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Nutrition of infants and young children in China
NUTRITION RESEARCH, Vol. 8, pp. 105-117, 1988 0271-5317/88 $3.00 + .00 Printed in the USA. Copyright (c) 1988 Pergamon Journals Ltd. All rights reserved.
Nutrition of Infants and Young Children in China David L. Yeung, Ph.D. Head, Heinz Institute of Nutritional Sciences Shahe, Yang Tang, Guangzhou People's Republic of China
ABSTRACT
A p p r o x i m a t e l y 20 million infants are born in China annually. During the neonatal period most of the infants are b r e a s t f e d and they grow at rates similar to infants raised in i n d u s t r i a l i z e d countries. Past three months of age, p a r t i c u l a r l y in urban areas, many infants are w e a n e d from the breast and are given foods of low n u t r i t i o n a l value. C o n s e q u e n t l y suboptimal growth, and iron d e f i c i e n c y are prevalent. Vitamin D - d e f i c i e n c y rickets and zinc d e f i c i e n c y are also evident. Other n u t r i t i o n a l p r o b l e m s such as p r o t e i n - c a l o r i e malnutrition, d e f i c i e n c e s of vitamin A, calcium, and the B-vitamins have been r e p o r t e d but no statistics on the p r e v a l e n c e of these problems are available. Infant o b e s i t y is an e m e r g i n g problem. S e l e n i u m and iodine d e f i c i e n c i e s have been controlled. Child health and welfare are e m p h a s i z e d in public health services in China, but the k n o w l e d g e of infant feeding p r a c t i c e s needs to be improved. Key words:
Breastfeeding, feeding practices, nutritional deficiences, infants, preschoolers
growth,
INTRODUCTION China is g e o g r a p h i c a l l y the third largest country in the world. It o c c u p i e s 9.6 million square k i l o m e t e r s or one fourteenth of the total land area of the world. It has the largest population, close to one billion, which is more than o n e - f i f t h of the world p o p u l a t i o n (i). Eighty percent of the p o p u l a t i o n live in rural areas and 20% urban areas. C o r r e s p o n d i n g address: H.J. 5650 Yonge St., North York,
Heinz Company of Canada Ontario, M2M 4G3
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Ltd.,
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In 1949 when the present government took control, the p o p u l a t i o n in China was about 400 million. By 1980 it had r e a c h e d one billion. This rapid growth was the result of (a) high birth rate, (b) d e c r e a s e d infant m o r t a l i t y and (c) increase in life span from 32 years in 1949 to 69 years in 1982 (2). The latter remarkable achievement could be a t t r i b u t e d to the more equitable d i s t r i b u t i o n of daily n e c e s s i t i e s and improved public health p r e v e n t i v e services. In 1979, the central authorities in China a n n o u n c e d the "One Family One Child" policy (2). The aim was to c u r b the rapid p o p u l a t i o n growth, to improve the national economy, to raise the standard of living and to achieve the four m o d e r n i z a t i o n p r o g r a m s in agriculture, industry, defense and science and technology. In spite of the stringent birth control policy, the annual birth rate in China today is close to 20 million. The purpose of this paper is to p r e s e n t an o v e r v i e w on child care, infant feeding p r a c t i c e s and p r e v a l e n t n u t r i t i o n a l problems in infants in China today. The i n f o r m a t i o n p r e s e n t e d is based on a v a i l a b l e literature, clinical impressions of health p r o f e s s i o n a l s in China and o b s e r v a t i o n s made by the author during his frequent visits to China.
CHILD CARE In China, women are e n c o u r a g e d not to become p r e g n a n t until 3 to 5 years after marriage and not before 24 years of age. Even then, a woman may become p r e g n a n t only by p e r m i s s i o n based on a quota system, from the p o p u l a t i o n control committee in the community to which the woman belongs. Once p e r m i s s i o n is granted and p r e g n a n c y is established, the mother receives c o m p r e h e n s i v e a n t e n a t a l care (3). The p a r e n t s attend prenatal classes where child care, n u t r i t i o n and other pertinent subjects are taught. Postnatally, child health services include home visits for care of newborns and routine physical e x a m i n a t i o n s in local Maternal and Child Health Centers. Preventive services in growth m o n i t o r i n g and i m m u n i z a t i o n are also p r o v i d e d in these centers. M a t e r n i t y leave is generous. M a t e r n i t y leave with pay is n o r m a l l y 56 days p o s t p a r t u m and in some factories it is 1 year. D u r i n g the first 3 months the newborns are usually cared for by the parents. After 3 months many mothers r e t u r n to work and the infants are largely cared for by the g r a n d p a r e n t s in their homes or homes of the newborns, to a lesser extent in c o m m u n i t y nurseries and to a lesser extent
CHINESE INFANTS AND YOUNGCHILDREN still g o v e r n m e n t or factory nurseries. K i n d e r g a r t e n s or p r e s c h o o l s which are g o v e r n m e n t or factory operated, for c h i l d r e n 2 to 6 years are a v a i l a b l e but are in short supply. Less t h a n 10% of c h i l d r e n have access to these i n s t i t u t i o n s . C h i l d care in the n u r s e r y and k i n d e r g a r t e n is r e l a t i v e l y expensive. However, b e c a u s e of the "One F a m i l y One Child" policy, p a r e n t s are w i l l i n g to spend more on t h e i r one child. The a v e r a g e salary is about i00 y u a n s ( e q u i v a l e n t to about 30 U.S. dollars) per month. Rent is s u b s i d i z e d so that the cost to the family is 7 yuans per month. U t i l i t i e s cost an a d d i t i o n a l 7 y u a n s per month. F o o d u s u a l l y costs about 50% of the t o t a l family income. Cost of c h i l d care in a n u r s e r y or k i n d e r g a r t e n is about 12 y u a n s monthly, a l t h o u g h m a i n t e n a n c e of the i n s t i t u t i o n s in t e r m s of space, staff and food for the c h i l d r e n are subsidized. In some of these i n s t i t u t i o n s , p a r e n t s may be a s k e d to pay an a d d i t i o n a l 1 yuan each m o n t h for food or n u t r i e n t supplements. Parents may also supply the i n s t i t u t i o n s with food or n u t r i e n t s u p p l e m e n t s with w h i c h t h e y w i s h the i n s t i t u t i o n s to add to their c h i l d r e n ' s d i e t s p r o v i d e d by the k i n d e r g a r t e n s .
