TABLE 11 - Daily per caput nutrient supply in 36 countries with rice as staple

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Source: FAO Statistics Division, 1987-89 average.

General nutritional status

Table 13 provides information on some important indicators of overall nutritional status for 34 rice-consuming countries (UNICEF, 1991). It clearly indicates that in most of these countries the incidence of low birth weight, infant mortality and mortality under five is high and the prevalence of moderately and severely underweight children is alarmingly higher. The life expectancy is also low. About half the people in South Asia and sub-Saharan Africa receive inadequate energy for an active working life. Some 470 million undernourished people live in South Asia. All these data are a reflection of the poor general nutritional status of the population.

Protein-energy malnutrition

Protein-energy malnutrition still prevails widely in many rice-consuming countries. The low-income developing countries among the group are primarily and seriously affected. PEM is manifested by widespread growth retardation among preschool children. For example, nutrition surveys have shown combined prevalence rates of 71 and 17 percent for moderate and severe underweight among preschool children in Bangladesh and the Philippines, respectively. In many other rice-consuming countries, particularly India, Laos, Madagascar, Nepal, Sierra Leone, Sri Lanka and Viet Nam, PEM is a major factor directly or indirectly contributing to high under-five mortality.

TABLE 12 - Average daily energy and protein intake in selected riceconsuming countries

Source: FAO country profiles and national nutrition surveys.

Vitamin A deficiency

Vitamin A deficiency is widespread in rice-consuming populations of tropical Asia (DeMaeyer, 1986). The most severely affected countries include Bangladesh, India, Indonesia, Myanmar, Nepal, the Philippines, Sri Lanka end Viet Nam. Vitamin A deficiency is also a problem in northeastern Brazil.

TABLE 13 - Nutrition indicators for selected rice-consuming countries

^a Listed in descending order of under-five mortality rate.

^b Annual number of deaths of children under five years of age per 1000 live births.

^c Annual number of deaths of children under one year of age per I 000 live births.

^d 2 500 g or less.

^e Below minus two standard deviations from median weight for age of reference population.

^f The number of years new-born children would live if subject to the mortality risks prevailing for the cross-section of population at the time of their birth.

Source: UNICEF, 1991.

Although it is difficult to determine the exact number of new cases of vitamin A deficiency and xerophthalmia occurring globally each year, available data from Indonesia indicated an annual rate of 2.7 per 1 000 children, leading to an estimate of 63 000 new cases annually for Indonesia. If a similar rate is applied to Bangladesh, India and the Philippines some 400 000 preschool children in these countries are likely to develop active corneal lesions resulting in total or partial blindness. It has been further estimated that worldwide some 3 million children under 10 years of age are currently suffering from blindness from xerophthalmia, about I million of whom are in India. In addition, countless children not presenting active signs of xerophthalmia are vitamin A depleted, a condition associated with decreased resistance to infectious diseases and increased mortality and morbidity.

Nutritional anaemias

Nutritional anaemias, mostly from iron deficiency, are widespread among rice-consuming countries. The causes are low dietary intake of iron, low biological availability of iron from food (Hallberg et al., 1977), blood loss caused by intestinal parasites, particularly hookworm, and unfulfilled increased demand associated with rapid growth and pregnancy.

Anaemia is a condition diagnosed when haemoglobin level is below a set level suggested by the World Health Organization (WHO), depending on the age, sex and physiological condition (with adjustments necessary for high altitudes). AWHO estimate for 1980 (DeMaeyer and Adiels-Tegman, 1985) indicated that about 1 300 million of the 4 400 million people in the world suffer from anaemia and 1 200 million of these are from developing countries. Young children and pregnant women are most affected, with global prevalence rates estimated at 43 percent and 51 percent respectively, followed by school age children (37 percent), women of reproductive age (35 percent) and male adults (17 percent).

The highest overall prevalence of anaemia in the developing countries occurs in South Asia and Africa. The prevalence rate of anaemia in South Asia (DeMaeyer and Adiels-Tegman, 1985) was estimated to be 56 percent in children up to 4 years of aye, 50 percent in 5- to 12-year-old children and 32 percent in men and 58 percent in women 15 to 59 years old. A higher rate (65 percent) was reported for pregnant women. Slightly lower rates were reported for East Asia, excluding China.

Estimates of anaemia from folate and vitamin B12 deficiency are not known, but this type of anaemia is reported to occur, particularly in India. Dietary patterns suggest increased risk in parts of Southeast Asia, but data are inadequate to confirm this.

Anaemia is an important cause of maternal mortality associated with childbirth. In addition, in adults it lowers work performance and has been linked with reduced immune competence and resistance to infection. Mild anaemia may also have far-reaching effects on psychological function and cognitive development.

Iodine deficiency disorders

Iodine deficiency disorder (IDD) is prevalent in many rice-eating populations, particularly in mountainous regions in Brazil, China, India, Indonesia and Malaysia, where the iodine content of soil, water and food is generally low

(Chong, 1979; Khor, Tee and Kandiah, 1990). IDD is also prevalent in Bangladesh because frequent flooding washes the iodine from the soil. It has been estimated that about 800 million people worldwide are at risk of IDD (United Nations, 1987). Nearly a quarter of those at risk have goitre and over 3 million are estimated to show overt cretinism. Most people at risk are in Asia, including 300 million in China and 200 million in India.

In areas with very high prevalence of iodine deficiency goitre may affect over 50 percent of the population and occurrence of cretinism may vary from I to 5 percent. An additional 25 percent may suffer from measurable impairment of mental and motor function. In some remote areas of the Himalayas IDD prevalence of 30 percent has been recorded.

Iodine is essential for normal growth and foetal development and for normal physical and mental activities in adults. Apart from overt signs of IDD, iodinedeficient populations may suffer from a variety of consequences that include reduced mental functions, widespread lethargy, increased stillbirths and increased infant mortality.

Thiamine and riboflavin deficiency

Thiamine and riboflavin deficiencies still exist in many parts of Asia. Beriberi is a characteristic disease of rice-eating communities, particularly when polished rice is consumed. It is rarely seen in communities where rice is eaten parboiled or undermilled. The replacement of hand pounding by machine mills in rural areas has aggravated the problem (Chong, 1979). Thiamine and riboflavin availabilities are lowest in Far Eastern diets (FAO, 1990b), (Table 10).

Clinical and experimental studies have suggested that the development of clinical manifestations of beriberi requires a thiamine intake below 0.2 mg per 1 000 kcal. Biochemical signs may be present at intakes as high as 0.3 mg per 1 000 kcal.

Over the years beriberi has tended to disappear as economic conditions have improved and diet has become more varied. Although the prevalence of clinical cases of apparent beriberi in adults has fallen, in many places beriberi in breastfed infants is seen sporadically in some populations. For example, some rural lactating Thai mothers who only eat rice and salt post partum and who restrict nutritious food are prone to develop thiamine deficiency. The low thiamine content in their breast milk predisposes their breast-fed infants to beriberi.

Angular stomatitis, a clinical sign often attributed to riboflavin deficiency, is also frequently seen in young children, pregnant women and lactating mothers in rice-eating populations in Bangladesh, India and Thailand. In Thai villages riboflavin deficiency has been reported to coexist with thiamine deficiency (Tanphaichitr, 1985).

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