in*

Asnake Fikre

ForewordPrevailing misconceptions on the cause o f the crippling neurolathyrism

( ‘yeguaya beshita’ in Amharic) still misinforms the consumers o f grass pea

(Guaya) and the irreversible crippling keeps making victims. This handbook

tries to avail knowledge and experiences developed in the world 011

lathyrism research to the community facing this actual problem. Under the

four chapters it comprises an overview o f diverse research efforts and its

outputs including problem prevention in contemporary science. Out o f a

handful o f means to prevent the problem, some arc found with in the hands

o f consumers. With the available resources at hand, it is estimated that

knowledge dissemination to the consumers at the grass root level on the

correct facts concerning the crop toxicity would reduce the problem by

more than half. Grass pea. will be used further-on by the local name Guaya ,

has saved millions o f lives over many generations during crop failure and

droughts, but o f course it is also responsible for the subsequent crippling

disorder that affects a small proportion o f the population. The crop has the

stigma o f causing crippling disease and o f being an emergency food for the

very poor and research to improve yield and nutritional quality is lacking

behind in favor o f more fancy foods. Optimizing yield and quality o f the

crop has been insufficiently exploited as it is mostly produced in hard

climatic and/or poor edaphic exposure with negligible input by producers.

Researchers worldwide have focused on reduction o f one toxic substance

and overlooked the nutritional quality and the many useful environmental

qualities o f the crop. It is hoped that the brief presentation o f topics in this

bulletin will g ive an overview to concerned groups, incite development

practitioners and planners, instigate researchable areas and motivates

researchers to come up with workable means for the prevention o f lathyrism in order to make this unfair disease part o f history' and no longer part o f the

present.

U ^dh .200?

Grass pea

© EIAR, 2007 1999

Website: http://www.eiar.qov.et Tel: 251-11-6462633 Fax: 252-11-6461294 P.O. Box: 2003 Addis Ababa, Ethiopia

ISBN 9 9 94 4 -5 3 -1 5 -3

Copyediting and design: Page layout:Printing and binding: Distribution:Input to AGRIS:

Abebe Kirub Kidanemariam Hagos

Abesolom Kassa, Wudinesh Mamo, Miftah Hargeta and Messeret Kebede Aklilu Wube, Enanu Dagne, Bogalech Abebe, and Tnjalem Bizuneh Mintilu Tekle, Solomon Tsega and Amare Molla

ContentsForw ard iIntroduction 1G row ing ecology 5Production and utilization 9G uaya and lathyrism 15Research achievements 24References 29Acknowledgem ents V

Guaya [1]Introduction

Grass pea (Lathyrus sativus L.), also ‘guaya’ in Amharic, is among the more than 150 species in the genus Lathyrus.

It is a significant source of food, feed, and soil fertility restoration and income generation. By its hardiness to adverse environmental conditions it grows in marginal fertility farms, in lands exposed to recurrent drought, and tolerates to grow in lands with salinity problem. The lovely small gentian blue flowers make it one o f the beautiful crops and the seeds are advocated for prevention o f diabetes, to remove radioactive heavy metals from the body, and for giving strength to farm laborers.

Ethiopia as one o f the oldest growing homeland o f guaya is not only the largest producer (85%) and consumer, but also the most frequent victim of its toxicity in Africa (FAO, 1996- 2005).

Guaya stands as insurance crop in the unpredictably variable climatic conditions. The Central Highland Ethiopian farmers use this particular crop apart from its normal production to insure harvest from otherwise barren lands due to poorly draining Vertisols or marginalily o f farm plots or drought failed principal crop. It is planted in relay after the cereals to thrive on residual moisture. They also exercise rotational cropping o f Guaya with cereals to improve the soil fertility.

During the last several years, in Ethiopia, the overall production guaya has increased. Declining environmental conditions such as diseases and pest buildup on other principal pulses, total moisture scarcity, terminal stress, and deterioration o f physical structure and fertility of the soil and quota system of marketing contribute to the further expansion o f this crop.

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The other good reason contributing to the increase o f this crop could be the total annual expansion o f the cultivated area in Ethiopia by 6% (4% for Guaya alone) annually (Legesse et al., 2003).

Uniquely guaya grows in harsh environments where other crops fail. The crop as; potentially toxic food for those poor who have no other means to balance the diet and may suddenly develop irreversible crippling o f the legs. That is lathyrism.

Guaya is an ancient field crop since the Neolithicum that extends to about 6000 BC. As a funeral offering in the ancient pyramids o f the Egyptian Pharaoh’s it had a different connotation than being the survival food for the poor. In the In d ian su b -co n tin en t it was cu ltiv a ted as ea rly as 2000 BC and the crippling disease from over-consumption is described in old Greek and Indian literature o f 500 BC.

Nowadays, guaya is produced almost all over the world. The crop grows in North and East Africa, Southeast Asia, the Mediterranean coast Middle East, South and Central Europe, North America, South America, Canada and Australia. The ultimate goal o f production varies with the socioeconomic condition and living standard o f the region, from staple food to forage and from cropping system for sustainability of agriculture to marketing.

Ethiopian guaya accounting for 75.3% and 9 %in area coverage and 85.4% and 8% in production out o f Africa and the World respectively, stands between third and fifth in land cover among major pulses produced in the country and is mainly grown on Cambisol and Vertisols. West Tigray, South Tigray, East Tigray, North Gonder. South Gonder, North Welo, South Welo, East Gojam, West Gojam, North Shewa, West Shewa, and East Shewa are the major producer-consumer

Guaya [3]administrative zones o f Ethiopia. It is also found sporadically in Arsi, Bale, Hararge and the Southern Regional State areas. Food —> marketing—> fertility restoration/crop rotation/—* animal feed are the order o f production priorities from high to low in the main producer-consumer areas. Guaya is served most at special social occasions like in funerals in Welo.