FEEDING PRACTICES By estimate, China in 1981 had enough food to p r o v i d e 2525 k i l o c a l o r i e s per capita per d a y (4). Plant foods p r o v i d e a p p r o x i m a t e l y 94% of the total d i e t a r y e n e r g y and 90% of the d i e t a r y protein. Food balance data provide i n t e r e s t i n g i n f o r m a t i o n but it is not a g o o d i n d i c a t o r of the n u t r i t i o n a l status of the p o p u l a t i o n . N e v e r t h e l e s s the d a t a s u g g e s t s that p o t e n t i a l l y China has s u f f i c i e n t food for its people. E x c e p t for breast feeding, t h e r e is little i n f o r m a t i o n on infant feeding practices; n e i t h e r is t h e r e m u c h i n f o r m a t i o n on the e a t i n g habits of y o u n g c h i l d r e n in China. Breast feeding is u n i v e r s a l in C h i n a at least d u r i n g the n e o n a t a l p e r i o d (5). In the past, the d u r a t i o n of b r e a s t feeding in urban areas was c o m m o n l y 6 m o n t h s to a year. In urban areas it was as long as 2 years. In m o r e r e c e n t years, in large cities, the d u r a t i o n of breast f e e d i n g has been on the decline. In 1980, in the city of Shanghai only a r o u n d 45% of the n e w b o r n s were e x c l u s i v e l y b r e a s t f e d , 48% were g i v e n a m i x e d feed of b r e a s t and c o w ' s m i l k and 7% were e x c l u s i v e l y b o t t l e f e d (6). By a r o u n d t h r e e and a half months only about 19% of the infants were e x c l u s i v e l y breastfed. As to be expected, as breast f e e d i n g d e c l i n e d , the i n c i d e n c e of m i x e d feeding and e x c l u s i v e b o t t l e feeding increased. In the rural areas of Shanghai, b r e a s t feeding was f o u n d to be much more p r e v a l e n t and for a longer duration.
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P e r s o n a l c o m m u n i c a t i o n with health p r o f e s s i o n a l s r e v e a l e d similar trends in other areas of China, that is, b r e a s t f e e d i n g is much more p r e v a l e n t in rural then in u r b a n areas. The r e a s o n s for these o b s e r v a t i o n s are not clear. The d e c l i n e in breast feeding in urban areas is not due to the lack of breast milk. Studies in Shanghai and South C h i n a showed that the average d a i l y breast m i l k volume of h e a l t h y m o t h e r s was a r o u n d 800 mi(7,8). S o c i o - e c o n o m i c factors are more likely the e x p l a n a t i o n . D e s p i t e the g e n e r o u s m a t e r n i t y leave more women are r e t u r n i n g to the work force e a r l i e r for e c o n o m i c reasons. Additionally, infant formulas and cow's milk are now a v a i l a b l e in the cities. The milk used in bottle feeding is p r e d o m i n a n t l y c o w ' s milk. In the city of S h a n g h a i each infant is e n t i t l e d to 200 cc of fresh cow's milk per day, and 500 g of milk p o w d e r per month (6). In other cities, the r a t i o n s of t h e s e m i l k p r o d u c t s are d i f f e r e n t and d e p e n d on t h e i r availability. Infant formulas are i m p o r t e d and are expensive. In the rural areas fresh cow's milk, milk p o w d e r and infant formulas are g e n e r a l l y not as r e a d i l y available. As a means of p r o m o t i n g longer breast feeding, some f a c t o r i e s permit time off for the m o t h e r s to b r e a s t f e e d t h e i r infants d u r i n g the day if t h e i r homes are close to the work p l a c e or if the infants are c a r e d for in the factory nursery. By and large this is not common. Breast milk e x p r e s s i o n for feeding from the b o t t l e is not p r a c t i c e d b a s i c a l l y because of the lack of r e f r i g e r a t i o n . Solid foods are u s u a l l y i n t r o d u c e d to the infants l i v i n g in urban areas by about 3 to 4 months of life (9). P l a i n rice soup is c o m m o n l y the first n o n - m i l k p r o d u c t to be introduced. As the c h i l d grows older rice c o n g e e (gruel) is u s e d and later on soft rice. Some egg yolk, w h o l e egg, meat or fish m a y be added to the congee or soft rice. In most i n s t a n c e s the amount of these p r o t e i n foods is small and is s u b s t a n t i a l l y less than that c o m m o n l y found in the d i e t s of i n f a n t s in i n d u s t r i a l i z e d countries. Seasonal fruit is o c c a s i o n a l l y given to infants. V e g e t a b l e is not c o m m o n l y found in d i e t s of infants. By about 1 year of age most infants are fed table foods. L o c a l l y p r o d u c e d baby foods are m o s t l y rice flour and b a b y c a k e s made from rice flour. T h e y are p o p u l a r t h r o u g h o u t China. T h e y are not f o r t i f i e d and are t h e r e f o r e of little n u t r i t i o n a l value. I m p o r t e d infant c e r e a l s can be found in the market p l a c e in big cities. T h e y are expensive. P r e s e n t l y the C e n t r a l A u t h o r i t i e s in C h i n a are e n c o u r a g i n g the m a n u f a c t u r e of n u t r i t i o u s b a b y foods (i0). To d a t e only the S h a n g h a i B a o B a o l e Company, w h i c h is funded by UNICEF, and the H e i n z - U F E Ltd in Guangzhou, an a f f i l i a t e of the H. J. Heinz C o m p a n y in the U.S., are p r o d u c i n g infant
CHINESE INFANTS AND YOUNG CHILDREN c e r e a l s that are fortified with protein, iron, calcium, and the B-vitamins. Both companies have limited c a p a c i t y and can only p r o d u c e sufficient amount of the foods to satisfy the r e s p e c t i v e local markets. No doubt, as time p r o g r e s s e s more factories p r o d u c i n g nutritious baby foods will be e s t a b l i s h e d in d i f f e r e n t parts of China. As t e c h n o l o g y and the e c o n o m y in China improve so will the increase in the v a r i e t y of baby foods m a n u f a c t u r e d in China. There is v i r t u a l l y no information on the eating h a b i t s of young Chinese c h i l d r e n living at home. The feeding p a t t e r n s of k i n d e r g a r t e n children 2 to 6 years of age are r e g i m e n t e d and t h e r e f o r e more is known about them. There are two types of kindergartens, live-in and day. In the live-in kindergartens, the children are fed 3 regular meals, an a f t e r n o o n and an evening snack. In the d a y kindergarten, the c h i l d r e n are p r o v i d e d an early lunch and an a f t e r n o o n snack. Breakfast and dinner are usually eaten at home. Meals at the k i n d e r g a r t e n s consist of either rice, n o o d l e s or d u m p l i n g s with meat, poultry fish or eggs and vegetables. Soup is usually served in at least one of the meals. The foods are bought fresh daily from the local m a r k e t and are c o o k e d in the k i n d e r g a r t e n kitchen. Snacks c o n s i s t of c o o k i e s or seasonal fruit. The b e v e r a g e is u s u a l l y water and at times fruit juice. The importance of milk for the p r e s c h o o l e r s is r e c o g n i z e d but it is not a v a i l a b l e to t h e m daily. There is always enough food to satisfy the children. The children feed t h e m s e l v e s but are s u p e r v i s e d by the k i n d e r g a r t e n staff.
