Grass pea and neurolathyrism: farmers' perception on its consumption and protective measure in North Shewa, Ethiopia.

Neurolathyrism in Ethiopia is caused by food dependency on grass pea (Lathyrus sativus L.). In the study area, a large proportion of the farmers are growing grass pea since it can withstand harsh environments. Socio-economic factors (poverty; lack of money to buy other food legumes) and environmental problems (such as water logging and frost hazards) influence consumption of grass pea. Most of the respondents have the idea that some chemical contained in grass pea causes a health problem. Different processing and preparation methods are used to prepare grass pea into different food forms. The major processing methods include washing and soaking, as the farmers apply these methods mainly because they assume that the chemical that causes lathyrism, scientifically known as ß-ODAP (ß-N-oxalyl-L-α,ß-diaminopropionic acid) is reduced through washing and soaking. The farmers adopt different strategies to avoid the problem of lathyrism such as avoiding consumption of grass pea in the form that they suspect to cause the problem, blending/mixing with other crops, applying different processing/detoxification methods. Since grass pea is consumed with a fear of lathyrism, future research should concentrate either on developing grass pea varieties with safe level of ß-ODAP content or improving the traditional/indigenous processing methods.

Studies on neurolathyrism in Ethiopia: dietary habits, perception of risks and prevention.

This study describes the correlation of traditional perceptions and dietary habits with the incidence of neurolathyrism to propose preventive measures. Therefore, 118 households of South Wollo and North Gondar (Amhara Regional State, Ethiopia), of which one third had at least one neurolathyrism affected member, were interviewed. Most of the affected families in this study had one neurolathyrism victim, being predominantly male and of younger age. The incidence among youngsters (boys and girls) was significantly correlated with the consumption of green unripe seeds (eshet), confirming this as a risk factor for developing neurolathyrism. The consumption of other popular grass pea preparations was not age related. Neurolathyrism patients did not attempt any medication as most people knew that neurolathyrism is incurable, but the consumption of grass pea was abandoned after developing the disease. The minority 'Woito' tribe was virtually unaffected. They were the only people reporting to consume fish which is rich in amino acids such as methionine and using metallic kitchen utensils in addition to clay pots. This observation points to the correlation between low neurolathyrism incidence and a better balanced diet as well as metallic kitchen utensils, suggesting a new approach for neurolathyrism prevention.

Unraveling the mechanism of ß-N-oxalyl-α,ß-diaminopropionic acid (ß-ODAP) induced excitotoxicity and oxidative stress, relevance for neurolathyrism prevention.

ß-N-Oxalyl-α,ß-diaminopropionic acid (ß-ODAP) is a plant metabolite present in Lathyrus sativus (L. Sativus) seeds that is proposed to be responsible for the neurodegenerative disease neurolathyrism. This excitatory amino acid binds to α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors and several lines of evidence indicate that ß-ODAP triggers motor neuron degeneration by inducing excitotoxic cell death and increasing oxidative stress. In addition, this toxin is known to disturb the mitochondrial respiration chain and recent data indicate that ß-ODAP may inhibit the uptake of cystine thereby compromising the cells' abilities to cope with oxidative stress. Recent work from our group furthermore suggests that ß-ODAP disturbs the cellular Ca(2+) homeostasis machinery with increased Ca(2+) loading in the endoplasmic reticulum (ER)-mitochondrial axis. In this review, we aim to integrate the various mechanistic levels of ß-ODAP toxicity into a consistent pathophysiological picture. Interestingly, the proposed cascade contains several aspects that are common with other neurodegenerative diseases, for example amyotrophic lateral sclerosis (ALS). Based on these mechanistic insights, we conclude that dietary supplementation with methionine (Met) and cysteine (Cys) may significantly lower the risk for neurolathyrism and can thus be considered, in line with epidemiological data, as a preventive measure for neurolathyrism.

Effect of methionine supplement on physical responses and neurological symptoms in broiler chicks fed grass pea (Lathyrus sativus)-based starter ration.