Taxonomy and Morphology

Guaya or grass pea (Lathyrus sativus) is an annual vine resembling field pea (Pisum sativum) in growth habit, leaflets are long and grass-shaped. It is a much-branched sub-erect, straggling or climbing herbaceous annual; the stems are 0.6-9.0 m long and the leaves are pinnately compound with usually two leaflets (linear-lanceolate 25-150 mm long, 3-9 mm broad) (Campbell, 1997). The upper leaflets often have modified tendrils. Flowers are mostly solitary, auxiliary and are borne on peduncles 30-60 mm long; the corolla is 12-24 mm long and is reddish-purple, pink, blue or white in color. Pods are oblong, 2.5-4.0 cm long, flat and slightly curved and each pod has 3-5 seeds that are white, grayish-brown or yellowish and usually spotted or mottled in color and diverse in size and shape. It has a well developed taproot with rootlets covered by cylindrical nodules.

Cropping System

Guaya is sown late in the cropping season in monoculture often as precursor crop on previously cereal-based (tef, rice, wheat) farms. Ethiopian guaya, like any other food crop, is primarily produced for its seed as source of food for a variety of preparations. The straw, alone or mixed with cereal secondary stuff, is a good sources o f animal feed. It is an important

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legume in the rotational cropping system to improve the soil fertility status for the following crop. It is the crop best suited for the farming system relying on residual moisture in the soil, followed by chickpea (Cicer arietinum) as second best.

Guaya [5]Growing Ecology

Based on temperature, precipitation edaphic factor parameters Guaya grows in a number o f agio ecologies

and sub-agro ecologies in Ethiopian. The main growing agro­ecologies includes tepid to cool sub-moist plains and mountains and plateau (SM2-5), Tepid to cool moist plains (M2-1), Tepid to cool moist mountains and plateau (M2-5), Tepid to cool moist plateau (M2-6), Tepid to cool sub-humid plateau (SH2-6), Tepid to cool humid plateau (H2-6) and Tepid to cool sub-humid mountains (SH2-1) (MOA, 1998).

A factor often overlooked is the effect o f the environment on the toxin level in the seed. Poor soil, moisture stress, deficiency o f certain trace minerals or oversupply o f certain heavy metals can have dramatic effect on the toxin level in the ripe seeds. Even if Guaya is said to apparently withstand harsh and variable growth conditions, it must be born in mind that this fact is recognized at the expense o f yield and yield related components. That means the better the growing environment (cropping season) the better the yield performance and toxic levels and the contrary (Table 1). A general trend in Ethiopian condition is that ODAP decreases and yield increases from low altitude to higher altitudes which might be due to less thermal stresses and longer growing period for seed feeling. Even if there is information on ODAP increment along with higher light intensities like in the high lands, in Ethiopian context ODAP seem to decrease from low land to high land areas of production. In other words, when Guaya becomes a survival food during drought, the seeds may be considerably more toxic than during normal seasons hence it is very important to avoid or prevent the dependable over-consumption during such periods.

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Table 1: Variability of responses in yield and yield components and some qualitative parameters against changing environment in Ethiopian Guaya ecotypes (1999-2004)

Location Local cultivars used

Important ParametersMaturity days 100seed

w (g )Yield (kg/ha) ODAP(%) Protein (%)

Enewary

Ginchi - 5730 (1218-5065) 0.19(0.2-0.81) 24.4 (25.4-29.2)Molale - 3897(1218-5065) 0.28 (0.2-0.81) 23.6 (25.4-29.2)Adet - 4663(1218-5065) 0.36 (0.2-0.81) 24.4 (25.4-29.2)Enewary 8.0 (7.3-4.3) 3300 0.35 22.4D. Zeit 159 (151-160) 8.4 (8.4-10.3) 1040 (767-1335) - -

Molale

Ginchi * 1966 (577-3235) 0.28 (0.29-0.54) 26.0 (25.5-26.4)Molale - 1210 (577-3235) 0.32 (0.29-0.54) 26.3 (25.5-26.4)Adet - 1645 (577-3235) 0.50 (0.29-0.54) 24.0 (25.5-26.4)Enewary 10(9-15.1) 400 0.34 21.7

Debre Zeit Debre Zeit - 2298 (2164-2500) 0.37 (0.07-0.15) -

Debre Zeit 105 (104-108) 8.3 (7.7-9 6) 3833 (2267-4067) 0.27 (0.07-0.21) -

Akaki Debre Zeit 140 (132-149) 8.1 (7-9.5) 3903 (2293-4320) 0.18 (0.08-0.28) -

Alem Tena Debre Zeit 83 (81-92) 7.6 (7.3-9.2) 1247 (759-1444) 0.19 (0.10-0.22) -

Chefe Donsa Debre Zeit 139 (138-150) 8.6 (7.7-10.3) 3286 (2024-3458) 0.18(0.08-0.21) -

Denbi Debre Zeit 97 (98-108) 8.5(8.5-11.3) 961 (556-938) 0.25 (0.08-0.20) -

Range Values in parenthesis are that o f introduced genotypes planted along with the Ethiopian cultivars; - data unavailable ; Source: Asfaw el al. 2003.