NUTRITIONAL STATUS Judging from the information, albeit scanty, on the feeding patterns of Chinese infants and p r e s c h o o l e r s and the types and amounts of foods they eat, one can s p e c u l a t e that n u t r i t i o n a l d e f i c i e n c e s amoung t h e m do exist. However, the f o r e g o i n g must be p r e - e m p t e d by the statement that most Chinese infants and p r e s c h o o l e r s appear healthy, happy and alert. The major n u t r i t i o n a l p r o b l e m s r e p o r t e d about C h i n e s e infants and p r e s c h o o l e r s are suboptimal growth, iron deficiency, vitamin D- d e f i c i e n c y rickets and zinc deficiency. Other n u t r i t i o n a l p r o b l e m s which are b e l i e v e d to exist, but having no statistics on their prevalence, include p r o t e i n - c a l o r i e malnutrition, and d e f i c i e n c e s of calcium, vitamin A, and the B-vitamins. Iodine and s e l e n i u m d e f i c i e n c e s were p r e v a l e n t in inland and h i l l y regions, but the p r o b l e m s are under control. An e m e r g i n g p r o b l e m is infant obesity.
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MAJOR NUTRITIONAL PROBLEMS (i) Suboptimal
Growth
Breast fed infants in China grow at rates similar to those in i n d u s t r i a l i z e d c o u n t r i e s in the first 4 to 6 m o n t h s of life (8,11). Thereafter, growth s t u n t i n g in both weight and length is apparent. Similar growth s t u n t i n g has been o b s e r v e d in infants in other d e v e l o p i n g countries. Growth of infants and young c h i l d r e n are i n f l u e n c e d by e n v i r o n m e n t a l factors such as d i e t a r y intake and e p i s o d e s of diseases, and g e n e t i c make-up. International e p i d e m i o l o g i c a l studies have shown that c h i l d r e n of various ethnic g r o u p s b e l o n g i n g to e c o n o m i c a l l y a d v a n t a g e d families g r o w n e a r l y as tall and big as E u r o p e a n and North A m e r i c a n c h i l d r e n (]2). Thus, suboptimal g r o w t h o b s e r v e d in infants may be more d e p e n d e n t on d i e t a r y intake and d i s e a s e burden than on g e n e t i c make-up. Since the n u t r i t i o n a l status of an individual has a strong influence on health, d i e t a r y intake is likely the strongest d e t e r m i n a n t of growth. U n f o r t u n a t e l y , there is no data to c o r r e l a t e the a n t h r o p o m e t r i c status of Chinese infants and y o u n g c h i l d r e n and food consumption. However, the p r e l i m i n a r y r e s u l t s of a g r o w t h study in South China have p r o v i d e d some e v i d e n c e that infants p r o v i d e d n u t r i t i o u s s u p p l e m e n t s by 4 m o n t h s a c h i e v e d more rapid growth rates than infants who did not (9). (ii)
Iron D e f i c i e n c y
A large p r o p o r t i o n of y o u n g c h i l d r e n in China are not r e c e i v i n g a d e q u a t e levels of iron in their diets. A c c o r d i n g to one e s t i m a t e I00 m i l l i o n c h i l d r e n in China suffer from n u t r i t i o n a l anemia, much of which is caused by d i e t a r y iron d e f i c i e n c y (13). This estimate was based on r e s e a r c h r e p o r t e d in v a r i o u s parts of China. In a survey of 32,940 c h i l d r e n under 7 years of age c o n d u c t e d b e t w e e n 1980 and 1982 in 12 p r o v i n c e s and cities, 55.5% had a h e m o g l o b i n level less than 12 g per dl. Most of the p r o b l e m could be a t t r i b u t e d to iron deficiency. In another survey of 7,500 c h i l d r e n under 7 years of age in 8 p r o v i n c e s and cities, 40% of the c h i l d r e n were found to have a level of h e m o g l o b i n of less than ii g per dl. In H e i l o n g j i a n province, c h i l d r e n with h e m o g l o b i n less than ii g per dl and 12 g per dl a c c o u n t e d for 19.4% and 40.2% respectively. In Shanghai, the r e s p e c t i v e figures were much higher; they were 63.6% and 82.9%. In Jiangxi province, 88% of 5,167 c h i l d r e n under the age of 7 years were found to be d e f i c i e n t in iron. A study c o n d u c t e d in Chengdu showed that the incidence of anemia was higher in infants under 12 months of age than in c h i l d r e n b e t w e e n 1 and 3 years of age and in older children. A second report in Shanghai r e v e a l e d that 46.4% of the anemias d e t e c t e d in infants less than 6 m o n t h s and 100% of the
CHINESE INFANTS AND YOUNGCHILDREN anemias in infants iron deficiency.
between
6 months
and 2 years
were due to
More r e c e n t l y the Institute of Health, China N a t i o n a l Centre for P r e v e n t i v e Medicine in B e i j i n g reported that 16.5% of c h i l d r e n under 3 years of age and 35.9% of 7-12 month old infants living in urban B e i j i n g were anemic, while in the rural areas the c o r r e s p o n d i n g figures were 35.1% and 48.8% respectively(14). The mean iron intake of t h e s e c h i l d r e n was 8.3 mg per day. The low h e m o g l o b i n level of these children r e s p o n d e d to a supplement of iron in the form of an iron and v i t a m i n C - f o r t i f i e d soft-drink. The e t i o l o g y of iron d e f i c i e n c y anemia is not clear. Dietary iron d e f i c i e n c y is the most probable cause. Studies on infant feeding c o n d u c t e d in South China (9) showed that the foods in w e a n i n g diets were g e n e r a l l y of poor n u t r i t i o n a l quality. Iron-rich foods seldom a p p e a r e d in the d i e t a r y records and if they did, the amounts c o n s u m e d were low. Low b i o a v a i l a b i l i t y of the food iron could be a n o t h e r reason. The impression of many c l i n i c i a n s in China is that the iron content in the diets of some infants is adequate, however, the iron is not assimilated. These i m p r e s s i o n s are based on the high c a r b o h y d r a t e content in t r a d i t i o n a l w e a n i n g foods which likely contain high levels of s u b s t a n c e s that interfere with iron absorption, and the a p p a r e n t lack of non-heme inorganic iron a b s o r p t i o n p r o m o t e r s such as meat, fish and ascorbic acid. (iii)
Vitamin
D Deficiency
Vitamin D - d e f i c i e n c y rickets is r e p o r t e d l y high among infants and young children. R i c k e t s has been d o c u m e n t e d in as many as 18% of infants in parts of China (15,16). In 1979, a survey of i0 p r o v i n c e s of over 70,000 c h i l d r e n 3 years and younger found the p r e v a l e n c e of rickets to be 29%. The highest incidence was among infants 6 to 24 months of age. In Beijing, the clincial impression is that as many as 40% of young c h i l d r e n suffer vitamin D - d e f i c i e n c y (personal c o m m u n i c a t i o n - B e i j i n g Children's Hospital). In Guangzhou, in South China, 16% of infants may have vitamin D - d e f i c i e n c y rickets (personal c o m m u n i c a t i o n - D e p a r t m e n t of Pediatrics, Sun Yat Sen U n i v e r s i t y of Medical Sciences). There is a regional d i f f e r e n c e in the p r e v a l e n c e rate, it is higher in northern or m o u n t a i n o u s regions where r i c k e t s is a s s o c i a t e d with long winter months and the lack of sunshine and vitamin D-rich foods. In the south, the c o n s i d e r e d opinion is p r i m a r i l y o v e r - p r o t e c t i o n (over d r e s s i n g in the winter and sheltering from the hot sun in the summer) of the one child.