Starter feeding experiments of broiler chicks with raw grass pea (Lathyrus sativus L.) supplemented with different levels of DL-methionine were undertaken for 4 weeks to assess the toxicity of grass pea-based feed and to correlate it with neurological symptoms. Four hundred fifty day-old broiler chicks were divided into two groups and were given formulations containing 35% (ration I) or 98.5% (ration II) grass pea, respectively. Each ration included controls and treatments with added methionine of four different concentrations. Feed intake, weight gain and feed conversion efficiency (FCE) were much higher in ration I than in ration II and these parameters significantly improved by addition of methionine in both rations. Significant increase of neurological signs with higher grass pea intake and significant reduction of acute neurological signs with addition of methionine were observed. Tolerance for grass pea was enhanced with increasing methionine in the diet and with age. Despite a similarity in the initial intake, a significant (p0.05) increase in the final feed intake by the chicks with methionine addition was found in both rations. These results suggest that methionine can improve a grass pea-based diet for broiler chicks and especially can protect young chicks from neurological symptoms.

Neurolathyrism risk depends on type of grass pea preparation and on mixing with cereals and antioxidants.

OBJECTIVE: To study an array of household individual and dietary risk factors for neurolathyrism. METHOD: Case-control study using recent cases in a district highly affected by the recent neurolathyrism epidemic in Ethiopia: 108 households with cases and 104 households with no cases; 170 neurolathyrism cases, 370 intra-family controls and 170 community controls frequency matched for age and sex. RESULTS: A history of acute illness was associated with a two- and threefold increased risk of paralysis in community and intra-family controls, respectively. Soaking grass pea in water before cooking roughly halved the risk of neurolathyrism but cooking in clay utensils more than quadrupled it. Consumption of grass pea in the green unripe and boiled forms increased the risk 10 times or more. Mixing the food with gravy that contains condiments with antioxidant activity reduced it by a factor of 4. The consumption of grass pea mixed with cereals rich in sulphur amino acids was also highly protective, but the magnitude of the effect depended on the grass pea preparation consumed. CONCLUSION: Consumption of pure grass pea, especially in the green unripe and boiled forms, should be avoided. Communities at risk of neurolathyrism during famine crises should be encouraged to combine and use grass pea with cereals before the household cereal stock is fully depleted. Breeding programmes, alongside traditional attempts to reduce the toxin content, should enhance the content of sulphur amino acids and antioxidants in grass pea.

Food-aid cereals to reduce neurolathyrism related to grass-pea preparations during famine.

Neurolathyrism is a spastic paraparesis that can be caused by excessive consumption of the drought-resistant grass pea (Lathyrus sativus). Devastating neurolathyrism epidemics have occurred during major famine crises in various parts of the world. We investigated in a case-control study the effects of food aid on risk of paralysis. Risk increased with consumption of boiled grass pea (adjusted odds ratio 2.78, 95% CI 1.09-7.13 with cereals; 5.22, 2.01-13.55 without cereal) and raw unripe green grass pea (1.96, 1.16-3.31; p=0.011), but not with the fermented pancake, unleavened bread, and gravy preparations. In a correlational study there was an inverse relation between the number of new cases and the amount of food-aid cereals distributed per person. During famine, cereals and nutritional information should reach people before they have grass pea as the only food.

Neurolathyrism in Ethiopia: assessment and comparison of knowledge and attitude of health workers and rural inhabitants.

A cross sectional community based study was done in the Amhara Regional State of Ethiopia in 1999-2000 to assess and compare knowledge and attitude towards neurolathyrism among health workers and the rural community. A sample of 217 health workers selected by probability proportional to size and randomly selected 589 heads of household from a rural district were interviewed using pre-tested questionnaires. Neurolathyrism was widely known among the health workers and the community. More than half of community respondents associated the disorder with walking or lying on the straw and the stalks of grass pea. In a multivariate analysis. poor neurolathyrism knowledge among the community was associated with illiteracy and with presence of a neurolathyrism patient at home. Among health workers, contact with vapour or steam of grass pea foods was the commonest cause cited. In a multivariate analysis nurses had the poorest knowledge among the health workers. Depending on the subject, health workers and community respondents had more or less knowledge than the other. The prevailing recurrent adverse climatic conditions might promote grass pea as a 'friendly' crop to the poor peasants in marginal areas who otherwise rely on it only during times of food shortages and could increase the incidence of neurolathyrism. The poor knowledge among health workers and the community and the general neglect of neurolathyrism requires urgent intervention. Appropriate strategies for the dissemination of information education, and communication (IEC) are needed.