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through the shoots to neutralize its osmotic activity and to maintain favorable osmotic pressure in the cell sap, the well developed and deep penetrating root system must play an important role to competitively extract the moisture deep down the soil column. Guaya grows also on soil environment with moderate salinity while it is sensitive to acidic soils.

Guaya [7]Climatic Variables

In Ethiopia, Guaya grows overlapping on the same agro- ecological domain as chickpea and lentil, predominantly in regions classified as semi-arid (warm winters and dry, hot summers with occasional rains). Currently 112,400ha of land is covered by Guaya accounting for 8.3% o f pulses (l,349,100ha) and 1% of the total cultivated crops (10,887,900ha). Its production shares 9.3% of the entire pulses (1,349,579 tons). About 98% o f Guaya in the country is produced in the main cropping season while some 2% is produced in Belg (short rain season).

This crop possesses considerable economic importance for the Ethiopian highlands where the altitude for the production ranges between 1900 and 2800 m. The mean temperature fluctuations during the normal growing season fall between 10°C and 30°C and annual rainfall ranging from 600 to 1200 mm but going much below minimum during periods o f drought spell or, as it is termed: under residual moisture cropping situation. It then appears to be the only green crop standing in the middle o f drought stricken parched surrounding fields and capably manage to bear at least poor seed harvest even in the worst droughts.

Edaphic Factors

The typical soil for guaya production is the black deep moisture retentive Vertisols and to some extent on Cambisols. These soils support a higher density o f agricultural settlers in the country. Vertisols areas, characterized by drier climate with the exception of evaporites, account for 10% (12.6 million ha) o f the total land area o f Ethiopia (Naod, 1993). In addition to its stress tolerance physiology such as the exudation o f manitol

Guaya [9]Production and

Utilization

Land Preparation

Plowing frequency using ‘Maresha’ varies between one and three where it could extend up to five for other pulse

crops. In many cases uniformity in soil structure cannot be achieved before planting because o f the compactness of the clay particles that cannot easily break as the moisture content dissipate. Equally, guaya planting on minimum cultivated plots, and un-uprooted grasses still standing alive to smother newly coming seedlings, diminish the envisaged pulse yield.

Planting and Crop Husbandry

Guaya, which grows on about 100 thousand hectares in Ethiopia, propagates exclusively by seed. It is planted in broadcast. Seed rate varies between 45 and 90 kg/ha depending on the fertility and preparation of the soil, method of cultivation, purpose o f cropping (food, forage or green manuring) and seed size and viability. In this aspect economical per unit plant density needs to be determined considering the underlying agro ecology, seed size, planting system and soil status. However, 10cm between plants and 40 cm between rows with 3 and 6cm depth is used in row planting on well-prepared experimental fields for research. On average one hundred seeds o f well-matured Ethiopian guaya, which is dominantly grayish-brown in color, weighs between 6.5 and 9.5g.

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In Ethiopia, the crop is neither inoculated nor fertilized although it is expected to leave fertilizing residue behind to the farmland beyond the ultimate harvest. Phosphorus is recommended in countries which produce guaya in relay cropping with rice.

Once the crop attains a thick mass over the entire surface it can smother out weeds. It is crucially necessary to either rogue-out smashing weeds or to carry out normal weeding while Guaya is at weak seedling period to compete. The trend o f ‘planting and come back for harvesting’ in guaya culture should be reconsidered. Field monitoring and pest assessment (Aphids, fungal diseases becoming important) must be undertaken for timely required action to increase guaya productivity.

Seed Production and Post-harvest Handling

Regardless o f the usual low moisture stress growing environment guaya is slow maturing. Seeds o f Guaya ripen in 3 14 -5 months and are harvested as soon as the leaves begin to turn yellow-brown and when pods are not over ripe as it dehisce and scatter the seeds. However, under optimal greenhouse conditions, seeds can be harvested after 2 !4 months. Guaya is harvested with sickle or uprooted by hand, left to dry for a few days in heaps and then threshed and winnowed.

Despite the rather unfavorable production management given by producers and hence in spite o f growing under yield- reducing factors that are virtually unchecked, Guaya is more productive than most o f the well managed pulses and thus cheaper. On average it gives about one ton per hectare where it elevates to four fold under optimized management situation

Guaya [11](DZARC, 2003). Higher productivity that could be stemmed partially from favorable management condition appears lower the toxin content of the seeds. Plump and matured seeds have less toxins store than otherwise insufficiently filled or immature seeds in the plant. Guaya does not have universal adaptation and equal responses to any production ecology, thus, its underutilized yield potential can still be exploited by adopting improved manageable factors.

The grain o f guaya is stored in noil-conditioned traditional granaries sealed with mud or cow dung or in clay sources. Nevertheless, guaya is much less attacked by storage pests compared to chickpeas or other legume grains. Important economic losses can be due to bruchid under some situation.

Utilization

FoodGuaya is the most promising sources o f essential amino acid Lysine-rich protein (Haque, 1997), minerals and calories for the vast and expanding food deficit population o f Asia and Africa. However, like other leguminacae family it is deficient in essential amino acids methionine and cysteine and has health affecting toxic free amino acid products. Guaya seeds contain 18.2-34.6% protein, 0.6% fat, 58.2% carbohydrate (about 35% starch) and less ash of~2.2%.