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D.L. YEUNG (iv) Zinc D e f i c i e n c y
Zinc d e f i c i e n c y is also a p r o b l e m a m o n g y o u n g c h i l d r e n in parts of China where the zinc c o n t e n t in the soil is low. In Beijing, the c a l c u l a t e d d i e t a r y zinc intake of k i n d e r g a r t e n c h i l d r e n r a n g e d from 4.5 to 5.5 mg daily, w h i c h is only 50% of the U.S. R e c o m m e n d e d Daily A l l o w a n c e (17). A d d i t i o n a l l y , 23% of the children, b e t w e e n 1 and 6 years, who were brought to a Child H e a l t h C l i n i c and 34% of c h i l d r e n s a m p l e d in n u r s e r i e s and k i n d e r g a r t e n had low hair zinc levels and were c o n s i d e r e d at risk of zinc d e f i c i e n c y , a l t h o u g h m e a s u r e m e n t of the level of zinc in the hair is g e n e r a l l y c o n s i d e r e d to be u n r e l i a b l e for the a s s e s s e m e n t of zinc status. N e v e r t h e l e s s , these c h i l d r e n were r e s p o n s i v e to zinc s u p p l e m e n t a t i o n as shown by d i s a p p e a r a n c e of pica and a n o r e x i a and i n c r e a s e d growth.
OTHER NUTRITIONAL PROBLEMS The f o l l o w i n g n u t r i t i o n a l p r o b l e m s are believed, i n f o r m e d sources in China, to exist but no s t a t i s t i c s their p r e v a l e n c e have been reported. (i)
Protein-Calorie
by on
Malutrition
A c c o r d i n g to the i m p r e s s i o n of n u t r i t i o n i s t s in China, p r o t e i n - c a l o r i e m a l n u t r i t i o n e x i s t s but the p r o b l e m is rare. Few cases of p r o t e i n - c a l o r i e m a l n u t r i t i o n are t r e a t e d a n n u a l l y in C h i l d r e n ' s H o s p i t a l s in d i f f e r e n t parts of China. Cases r e p o r t e d are m o s t l y in rural and r e m o t e areas of the country. (ii) C a l c i u m
Deficiency
C a l c i u m d e f i c i e n c y is s u s p e c t e d to be w i d e s p r e a d . A c c o r d i n g to n u t r i t i o n i s t s in China, the c a l c i u m c o n t e n t in d i e t s of infants and young c h i l d r e n is less than 50% of the C h i n e s e R e c o m m e n d e d Daily A l l o w a n c e s of 600 mg of c a l c i u m for c h i l d r e n less than 3 years of age (18). The p r o b l e m a p p e a r s to be r e l a t e d to the low levels of d a i r y p r o d u c t s in the d i e t s of the children. The c o n d i t i o n is a l s o t h o u g h t to be a s s o c i a t e d with the low vitamin D intake w h i c h may h i n d e r o p t i m a l u t i l i z a t i o n of the d i e t a r y calcium. (iii)
Vitamin
A Deficiency
V i t a m i n A - d e f i c i e n c y x e r o p t h a l m i a and b l i n d n e s s a f f e c t a large number of young c h i l d r e n in some South East A s i a n c o u n t r i e s (19). This p r o b l e m o f t e n a c c o m p a n i e s protein-calorie malnutrition. In most of these countries, v i t a m i n A -rich foods such as y e l l o w and green leafy v e g e t a b l e s , are p l e n t i f u l but because of poverty, c u l t u r a l t a b o o s and i g n o r a n c e they are not i n c l u d e d in the d i e t s of i n f a n t s and y o u n g children.
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A c c o r d i n g to the World Bank, vitamin A d e f i c i e n c y is not a major p r o b l e m in China (3). However, C h i n e s e n u t r i t i o n i s t s believe that vitamin A d e f i c i e n c y does exist but m a i n l y in remote areas of China where v i t a m i n A- rich foods are scarce. (iv)
Deficiency
of the B-vitamins
The extent of vitamin B d e f i c i e n c y in China is not known. Beri-Beri and a r i b o f l a v i n o s i s were common p r o b l e m s prior to 1949 (20). T h i a m i n d e f i c i e n c y had become less of a p r o b l e m since the e l i m i n a t i o n of the use of p o l i s h e d rice. However, in recent years, b e c a u s e of the i m p r o v e d economy, p o l i s h e d rice is again b e c o m i n g popular. W h e t h e r or not Beri-Beri will r e s u r g e as a n u t r i t i o n a l p r o b l e m among infants and young c h i l d r e n r e m a i n s to be determined. Ariboflavinosis, at least marginal r i b o f l a v i n deficiency, is supected to be a p r o b l e m but the extent of the p r o b l e m is unknown. The suspicion is based on the low levels of d a i r y p r o d u c t s and meats in the d i e t s of infants and preschoolers. Among adolescents 12 to 19 years of age, r i b o f l a v i n d e f i c i e n c y has been found to be prevalent. In a study of 11,200 school children aged 12 to 19 y e a r s in the p r o v i n c e of G u a n g d o n g the mean daily r i b o f l a v i n intake was 0.45 mg, which is only 32% of the r e c o m m e n d e d d a i l y a l l o w a n c e for this age group (21). The main sources of r i b o f l a v i n were: rice (50%), vegetables (30%), soya bean p r o d u c t s (13%) and fish and meat (7%). The o b s e r v e d clinical signs of riboflavin d e f i c i e n c y were: scrotal d e r m a t i t i s (7.9% of boys), a n g u l a r s t o m a t i t i s (5.8% of boys, 2.7% of girls), c h e i l o s i s (8.0% of boys, 5.6% of girls), and m a g e n t a tongue (36.0% of boys, 40.8% of girls). Scrotal lesions were r e s o l v e d within 3 to 6 days after oral a d m i n i s t r a t i o n of 15 mg of r i b o f l a v i n per day. The r e s o l u t i o n of d e f i c i e n c y signs on the t o n g u e and lips p r o g r e s s e d more slowly.
