website: www.anu.edu.au/BoZo/CCDN (temporarily) (kalaya-khanja). The connections in the joints are 1 undone.” The Sanskrit specialist translator yuca, which the ‘New World’ islanders “first cut and cautiously notes that this “might conceivably” refer squeeze (for it is juicy) then they pound and cook it to lathyrism, yet kalaya is “normally taken to be into cakes ... they say the juice of yuca is more simply the common garden pea”, not the grass deadly than hemlock; if drunk, it kills on the spot pea2. Translators having surgical rather than {qui epotus illico perimit}. However the bread from philological expertise identify L. sativus in this the pulp, as everyone has experienced, is tasty and passage, without critical reservations3. good for you”11. Similar drawbacks occur in early European In Ethiopia, there is documentary evidence of evidence of Lathyrus sativus and textual reports of popular awareness of the harmful potential of possible lathyrism. Thirty European sites (amidst a Lathyrus sativus in the mid-16th century CE, when wider tabulation) with archaeological finds of likely the vernacular term transliterated as gwaya or seeds, date back possibly to 8000 BC; yet it guaia, having a ‘breaking’ or ‘paralysing’ sense, remains uncertain whether these were stray was given as equivalent for the Arabic gilban, weeds, or cultivated Lathyrus species4. A site in djilban etc, meaning L. sativus (or possibly some Greece, early in the 4th millennium BC, shows botanical close relative)12. In India, the Ain-i-Akbari grass pea “as frequent as pea and lentil”, asserted the “unwholesomeness” of kesari, “a suggesting cultivation5. The Greek medical school pulse, resembling peas, which is eaten by the poor” of Hippocrates, from the 5th to 4th centuries BC, in the late 16th century13. The same word, kesari or recorded that: “At Ainos, eating legumes khesari, is used now for the commonly eaten form continually, women, men, lost the power in their of L. sativus. It was used by Francis Buchanan, legs, and it persisted.” Greek translit.: “En AinO surveying in Central India in the 1810s, in the ospriophageuntes ksunecheOs, thEleiai, arsenes, earliest English medical description of the skeleOn akratees egenonto, kai dieteleon” (in impairment caused by lathyrism in India14. Yet Epidemics, book II, sect. IV: 3, with some variant conflicting evidence caused Buchanan not to readings)6. However, the vegetable eaten is believe that L. sativus was responsible. In both unclear, as is the time period involved. Several countries there is probably some earlier manuscript authors, using this text, curiously specify “all the evidence linking the plant and the risk, but there is men and women”, which would conflict with most very seldom clarity of botanical identification, or of lathyrism experience, where only a minority, mostly the resulting impairment. China had earlier printed male, are actually lamed by prolonged heavy use work combining careful descriptions and woodcut of the grass pea. The Ainos event is widely cited as illustrations, e.g. the Chiu Huang Pen Ts’ao (On early evidence of Lathyrus spp. causing lathyrism, Wild Food Plants for Use in Emergencies) by Chu yet scholarly views differ, and the evidence remains Hsaio, published in 1406 CE, including some uncertain7. Lathyrus species, and specific directions for Until recently, the antiquity of Cassava (manioc, preparation of some plants comparable to cassava or yuca) was also being introduced in Eurocentric in their toxicity15. academic works with vague mention of an Egyptian What use is ‘history’? Historical studies papyrus and the “poisonous properties of bitter provide a fuller background to ‘neglected diseases’, almonds” in Dioscurides (1st century CE). so that modern scientists may at least start with Meanwhile, in Central and South America, micro- whatever is already known and perceive some of fossil studies have focused more specifically on the complexities that misled or puzzled earlier pollen, starch grains and phytoliths, indicating “the thinkers. Abyssinia’s earliest detailed case histories domestication and spread of important native from a lathyrism epidemic, following the great crops” including maize and manioc (Manihot famine of 1888-1892, were published in 1899 by esculenta, Crantz), “between 10,000 and 5000 the Russian neurologist Friedrich Holzinger but, for years ago”8. This research field was already lack of historians pursuing them, they went missing maturing 30 years earlier, as shown by a more for a century, and remain uncited in modern demanding scrutiny of evidence in literature scientific literature16. Maybe this was an ‘own goal’ reviews9. Early Amerindian awareness of cassava by anglophone scientists who imagined that toxicity is assumed from ancient evidence anything worth reading must be published in suggesting various processing methods such as English; also Holzinger’s brief title, “On lathyrism”, “sun-drying, leaching followed by drying, and shows no link to Ethiopia (then known as soaking in running water ... drying and roasting”10. Abyssinia). Manuscript notes of cassava toxicity seem to have More remarkable is the disappearance of a reached Europe in 1493 from the first voyage of detailed scientific and anthropological study on Columbus, collated by Peter Martyr D’Anghera in lathyrism in Central India by the experienced Indian De Orbo Novo, published informally in 1504, 1507, Medical Service officer, Andrew Buchanan, and formally in 1511. Peter refers to the root crop commissioned by the [British] Government of India 2 and delivered in 190417. Major Buchanan made a positive gains (a readily available fodder crop, and close study of earlier and current literature in five a good famine safety-net when combined with languages, and of district officers’ reports feasible dietary supplements). Building the case responding to a specially commissioned lathyrism requires well-founded knowledge from many sides. survey. He toured rural areas for three months, References sampling villages with varying levels of lathyrism. 1 Fuller DQ & Harvey EL (2006) The archaeobotany of He cross-questioned families,