In Ethiopia, guaya is consumed in many forms (Table 2) such as green pea (eshet), roasted (kolo), boiled seed (nifro), unleavened bread (kita), pancake (Enjera), gravy (shiro), split cotyledon (kik), fermented grass pea pest (elbet), porriage (genfo) and seteto. This may imply that Guaya is a foodstuff of deep-rooted tradition o f Ethiopians. This days guaya Shiro is increasingly becoming common consumption for the popular

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recipe ‘shiro wot’ and found widely distributed even among non- producing areas in the country. Though it may vary depending on local habits and habitual consumer stake, special caution in grain processing o f guaya for food is taken such as frequent washing, boiling and used water avoidance to mention but some. Overall, it remains a bridge o f survival essentially for the majority o f resource deprived farming families between severe environmental calamities, often experienced in the country that reduce the agricultural harvest, up until next good cropping periods restoration.

Table2. Guaya foods, processing and consumption in Ethiopia

Food ingredients Processing Consumplion level: Gradation of lathyrism risk

Shiro wot /sauce/ Grass pea + other pulse sources + spice condiments

grass pea gravy is added as a major component of sauce making

Very High: low

Kik wot /sauce from split grass pea beans/

Roasted and split Grass pea seed + spice condiments

Sauce prepared using kik /split grass pea/ as major component

High: medium

Nifro /boiled grass pea seeds/

Grass pea seed + cereal source

Directly boiled, water decanted and consumed

Medium-high:medium

Kollo /roasted grass pea seeds/

Grass pea Commonly roasted after soaked /mild boiling/ and decanting the water

Low-medium: high

Kita/unleavenedbread/

Powder of grass pea + cereal source

Unfermented dough is baked with metallic or clay pans and consumed alone or with sauce

Low-medium: high

Enjera /pancake bread/

Powder of Grass pea + cereal

An over night fermented viscous dough is baked in day pans and used with S3uce

Low: very low

seteto Same as Enjera Made by hand a bit thicker than Enjera and with no 'eyes'

Very low: very low

elbet Powder of Grass pea + other pulse + spices

Roasted powder is well spiced and fermented for longer time /common in fasting period/

medium: low- medium

porridge Powder of grass pea+ cereal source

Powder is made into moistened baked dough and consumed with oily fats

Low: medium-high

Green pea Grass pea immature seeds

Hand picking in the farm field and consuming

Medium-high: very high

Source: Haileyesus el al.( 2005). Lambem, (7004)

Guaya [13]MarketingGuaya is the cheapest source of plant protein available in Ethiopia. In recent years, however, its income-generating power has been improving drastically. In some situations, away from harvest period, its price stands comparable to principal pulse crops like field pea, faba bean and chickpea. Guaya-Shiro is a typical source o f profit making for retail sellers by taking from its cheapest excess supplies to less available town destinations. There is an informal trans-boundary diffusion of its grain to neighborhood countries in merchandize. However, in the overall analysis, this low production cost crop has positive marketing potential in co-existence with the other higher input legumes, especially when considering the high price o f selected genotypes in health-food shops in Europe.

Soil ameliorationGuaya has great potential as a soil improving crop and as an alternative to commercial fertilisers. In symbiosis with Rhizobium bacteria it is a superior fixer o f atmospheric nitrogen (l 00 kg /ha) compared to many legume crops.

Nitrogen fixing begins in the top 30 cm, o f soil, about two weeks after emergence and reaches maximum activity between early and full bloom.

Guaya can be used as green manure or stay as groundcover until late harvest covering the soil by that protecting it against the cracking-desiccation and the mild wind erosion in the normal dry season. Its hardy deep penetrating root fetches water up to the subsurface rhizosphere facilitating microbial activities including the nitrogen fixing microbes like Rhizobium leguminosarum inoculants (Naod, 1993). Proper inoculation improves the legume growth, raises water use efficiency and reduces weed infestation significantly. By and

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large, it improves the soil condition for the coming crop that will perform far better after guaya was grown on the land.

FeedThe crop can be cut and fed green, or the standing crop may be pastured. It is not fit for silage but the straw could be a good source o f feed alone or in mixture with hay. Guaya is an important cheap source o f major feed ingredient in the small scale animal fattening industries. Bbulls, and small ruminants respond rapidly on feeding guaya. Hence, fetch higher market prices o f about 20-30% net profit. There is also potential as a good ingredient in the broiler ration formulation (Alemu et al., 2003).

Guaya [15]

Guaya and Lathyrismt j ~ l ecognition o f m an’s affliction by guaya toxin goes long

r \ b a c k to about two and half millenniums. Chemotaxonomic studies in the early 1960s established the presence o f several toxic amino acids such as the none protein amino acid toxin P-jV-oxalyl-L-a, P-diaminopropionic acid (P1- ODAP) in Lathyrus identified in 1964

Though Guaya has an immense agronomic potential even with minimal input, it caused several lathyritic epidemics in European, Asian and African countries. Historic outbreaks of this neurological crippling disease have been documented for Spain, Algeria, Ukraine, Russia, Germany, Italy, France, Syria, Ethiopia and in China. Victims of famine still face permanent paralysis from food of last resort in developing countries after its role as an important food source has been minimized in Europe and other developed nations by social awareness and legislative means. Now the most afflicted zone is located between 10° and 55° latitude and 15 0 and 105° longitude. In this flooding population zone are India, Bangladesh, Nepal, Ethiopia and NW China (Haque, 1997)

Lathyrism, traditionally known in Ethiopia as sehre or yeguaya beshita, is an irreversible neurodegenerative disease essentially manifested by spastic paraparesis of the lower limbs in man. T h e term "H u m an L a th ry ism sy n d ro m e" (H L S ) is co in ed to describe the rather diverse clinical and biochemical symptoms (including osteolathyrism) caused by L. Sativus (Tlaileyesus et al., 2005, Lambein et a i, 2004). It causes reduced mobility, scissor gait, turning-in o f the toes, stiffness, and semi-flexion o f the knee-joints. Sensory symptoms o f pain, numbness, and cramps may present but commonly at the on set victims suddenly feels weak and heavy in the leg when weight is

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exerted on them or after falling down or awakening from sleep. There is dragging o f legs, increased reflexes, and impaired ability to walk. According to virulence o f the disease and extent o f walking difficulty lathyrism is divided in to four stages (Table 3) (Haileyesus et al., 2005).