NUTRITIONAL PROBLEMSTHAT ARE SUCCESSFULLYCONTROLLED In spite of the vastness of the country and the many n u t r i t i o n a l problems that exist it is worthy of note that China has s u c c e s s f u l l y c o n t r o l l e d two p r e v a l e n t and d e b i l i t a t i n g n u t r i t i o n a l diseases: Keshan D i s e a s e and E n d e m i c Goitre. (i)
Selenium
Selenium has been p r e v a l e n t
Deficiency deficiency, also known as Keshan in China for more than a h u n d r e d
Disease, years
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D.L. YEUNG
(22,23). The d i s e a s e is found m a i n l y between the coastal zone of North Eastern China and the island zone of South W e s t e r n China in hilly lands but not in high m o u n t a i n s or plains. Keshan d i s e a s e affects 1% of children under i0 years of age and 95% of the cases occur in c h i l d r e n between 2 and 7 years of age (3). Over the years the incidence has d r a s t i c a l l y decreased. Between 1978 and 1980 less than 1 death per i00,000 p o p u l a t i o n was recorded. The r e m a r k a b l e d e c l i n e of the s e l e n i u m d e f i c i e n c y is due to a l t e r a t i o n of the diet to include high selenium foods, such as maize and soybeans or sodium selenite supplements (24). (ii)
Iodin e D e f i c i e n c y
A p p r o x i m a t e l y 300 million people live in known iodine d e f i c i e n t areas located in inland and m o u n t a i n o u s regions of China. In 1978, 34 million people were c o n s i d e r e d g o i t r o u s and 200,000 people were cretins (25,26,27). Since then, through iodination of salt and oil, i0 m i l l i o n individuals are said to be cured and 130 m i l l i o n are being p r o t e c t e d . The success in c o n t r o l l i n g iodine d e f i c i e n c y can be a t t r i b u t e d to several factors such as (a) the forceful and p r a g m a t i c action taken and (b) the tight g o v e r n m e n t control on salt movement and trade.
AN EMERGING PROBLEM-INFANT OBESITY The above d e s c r i b e d some of the n u t r i t i o n a l p r o b l e m s that exist among Chinese infants and young children. All the p r o b l e m s are due to nutrient deficiencies. An e m e r g i n g p r o b l e m that is of concern to health p r o f e s s i o n a l s is infant obesity. Because of the "One F a m i l y One Child" p o l i c y , C h i n e s e p a r e n t s dote on their c h i l d r e n . As i n d i c a t e d earlier, parents are w i l l i n g to spend more of their hard earned money to satisfy the wants of their infants. B e c a u s e of the lack of n u t r i t i o n knowledge, a fat baby is p e r c e i v e d to be a healthy baby. There is now a t e n d e n c y to o v e r f e e d infants with p e r c e i v e d and real n u t r i t i o u s foods and c o n f e c t i o n a r i e s that young children enjoy. This s i t u a t i o n d e s e r v e s m o n i t o r i n g e s p e c i a l l y if the foods are low in n u t r i e n t density.
SUMMARY China recognizes the importance of n u t r i t i o n to the health of her people (28). Infant n u t r i t i o n and the m a n u f a c t u r e of n u t r i t i o u s baby food are p r i o r i t i e s in p u b l i c health policies. Today, China is m a k i n g great strides in the m o d e r n i z a t i o n of agriculture, i n d u s t r y and science and technology. Potentially, there is enough food for all. The p o l i t i c a l system can control e q u i t a b l e d i s t r i b u t i o n of China's commodities (29). However, China can meet the n u t r i t i o n a l needs of her future g e n e r a t i o n s
CHINESE INFANTS AND YOUNGCHILDREN only if the nutritional needs of the population understood and appropriate measures are taken.
are clearly
The child health and welfare system in China is commendable. For a country having an annual birth rate of close to 20 million, the low infant mortality rate is remarkable (3). Every child is housed, clothed, fed and educated. By and large, Chinese infants and children are healthy. However their nutritional well being can be improved. Growth stunting, iron-deficiency anemia, vitamin D-deficiency rickets and zinc deficiency are prevalent. Vitamin A deficiency, calcium deficiency and deficiency of the B-vitamins exist, but the statistics on the extent of these nutritional problems are badly lacking. To improve the nutrition of infants and young children in China, a greater knowledge of their feeding and eating habits, and the prevalence and the etiology of the nutritional problems is needed. China has demonstrated that it can, in a relatively short time, eliminate serious and widespread nutritional problems. The case in point is the rapid resolution of Keshan Disease and Endemic Goitre. Having a good knowledge of the extent of the problem, China can implement forceful and pragmatic programs to fruitful solutions. Notwithstanding, the backing of the authorities is key. The measure of success of the birth control policy and the modernization programs in China is not the size of the population nor the technology that is gained, but the health and-well being of the future generations.
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i0 percent sampling tabulation on the 1982 population cenus~of the Peoples Republic of China. Ed. by Population Census Office under the State Council and Department of Population Statistics, State Statistics Bureau, People's Republic of China. 1983.
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Jamison, D.T., Evans, J.R., King. T., Porter, L., Prescott, H., Post, A. China. The health sector. A World Bank Country Study. The World Bank, Washington, D.C., U.S.A. 1984.
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Young, M.E., Post, A. Child health in China. The World Bank Staff Working Papers, no. 607. The World Bank, Washington, D.C., U.S.A. 1985.
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Piazza, A. Trends in food and nutrient availability in China, 1950-81. The World Bank Staff Working Papers, no. 167. The World Bank, Washington, D.C., U.S.A. 1983.
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Arena, J. China's children. 1985;20-25.
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WHO collaborative study and investigation of breastfeeding in Shanghai. Shanghai, People's Republic of China. 1982.
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Su, T.F. An investigation of breast milk volumes at 1-4 months after delivery. Shanghai Children's Hospital, Shanghai, People's Republic of China (unpublished report). 1982.
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Ho, Z.C. Breastfeeding in Xinhui District in China. Food Nutr. Buli.1981;3:42-48.
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Ho, Z.C., Wu, W.Y., Yeung, D.L. Infant feeding and growth in a rural district in South China. 13th International Congress of Nutrition, Brighton, England.1985; Abstract no. C21.
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Newman, J. M., Contento, I., Kris, E. Perspectives on food and nutrition in the People's Republic of China. J. Nutr. Ed.1981;13: 43-45.
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Jamison, D.T., Trowbridge, F.L. The nutritional status of children in china: A Review of the anthropometric evidence. Population, Health and Nutrition Department, Centers for Disease Control, Atlanta, Georgia, U.S.A. PHN Technical Notes, Genl7. 1983.