The epidemiology of lathyrism in north and central Ethiopia.

Lathyrism is a neurotoxic disorder caused by excessive, prolonged consumption of the hardy, environmentally tolerant legume, the grass-pea, Lathyrus sativus, which contains the neurotoxic amino acid beta-N-oxalylamino-L-alanine acid (BOAA). The disease develops after heavy consumption of grass-pea for over two months. It is uniformly manifested by a predominantly motor spastic paraparesis with varying degrees of disability. A door-to-door epidemiological survey for the disease using trained lay health workers was carried out in the major areas of northwest and central Ethiopia where L. sativus is grown. For security reasons, some of the other endemic areas wre not accessible for the survey. The survey involved a population of 1,011,272. A total of 3,026 affected persons were identified. The disease was found to be widespread in the northwest and central highland areas of the country. The prevalence rates ranged from 1/10,000 to 7.5/1,000. The highest prevalences were in North and South Gonder, and East and West Gojam. The male:female ratio of cases was 2.6:1; the females exhibited a milder form of the disease. The cultivation of L. sativus is increasing in Ethiopia, which makes the development of low-BOAA strains very important in order to control the high incidence of lathyrism, a crippling disease which affects the productive young members of the society.

The contribution of nutrition research to the control of undernutrition: the Indian experience.

Since diseases directly related to undernutrition are the major public health problems of India, nutrition research in the country has been largely directed towards elucidating their causes and identifying the most feasible methods for their prevention and control. This effort is an interdisciplinary exercise carried out in the laboratory, the clinic, and the field, with close interaction among biochemists, clinicians, and epidemiologists. Some of the identified solutions have found practical application; but, as in other areas of scientific endeavor, a gap exists between the acquisition of knowledge in the laboratories and its application in the field. Today, thanks to research efforts of the last few decades, we have the knowledge with which most diseases related to undernutrition can be prevented. Unfortunately, however, we do not always have the means of applying this knowledge under real-life conditions in the field. Even so, nutrition research during the last few decades has contributed significantly to the amelioration of undernutrition among poor communities in India.

[Chronic lathyrism. Protective effect of pyridinol carbamate on connective tissue lesions in the rat (author's transl)]. / Lathyrisme chronique. Effet protecteur du pyridinol carbamate sur les lésions conjonctives du rat.

The use of lathyric toxins (BAPN) in low dosage (1 g/kg/day) for a period of 8 weeks caused in the rat simultaneous changes in the skin and aortic connective tissues. In the skin. collagen tissue was dislocated and broken in fragments, the elastic tissue disappeared, the fibroblasts were vacuolized and presented evidence of injury. These lesions were comparable to those observed in human skin during ageing. The addition of pyridinol carbamate (PDC) to BAPN prevents the formation of lesions of the elastic tissue and of fibroblasts. When given after the cessation of the lathyrogen treatment PDC arrested the formation of the lesions and accelerated their regression.

Ultrastructural studies on the myocardial capillaries of the experimentally lathyritic rat, protective effect of certain flavonoids.

The ultrastructure of rat myocardial capillaries was studied in the course of experimental lathyrism. Endothelial cells were hypertrophic, with a sinuous profile of the plasma membrane facing the lumen and with a consistent increase of pinocytotic vesicles; the nuclei were irregular in shape; ATPase activity was no more demonstrable. Therefore, various and well distinct structural endothelial mechanisms seem to be primarily involved, causing an alteration of the dynamics of transcellular exchanges and of the permeability of the vascular wall. Simultaneous treatment with certain flavonoids, (O-(beta-hydroxyethyl)-rutosides and Na(+)-epicatechin-2-sulfonate), resulted in a less pronounced alteration and a more rapid recovery. The possibility of the existence of a common site of action of lathyrogens and flavonoids is raised in the discussion.