The causative element in Guaya is proposed to be an amino acid known as P-ODAP or [3-(-N-oxalyl)-L-2, 3-diaminopropionic acid]. Other Lathyrus species used as food have also occasionally been linked with neurolathyrism e.g. L. cicera, L. ochrus and L. clymenum. It is one o f the oldest diseases known to man and caused by over-consumption of Guaya food during an uninterrupted extended period potentially to the extent of accumulating (3-ODAP above a threshold level in the body to suddenly develop the crippling disorder overnight. So how much is taken up in the blood and over what length o f time, and how much is transported to Central Nervous System are crucial but as yet unanswered questions. In whatsoever the case, lathyrism is incurable just like AIDS, except the latter is a fast killer in most cases, while lathyrism remains a lifetime health problem. Lathyrism differs from rarely occurring osteolathyrism that is caused by consumption o f Lathyrus odoratus, or vegetative part or immature seeds o f Lathyrus sativus resulting in bone deformation (osteolathyrogenic) by affecting the cross-linking o f collagen during bone and connective tissue formation.

However, in Ethiopia lathyrism is a neglected disease that attracts little or no as such attention in health sector and appeared neither on the list o f the top 10 nor on top 20 diseases, where AIDS took the first position. There is neither formal nor strict advice given to consumers in periods o f drought and high risk o f lathyrism. even in areas where more than one crippling patient per family is common or in cases

Guaya [17]where this poverty linked disease seems inherited. In it’s commonly prevalence rate o f more 2% of every sever epidemics, the threat o f lathyrism never triggered any effort for national prevention campaigns, and the disease is still overlooked by media. So until recently, lathyrism remained neglected and unattended while in Ethiopia alone tens of thousands are estimated paralyzed and several millions o f fully exposed consumers are little or totally uninformed of the potential risk and are possible victims o f the crippling disorder. Although comprehensive surveys have never been done, in Asia and Africa there may be several hundred thousand people affected by this disease that cripples not only their legs but also their livelihoods grounding their socio-economic functioning in the already poor communities o f farmers surviving in a hand to mouth economy.

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Table 3: The four stages in epidemiology of lathyrism and ils typical clinical characterization

No-stick /mild/ = stage I

One-slick =stage II Two-stick=stage III Crawling =stage IV

Spastic gait with no stick and no Babinski sign, only ankle and joint movement, restricted by muscle spasm, rigid walk on ball of the feet, tilting pelvis leading to jerky movement, more visible vtfien running, it remains or pass to next stage

Severely affected patients with adductor spastic walk, scissors gait Ankle clonus and Babinski sign present one crutch/stick needed for maintaining body balance

aggravated condition of stage II, muscular stiffness and bending at knee joints spastic cross adductor gait need for two stick to walk. Ankle clonus and Babinski sign present severe muscular rigidity, patient need two stick for support

most sever casespatient develop chronic paraplegia in flexion of knee joints, extreme stiffness of lower limb and considerable bending of the knees (contracture), arms are strong and pyramidal signs present, can not walk upright hence crawfing

The Socio-economic Crisis of Crippling

Population pressure, ecological degradation, climatic changes, illiteracy and stagnant civilization may all have contributed to the cultivation and over-consumption o f the problematic Guaya as the only option for subsistence, particularly for the social strata o f poor economic and educational status. The geographical distribution o f the main production areas of

Guaya [19]Guaya overlaps with hot spot marks for lathyrism incidence in Ethiopia. The trend lathyrism incidence goes in an undulating fashion across years with peak occurrences in periods of persistent crop failure when only guaya survives. Lathyritic patients by no means can be as active and productive as they used to be. They often shift their activities to less strenuous duties or reduce to the status of beggar. Its limited progressive worsening after the onset further decreases the working efficiency o f the already handicapped. Often it is younger and the male breadwinner o f the family who is the most victim (Haileyesus et al, 2005) o f lathyrism and is then suddenly reduced to a totally dependent social and economic liability for the family and the community.

Lathyrism is both a social and a psychological disaster as patients’ equivalency in social wellbeing drops to marginal. Victims of Lathyrism are progressively reduced to human and social wreckage. Marriage is difficult and divorce is common for in either o f the two couples paralyzed. In rural communities, a victim of Lathyrism often becomes a social outcast and is branded as: ‘t/nable to run, f/nable to chase,£/nable to catch’. There seem to be cases o f suicide among lathyrism patients, something very unusual in Ethiopian culture.

Traditions, Misconceptions and Responses towards Lathyrism

Guaya producer-consumers are more affected than secondary consumers in towns/cities or elsewhere in Ethiopia. Producer- consumers have common knowledge, with scant ignorant, that lathyrism is caused by guaya but their reasoning varies. Some of the strong misconceptions are that the crippling lathyrism is caused by the steam emanating from boiling/boiled guaya, long

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contact with moistened straw or with flowering plants in the field or by consuming raw guaya with milk, and people try to avoid these situations as a way to prevent lathyrism. Uninformed people can not accept that the food that kept them alive should be toxic and the critical information for a nutritional survey is overlooked. Consumers often do not consider the amount o f guaya consumed or the period of high consumption or the way the Guaya seeds are prepared or in what portion with other foodstuffs.