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Habicht, J.P., Matorell, R., Yarbrough, C., Medina, R.M., Klein, R.L. Height and weight standard for preschool children. How relevant are ethnic differences in growth potential? Lancet 1974;1:61]-615.
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Zheng, Z.N. Present status of nutritional anemia in China. Report of the 9th Meeting of the International Anemia Consultative Group. WHO Headquarters, Geneva, Switzerland. 1985.
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Wong, W., Chen, X.C., Lui, D.S. Hematologic response to iron and ascorbic acid administration in pre-school children with anemia. Nutr. Res.1986;6:241-248.
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Fong, H.C., Huong, H.M., Shen, K.U., Dewen, P.L. Prevention and treatment of rickets (report). Henan, People's Republic of China. Henan College of Medicine Publication (Chinese) 1980;1-10.
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Xiao, L. Survey of infant rickets. J. Chinese Pediatr. (Chinese).]982;2:20.
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Chen, X.C., He, J.S., Ma, Q.Y., Han, Z.M., Li, L.X. Low levels of zinc in liver and blood, pica, anorexia and poor growth in Chinese pre-school children. Amer. J. Clin. Nutr.1985;62: 694-700.
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Food composition tables. Beijing: The Institute of Health, Chinese Academy of Medical Sciences of Beijing. 1981.
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Vitamin A-deficiency and xeropthalmia. World Health Organization, Technical Report Series no.672, Geneva, Switzerland. 1982.
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Chen, X.C., Ge, K. Y., Liu, L.F. Studies prevention of beri-beri. J. Appl. Nutr. (Chinese).1984;6:135-139.
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Lo, C.S. Riboflavin studies of adolescents in Southern China. Average intake of riboflavin and clinical findings. Med. J. Australia 1984;141:635-637.
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Selenium
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Keshan Disease Research Group, Chinese Academy of Medical Sciences. Studies on the epidemiological characteristics on the etiological relationship of selenium to Keshan Disease. Nat. Med. J. China (Chinese).1979;59:451-456.
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Research Laboratory of Keshan Disease Group, Xian Medical College. Observation on the effects of sodium selenite for preventing acute Keshan Disease. Nat. Med. J. China (Chinese).1979;59: 457-462.
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Zhu, X.Y. Development of ongoing research work on endemic goiter and cretenism. Nat. Med. J. China (Chinese).1980;60: 705-707.
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Zhang, C.Q., Ni, G.Z., Zhao, Y.D. Growth and physiological analysis of pupils in the endemic goiter area. Chinese J. Prev. Med. (Chinese).1983; 17: 93-97.
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Kochupillai, N., Pandav, C.S. Iodine deficiency disorders in China. Current status, control measures and future strategies. Consultant's Report, UNICEF/ROSCA, New Delhi. 1985.
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Yu, R.M. Nutrition - An important matter involving people's health. Beijing, Red Flag no. 17, 1983; 3033,39, Sept. i.
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Rada,
in the heart
E.L.
Food policy
of China.
in China.
518-535. Accepted for publication September 15, 1987
Lancet
Asian
on the
1973;27:889-90.
Survey
1983;23:
Nutrition of Infants and Young Children in China David L. Yeung, Ph.D. Head, Heinz Institute of Nutritional Sciences Shahe, Yang Tang, Guangzhou People's Republic of China
ABSTRACT
A p p r o x i m a t e l y 20 million infants are born in China annually. During the neonatal period most of the infants are b r e a s t f e d and they grow at rates similar to infants raised in i n d u s t r i a l i z e d countries. Past three months of age, p a r t i c u l a r l y in urban areas, many infants are w e a n e d from the breast and are given foods of low n u t r i t i o n a l value. C o n s e q u e n t l y suboptimal growth, and iron d e f i c i e n c y are prevalent. Vitamin D - d e f i c i e n c y rickets and zinc d e f i c i e n c y are also evident. Other n u t r i t i o n a l p r o b l e m s such as p r o t e i n - c a l o r i e malnutrition, d e f i c i e n c e s of vitamin A, calcium, and the B-vitamins have been r e p o r t e d but no statistics on the p r e v a l e n c e of these problems are available. Infant o b e s i t y is an e m e r g i n g problem. S e l e n i u m and iodine d e f i c i e n c i e s have been controlled. Child health and welfare are e m p h a s i z e d in public health services in China, but the k n o w l e d g e of infant feeding p r a c t i c e s needs to be improved. Key words:
Breastfeeding, feeding practices, nutritional deficiences, infants, preschoolers
growth,
INTRODUCTION China is g e o g r a p h i c a l l y the third largest country in the world. It o c c u p i e s 9.6 million square k i l o m e t e r s or one fourteenth of the total land area of the world. It has the largest population, close to one billion, which is more than o n e - f i f t h of the world p o p u l a t i o n (i). Eighty percent of the p o p u l a t i o n live in rural areas and 20% urban areas. C o r r e s p o n d i n g address: H.J. 5650 Yonge St., North York,
Heinz Company of Canada Ontario, M2M 4G3
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Ltd.,
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In 1949 when the present government took control, the p o p u l a t i o n in China was about 400 million. By 1980 it had r e a c h e d one billion. This rapid growth was the result of (a) high birth rate, (b) d e c r e a s e d infant m o r t a l i t y and (c) increase in life span from 32 years in 1949 to 69 years in 1982 (2). The latter remarkable achievement could be a t t r i b u t e d to the more equitable d i s t r i b u t i o n of daily n e c e s s i t i e s and improved public health p r e v e n t i v e services. In 1979, the central authorities in China a n n o u n c e d the "One Family One Child" policy (2). The aim was to c u r b the rapid p o p u l a t i o n growth, to improve the national economy, to raise the standard of living and to achieve the four m o d e r n i z a t i o n p r o g r a m s in agriculture, industry, defense and science and technology. In spite of the stringent birth control policy, the annual birth rate in China today is close to 20 million. The purpose of this paper is to p r e s e n t an o v e r v i e w on child care, infant feeding p r a c t i c e s and p r e v a l e n t n u t r i t i o n a l problems in infants in China today. The i n f o r m a t i o n p r e s e n t e d is based on a v a i l a b l e literature, clinical impressions of health p r o f e s s i o n a l s in China and o b s e r v a t i o n s made by the author during his frequent visits to China.
CHILD CARE In China, women are e n c o u r a g e d not to become p r e g n a n t until 3 to 5 years after marriage and not before 24 years of age. Even then, a woman may become p r e g n a n t only by p e r m i s s i o n based on a quota system, from the p o p u l a t i o n control committee in the community to which the woman belongs. Once p e r m i s s i o n is granted and p r e g n a n c y is established, the mother receives c o m p r e h e n s i v e a n t e n a t a l care (3). The p a r e n t s attend prenatal classes where child care, n u t r i t i o n and other pertinent subjects are taught. Postnatally, child health services include home visits for care of newborns and routine physical e x a m i n a t i o n s in local Maternal and Child Health Centers. Preventive services in growth m o n i t o r i n g and i m m u n i z a t i o n are also p r o v i d e d in these centers. M a t e r n i t y leave is generous. M a t e r n i t y leave with pay is n o r m a l l y 56 days p o s t p a r t u m and in some factories it is 1 year. D u r i n g the first 3 months the newborns are usually cared for by the parents. After 3 months many mothers r e t u r n to work and the infants are largely cared for by the g r a n d p a r e n t s in their homes or homes of the newborns, to a lesser extent in c o m m u n i t y nurseries and to a lesser extent
CHINESE INFANTS AND YOUNGCHILDREN still g o v e r n m e n t or factory nurseries. K i n d e r g a r t e n s or p r e s c h o o l s which are g o v e r n m e n t or factory operated, for c h i l d r e n 2 to 6 years are a v a i l a b l e but are in short supply. Less t h a n 10% of c h i l d r e n have access to these i n s t i t u t i o n s . C h i l d care in the n u r s e r y and k i n d e r g a r t e n is r e l a t i v e l y expensive. However, b e c a u s e of the "One F a m i l y One Child" policy, p a r e n t s are w i l l i n g to spend more on t h e i r one child. The a v e r a g e salary is about i00 y u a n s ( e q u i v a l e n t to about 30 U.S. dollars) per month. Rent is s u b s i d i z e d so that the cost to the family is 7 yuans per month. U t i l i t i e s cost an a d d i t i o n a l 7 y u a n s per month. F o o d u s u a l l y costs about 50% of the t o t a l family income. Cost of c h i l d care in a n u r s e r y or k i n d e r g a r t e n is about 12 y u a n s monthly, a l t h o u g h m a i n t e n a n c e of the i n s t i t u t i o n s in t e r m s of space, staff and food for the c h i l d r e n are subsidized. In some of these i n s t i t u t i o n s , p a r e n t s may be a s k e d to pay an a d d i t i o n a l 1 yuan each m o n t h for food or n u t r i e n t supplements. Parents may also supply the i n s t i t u t i o n s with food or n u t r i e n t s u p p l e m e n t s with w h i c h t h e y w i s h the i n s t i t u t i o n s to add to their c h i l d r e n ' s d i e t s p r o v i d e d by the k i n d e r g a r t e n s .
FEEDING PRACTICES By estimate, China in 1981 had enough food to p r o v i d e 2525 k i l o c a l o r i e s per capita per d a y (4). Plant foods p r o v i d e a p p r o x i m a t e l y 94% of the total d i e t a r y e n e r g y and 90% of the d i e t a r y protein. Food balance data provide i n t e r e s t i n g i n f o r m a t i o n but it is not a g o o d i n d i c a t o r of the n u t r i t i o n a l status of the p o p u l a t i o n . N e v e r t h e l e s s the d a t a s u g g e s t s that p o t e n t i a l l y China has s u f f i c i e n t food for its people. E x c e p t for breast feeding, t h e r e is little i n f o r m a t i o n on infant feeding practices; n e i t h e r is t h e r e m u c h i n f o r m a t i o n on the e a t i n g habits of y o u n g c h i l d r e n in China. Breast feeding is u n i v e r s a l in C h i n a at least d u r i n g the n e o n a t a l p e r i o d (5). In the past, the d u r a t i o n of b r e a s t feeding in urban areas was c o m m o n l y 6 m o n t h s to a year. In urban areas it was as long as 2 years. In m o r e r e c e n t years, in large cities, the d u r a t i o n of breast f e e d i n g has been on the decline. In 1980, in the city of Shanghai only a r o u n d 45% of the n e w b o r n s were e x c l u s i v e l y b r e a s t f e d , 48% were g i v e n a m i x e d feed of b r e a s t and c o w ' s m i l k and 7% were e x c l u s i v e l y b o t t l e f e d (6). By a r o u n d t h r e e and a half months only about 19% of the infants were e x c l u s i v e l y breastfed. As to be expected, as breast f e e d i n g d e c l i n e d , the i n c i d e n c e of m i x e d feeding and e x c l u s i v e b o t t l e feeding increased. In the rural areas of Shanghai, b r e a s t feeding was f o u n d to be much more p r e v a l e n t and for a longer duration.
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P e r s o n a l c o m m u n i c a t i o n with health p r o f e s s i o n a l s r e v e a l e d similar trends in other areas of China, that is, b r e a s t f e e d i n g is much more p r e v a l e n t in rural then in u r b a n areas. The r e a s o n s for these o b s e r v a t i o n s are not clear. The d e c l i n e in breast feeding in urban areas is not due to the lack of breast milk. Studies in Shanghai and South C h i n a showed that the average d a i l y breast m i l k volume of h e a l t h y m o t h e r s was a r o u n d 800 mi(7,8). S o c i o - e c o n o m i c factors are more likely the e x p l a n a t i o n . D e s p i t e the g e n e r o u s m a t e r n i t y leave more women are r e t u r n i n g to the work force e a r l i e r for e c o n o m i c reasons. Additionally, infant formulas and cow's milk are now a v a i l a b l e in the cities. The milk used in bottle feeding is p r e d o m i n a n t l y c o w ' s milk. In the city of S h a n g h a i each infant is e n t i t l e d to 200 cc of fresh cow's milk per day, and 500 g of milk p o w d e r per month (6). In other cities, the r a t i o n s of t h e s e m i l k p r o d u c t s are d i f f e r e n t and d e p e n d on t h e i r availability. Infant formulas are i m p o r t e d and are expensive. In the rural areas fresh cow's milk, milk p o w d e r and infant formulas are g e n e r a l l y not as r e a d i l y available. As a means of p r o m o t i n g longer breast feeding, some f a c t o r i e s permit time off for the m o t h e r s to b r e a s t f e e d t h e i r infants d u r i n g the day if t h e i r homes are close to the work p l a c e or if the infants are c a r e d for in the factory nursery. By and large this is not common. Breast milk e x p r e s s i o n for feeding from the b o t t l e is not p r a c t i c e d b a s i c a l l y because of the lack of r e f r i g e r a t i o n . Solid foods are u s u a l l y i n t r o d u c e d to the infants l i v i n g in urban areas by about 3 to 4 months of life (9). P l a i n rice soup is c o m m o n l y the first