There appears to be no treatment possible to recover from established lathyrism, neither by traditional nor modern medical practice. Traditionally physical therapy at the very early stages o f the disease has been found hopeful treatment. S p iritua l p o w er, d iffe ren t herb ju ic e with oral o r skin co n tac t administration, scratching about the skin and buttery food or animal bone soup feeding are common remedy practices undertaken by the indigenous people however with minimal or null recovery.

Preventions against Lathyrism

Research to eliminate the toxic properties from guaya started early in the 20th century, the low level o f essential amino acids, the imbalance o f micronutrients and the presence o f a toxin were all studied. The discovery o f the neuroexcitatory amino acid ODAP in 1964 has directed almost all research to the understanding o f the toxic action o f ODAP. However, even now the understanding o f the etiology o f the disease is far from complete. A major draw back is the absence o f a practical animal model, where the disease can be induced by the administration o f the toxin or the feeding o f Guaya. Without such an animal model, the safety of low toxin varieties can not be proven unequivocally.

Guaya [21]Four decades o f ODAP research did not prevent the recent epidemic o f lathyrism in Ethiopia. A systematic report o f its type that give clue between man’s intake and response o f grass pea was evidenced from a remarkable epidemic o f lathyrism occurred during the Second World War among prisoners in 1942, which were given grass pea for food. However, these epidemics also have learned that a number o f factors can aggravate the risk or can be protective factors against the development o f lathyrism. Some o f these recent findings support old views that mixing grass pea with sufficient cereals or with antioxidant containing spices and herbs can help to prevent lathyrism (Lambein et al., 2001).

Breeding studies into the crop have outstandingly reduced the toxic content from a potent level to as small as negligible but this low level was not stable and dependant o f environmental factors such as drought and the content o f minerals in the soil. The reduction o f the toxin also does not solve the deficiency of essential amino acids or the variable content o f micronutrients that is dependant on the soil. Because guaya is often grown without any inputs on soil that has been exhaustively used for other crops that may have depleted the micronutrients, the plants often grow under marginal conditions o f fertility that further disturbs the balance o f micronutrients in the seed. Even under such marginal circumstances, the plant can yield seed to help the survival o f the hungry during an extended dry spell (Asgelil et al., 1994).

If the consumption o f guaya remains limited and less than half o f the total diet supplemented with cereals that are richer in the essential amino acids deficient in Guaya, the chances to develop lathyrism are still minimal. Uninterrupted consumption o f guaya as main food during several months has

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to be avoided at all times, it is especially risky when the environmental conditions make other crops fail.

Success Stories

BanBy imposing legislation against its production and marketing, Europeans have successfully eradicated lathyrism as their economy and education have worked alongside to improve the variation o f nutrition. However, India and Nepal who more recently imposed a ban on trade o f grass pea still see high production and consumption o f grass pea. This does not mean that guaya is no longer in use in the West where grass pea is still being produced in small scale by farmers o f southern and central Europe and even offered in health food shops but consumption is low in an otherwise balanced diet.

DiversificationIn Ethiopian context, lathyrism is not a health problem o f either city' people or cereal dominated crop production-consumption areas where in both cases guaya accounts for low proportions in the apparently more di%'erse daily diet o f the family. Unquestionably the better the economy the stronger it gets to fight lathyrism incidence.A ltern a tiv e cropping: as with the introduction o f new crops such as rice in places o f the used to be common grass pea areas, like happened in huge marsh land o f the Fogera plain in Gonder, Ethiopia, could have remarkable potential in shifting the food habit that would be accompanied with less risk o f lathyrism.

The h ea lth p rob lem ‘lathyrism? th e cause and p o ss ib ilit ie s o f d evelop m en t: the small metabolite B- ODAP present in guaya, chemically an analogue o f the natural

Guaya [23]neuroexcitant glutamic acid, itself a protein amino acid, has been proposed as the cause o f the irreversible crippling (Lambein et al., 2004). This same molecule is also present in the health promoting ginseng where it is considered to have hemeostatic effect known as gencichine. If ODAP reaches the brain it can overexcite a sub group o f glutamate receptors and trigger neurophysiological reactions including release of glutamate and production o f nitric oxide (NO). This contributes to reactive oxygen species (ROS) and oxidative stress which can lead to neurodegeneration. Apparently the upper motor neurons are particularly sensitive to this stress and their dysfunction may be the cause o f the symptoms o f spastic paraparesis seen in neurolathyrism (Lambein et al., 2001).

Lathyrism can also be an indirect consequence o f natural and human made disasters, when crops are destroyed and when poverty and illiteracy are socio-economic risk factors for the incidence. Continuous consumption o f the cheapest food available without interruption or admixture with other foodstuffs that balance the essential nutrients for about or more than two months can trigger this crippling disease, attacking by preference the hardworking young men. It is also found that strenuous exercise, diarrheal episode and febrile illness, malnourishment, illiteracy and sex aspect (males are more attacked than females) are epidemiological risk factors for lathyrism (Lambein, 2 0 0 1 / In the shadow of lathyrism health problems o f secondary importance like asthmatic attacks related to Lathyrus sativus Hour inhalation has been reported.

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Research Achievements

S ince its identification research has been focusing towards the reduction or complete removal o f B-ODAP from the

seeds. Through breeding lines with dramatically lower ODAP levels down to 0.01% were developed when the original wild type varieties could have up to 1.5%. Ethiopian guaya has ODAP range between 0.20 and 0.55 percent o f seed fresh weight (DZARC, 2003). Exhaustively employed conventional breeding techniques, however, could not completely eradicate biosynthesis of ODAP, to this end, now a paradigm shift to biotechnological techniques is under way.

In the plant the ODAP concentrations vary widely in different organs with the highest occurring in the embryo, followed by cotyledon, seed coat, stem, lea f and root in decreasing levels. The growing environment and food processing treatments have substantial impact on the concentration o f ODAP in the final dietary product. ODAP increases up to a 200% (doubling) to location variability effect, up to 125% to delayed planting date and up to more than 200% to micronutrient condition o f the soil in Ethiopian context (Asfaw et al., 2003). With the effect o f heavy metal pollution can go up to 600 %.

From representative production areas it was found that the reduction in concentration due to processing can be a significant percentage in reference to the unprocessed form. Various guaya preparations contained the following concentrations. Recalculated percentage reduction in ODAP of the food stuffs in reference to raw Guaya has been indicated in brackets. The concentration ranged 480-780mg/100gm in raw, 228-412mg/100g (53-47%) in gravy (shiro), 221-443mg/100g (54-44%) in spited cotyledon (kik) and 72mg/100g (89%) in sauce (shiro wot). Green unripe pea or roasted or boiled guaya

Guaya [25]consumption has a higher toxicity than any other fermented or mixed preparations such as gravy (shiro wot) where antioxidant containing herbs and spices are added such as onion, garlic, and ginger. Twenty-four hours soaked guaya with adequate renewing o f water also has dramatically reduced toxicity despite the leach out o f other important amino acids along with the toxic free amino acid.

Guaya Foods

A deal to manage guaya toxicity based on knowledge would make a difference to go out o f lathyrism.

Modify Cropping

Late planting is associated with low moisture stress and this aggravates ODAP buildup in the sink o f the crop at the expense o f the yield; hence the earlier planting is found to be better for lower toxicity.

It has been indicated that fertilization has some thing to do with ODAP. Effect o f nutrients on toxicity is becoming evident. Zinc treatment seems to contribute in ODAP synthesis repression. However, in their counter balance presence Phosphorus and Iron are known to antagonize zinc and increase the toxic level. Even then optimization o f the rate based on soil analysis is not that clear yet. Hence, optimization among macro and micronutrients found to give promising result, guaya is traditionally the crop for adverse season and marginal land and with no inputs. Growing the crop under more optimal conditions can make it less toxic and more productive as the total product in the plant would distribute among plump and loads of seeds. Agricultural practices that increase the yield o f

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the crop seemingly appeared also to decrease the toxicity o f the crop, although more research in this direction is needed.

Low Toxin Varieties

Since the discovery o f a neuro-excitatory amino acid ODAP in guaya seed, efforts to develop guaya varieties free o f this toxin have not yet succeeded. The very complex environmental effects on the physiology o f the drought tolerant plant and on the biosynthesis o f this toxin result in a high variability o f the plant and o f the toxin content. Low toxin varieties developed in Canada and elsewhere did not keep this low toxin character when grown in different environments. The first low toxin variety, Pusa-24, was released in India in 1974 and other releases followed.

Although it is at its very beginning in Ethiopia, low toxin Guaya varieties are in production in other parts o f the world. Recently a low toxin variety called WASIE was released in DZARC for extensive production. Under cautious recommendation management they are referred to as safer to produce for consumption following thorough processing and mixing procedures. However, the issue o f out-crossing contamination (-27% ) and environmental threat need to be considered and designed by production specialists.

Processing

Any processing attempt on guaya food contributes to toxicity reduction even if one mechanism is more effective than the other. Unripe green pea is the most toxic and should be avoided by all means. Children are most exposed as they eat the green seeds as snack during field stay with the herd or walking. Consumption o f raw seeds in any form, roasted and boiled

Guaya [27]seeds should be limited as much as possible. Information campaigns and literacy campaigns need to reduce ignorance. It is the ingestion of the seed and not any form o f contact with guaya that so far proved to induce the disorder. Despite any guaya food processing attributes to decrease the toxin level by certain amount, pre-processing like long soaking (>18hrs) and fermentation have significance role. When legumes are properly soaked and germinated, their nutritive value increases greatly and the anti- nutritional factors such as enzyme inhibitors, toxic amino acids and other anti-nutrients are greatly decreased to insignificant levels. Mixing guaya food preparation with condiments such as onion, ginger as in gravy and gravy sauce or keep in proportion below 1/3 in cereal mix, richer in essential amino acids, are among outweighing principles to use the crop safely (Haileyesus et al., 2005).

Awareness

Lathyrism nowadays is endemic in isolated and inaccessible rural villages and remains the disease o f the resource poor. Also widespread misconceptions that contact with the seeds, the flowers or the cooking water rather than the consumption are the cause o f the disease; contribute to its higher incidence. The more traditional, the less literate and the poorest segment o f the society dominate the numbers o f lathyrism victims. Awareness increasing, so far hardly practiced, about the real cause o f the disease and knowledge buildup on its characteristic behaviors could establish guaya as a useful and healthy part o f balanced diets. Indoor detoxification strategy helps to reduce the toxin, but mixing with sufficient other foodstuffs richer in essential amino acids, such as cereal grains and onions are more important for food safety.

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Modify Home Consumption and Empower Marketing

Diversification o f food sources apparently implies satisfaction of nutrient requirement for health personality, hi the philosophy o f complete food, the nutritional quality in required amounts o f carbohydrates, proteins, minerals and vitamins sources should be maintained in a balanced manner. Like practiced with other produces, guaya should come to the market to fetch equivalently other crop produces hence would facilitate home food diversification and lathyrism protection.

Enabling the Disabled

The quality of life and the social ground o f lathyritic people soon deteriorate after onset of the crippling and often become social outcasts. For this segment o f the society; schooling, skillful training, marriage, social position and the like are less accessible or a bigger challenge. After all, if crippling is judged inability, socio- traditional pressure is discouraging. However, these should be turned around and development workers and the authority should prove their key importance by giving due involvement consideration for the crippled at planning, designing and implementing any development program in the area. Irreversibly sacrificed, provided proper arrangement, they can however become devoted teachers deserving due respect from whom others can learn not to fall the same crises.

Future Harvest

Guaya is used to be proposed as crop o f the future implying the world will get more problems o f limited water resources and more salinity, for which condition grass pea is better armed

Guaya [29]than almost any other crop. The crop has saved uncounted human lives in the past, many more than it paralyzed in the famine sfticken areas o f the world. No question about its importance, but making optimal use o f it in confidence is the challenge kept the bright future handicapped by the stigma of its toxicity.

There is still room to make improvement in the crop using conventional or the contemporary biotechnological approach, as enriching its content o f deficient amino acids and optimizing its amino acid profile, stabilization o f toxin, improving the yield and better use o f micronutrients. In its generation age challenging research, apart from the remarkable gains basic prospective grounds have been laid down that facilitate move ahead. The successful development of an entirely safe high protein food staple resistant to environmental stresses such as drought, flood and fertility marginality is potentially ground­breaking to provide a new crop option for global agriculture.

References

M inistry of A griculture (MoA). 1998. N atural resource m anagem ent and regulatory departm ent. A ddis Ababa, Ethiopia.

Alemu Yami, Tadelle D, N igusie D, W endim eneh E and fedlu H.2003. The effect of increm ental replacem ent of N ouge (Guizotia abyssinica) cake in diet by Grass Pea on perform ance of roilers.. Proceedings of the second w orkshop on pulses research in Ethiopia. Hilton, A ddis Ababa

Asfaw Telaye, W ondafrash M ulugeta and Lijalem K orbu .2003. Breeding Grasspea, Fenugreek and Lupine for w ide adap ta tion in Ethiopia. Proceedings of the second w orkshop on pulses research in Ethiopia. H ilton, A ddis Ababa

[30] Asnake Fikre

Asgelil D, W olde Amlak Araya, Bekele H unde, Regassa Ensermu. W asie H., Yeshanew A., Asm are Y. and W ondim agegn Siyum. 1994. The status of grass pea (Lathyrus sativus) research and production in Ethiopia. In: Birhanu M .Abgaz, Reda T /H aim ano t, V.S.Palmer and P.S.Spencer.1986. N utrition, N eurotoxin and Lathyrism: The ODAP challenge. Proceedings of the second International Lathyrus/Lathyrism conference in Ethiopia. New york; the third W orld Medical Foundation, pp44-59.

Cam pbell Clayton G. 1997. Grass pea. Lathyrus sativus L. Prom oting the conservation and use of underutilized and neglected crops. 18. Institute of P lant Genetics and Crop Plant Research, G atersleben/In ternational Plant Genetic Resources Institute, Rome, Italy.

Legesse Dadi, H ailem ariam Teklewold, A den Aw- H assan, Alim Abdel M oneim and Geletu Bejiga. 2003. The socio-Economic factors Affecting grasspea consum ption and Includence of Lathyrism in Ethiopia. Integrated N ational Resources M anagem ent Research Report Series, No.4. ICARDA, A leppo, Syria, P.15

Lam bein F, D elphin Diasolua N gudi, Yu-Haey Kuo.2001. Vapniarca revisited: Lessons from an inhum an hum an experience. Lathyrus Lathyrism N ew sletter 2 (2001

Debre Zeit A gricultural Research Center. 2003. A nnual research report Debre Zeit.

FAO. 1996-2005. Crop production statistics.Lambein F. 2004. Advise into safe utilization of Grass pea (Lathyrus

sativus). Flier (translated to Amharic). G hent UniversityHaileyesus G etahun, F.Lambein, M. V anhoorne and P.Van der

Stuyft. 2005. N eurolathyrism risk depends on type of grass pea preparation and on mixing w ith cereals and antioxidants. Tropical M edicine and International Health. V10: No 2 ppl69- 178.

Haque.R.1997. A study on the effect of nutritional and agroecological factors on the accum ulation of neurotoxin JL-a, p-Diamino Propionic Acid (ODAP)l and other am ino acids in Lathyrus sativus (Khesari) aim ed at repressing its toxic synthesis. PhD desertation. Gent University

N aod Kebede. 1993. Effect of environm ental factors on the toxicity of Lathyrus sativus (Guaya), A stress tolerant crop cultivated on the Ethiopian vertisols. MSc Thesis. U niversity of Ghent.

Guaya [ 3 1 ]

AcknowledgmentsThe author would like to thank Ethio-Belgian Lathyrus Nutritional Improvement Project (2004-2008) for generously allocating resources for publishing the document; Prof. F. Lambein, Dr. Seid Ahmed and Mr. Lijalem Korbu are acknowledged for their editorial work and valuable inputs to enrich the content