n o n - m i l k p r o d u c t to be introduced. As the c h i l d grows older rice c o n g e e (gruel) is u s e d and later on soft rice. Some egg yolk, w h o l e egg, meat or fish m a y be added to the congee or soft rice. In most i n s t a n c e s the amount of these p r o t e i n foods is small and is s u b s t a n t i a l l y less than that c o m m o n l y found in the d i e t s of i n f a n t s in i n d u s t r i a l i z e d countries. Seasonal fruit is o c c a s i o n a l l y given to infants. V e g e t a b l e is not c o m m o n l y found in d i e t s of infants. By about 1 year of age most infants are fed table foods. L o c a l l y p r o d u c e d baby foods are m o s t l y rice flour and b a b y c a k e s made from rice flour. T h e y are p o p u l a r t h r o u g h o u t China. T h e y are not f o r t i f i e d and are t h e r e f o r e of little n u t r i t i o n a l value. I m p o r t e d infant c e r e a l s can be found in the market p l a c e in big cities. T h e y are expensive. P r e s e n t l y the C e n t r a l A u t h o r i t i e s in C h i n a are e n c o u r a g i n g the m a n u f a c t u r e of n u t r i t i o u s b a b y foods (i0). To d a t e only the S h a n g h a i B a o B a o l e Company, w h i c h is funded by UNICEF, and the H e i n z - U F E Ltd in Guangzhou, an a f f i l i a t e of the H. J. Heinz C o m p a n y in the U.S., are p r o d u c i n g infant
CHINESE INFANTS AND YOUNG CHILDREN c e r e a l s that are fortified with protein, iron, calcium, and the B-vitamins. Both companies have limited c a p a c i t y and can only p r o d u c e sufficient amount of the foods to satisfy the r e s p e c t i v e local markets. No doubt, as time p r o g r e s s e s more factories p r o d u c i n g nutritious baby foods will be e s t a b l i s h e d in d i f f e r e n t parts of China. As t e c h n o l o g y and the e c o n o m y in China improve so will the increase in the v a r i e t y of baby foods m a n u f a c t u r e d in China. There is v i r t u a l l y no information on the eating h a b i t s of young Chinese c h i l d r e n living at home. The feeding p a t t e r n s of k i n d e r g a r t e n children 2 to 6 years of age are r e g i m e n t e d and t h e r e f o r e more is known about them. There are two types of kindergartens, live-in and day. In the live-in kindergartens, the children are fed 3 regular meals, an a f t e r n o o n and an evening snack. In the d a y kindergarten, the c h i l d r e n are p r o v i d e d an early lunch and an a f t e r n o o n snack. Breakfast and dinner are usually eaten at home. Meals at the k i n d e r g a r t e n s consist of either rice, n o o d l e s or d u m p l i n g s with meat, poultry fish or eggs and vegetables. Soup is usually served in at least one of the meals. The foods are bought fresh daily from the local m a r k e t and are c o o k e d in the k i n d e r g a r t e n kitchen. Snacks c o n s i s t of c o o k i e s or seasonal fruit. The b e v e r a g e is u s u a l l y water and at times fruit juice. The importance of milk for the p r e s c h o o l e r s is r e c o g n i z e d but it is not a v a i l a b l e to t h e m daily. There is always enough food to satisfy the children. The children feed t h e m s e l v e s but are s u p e r v i s e d by the k i n d e r g a r t e n staff.
NUTRITIONAL STATUS Judging from the information, albeit scanty, on the feeding patterns of Chinese infants and p r e s c h o o l e r s and the types and amounts of foods they eat, one can s p e c u l a t e that n u t r i t i o n a l d e f i c i e n c e s amoung t h e m do exist. However, the f o r e g o i n g must be p r e - e m p t e d by the statement that most Chinese infants and p r e s c h o o l e r s appear healthy, happy and alert. The major n u t r i t i o n a l p r o b l e m s r e p o r t e d about C h i n e s e infants and p r e s c h o o l e r s are suboptimal growth, iron deficiency, vitamin D- d e f i c i e n c y rickets and zinc deficiency. Other n u t r i t i o n a l p r o b l e m s which are b e l i e v e d to exist, but having no statistics on their prevalence, include p r o t e i n - c a l o r i e malnutrition, and d e f i c i e n c e s of calcium, vitamin A, and the B-vitamins. Iodine and s e l e n i u m d e f i c i e n c e s were p r e v a l e n t in inland and h i l l y regions, but the p r o b l e m s are under control. An e m e r g i n g p r o b l e m is infant obesity.
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MAJOR NUTRITIONAL PROBLEMS (i) Suboptimal
Growth
Breast fed infants in China grow at rates similar to those in i n d u s t r i a l i z e d c o u n t r i e s in the first 4 to 6 m o n t h s of life (8,11). Thereafter, growth s t u n t i n g in both weight and length is apparent. Similar growth s t u n t i n g has been o b s e r v e d in infants in other d e v e l o p i n g countries. Growth of infants and young c h i l d r e n are i n f l u e n c e d by e n v i r o n m e n t a l factors such as d i e t a r y intake and e p i s o d e s of diseases, and g e n e t i c make-up. International e p i d e m i o l o g i c a l studies have shown that c h i l d r e n of various ethnic g r o u p s b e l o n g i n g to e c o n o m i c a l l y a d v a n t a g e d families g r o w n e a r l y as tall and big as E u r o p e a n and North A m e r i c a n c h i l d r e n (]2). Thus, suboptimal g r o w t h o b s e r v e d in infants may be more d e p e n d e n t on d i e t a r y intake and d i s e a s e burden than on g e n e t i c make-up. Since the n u t r i t i o n a l status of an individual has a strong influence on health, d i e t a r y intake is likely the strongest d e t e r m i n a n t of growth. U n f o r t u n a t e l y , there is no data to c o r r e l a t e the a n t h r o p o m e t r i c status of Chinese infants and y o u n g c h i l d r e n and food consumption. However, the p r e l i m i n a r y r e s u l t s of a g r o w t h study in South China have p r o v i d e d some e v i d e n c e that infants p r o v i d e d n u t r i t i o u s s u p p l e m e n t s by 4 m o n t h s a c h i e v e d more rapid growth rates than infants who did not (9). (ii)
Iron D e f i c i e n c y
A large p r o p o r t i o n of y o u n g c h i l d r e n in China are not r e c e i v i n g a d e q u a t e levels of iron in their diets. A c c o r d i n g to one e s t i m a t e I00 m i l l i o n c h i l d r e n in China suffer from n u t r i t i o n a l anemia, much of which is caused by d i e t a r y iron d e f i c i e n c y (13). This estimate was based on r e s e a r c h r e p o r t e d in v a r i o u s parts of China. In a survey of 32,940 c h i l d r e n under 7 years of age c o n d u c t e d b e t w e e n 1980 and 1982 in 12 p r o v i n c e s and cities, 55.5% had a h e m o g l o b i n level less than 12 g per dl. Most of the p r o b l e m could be a t t r i b u t e d to iron deficiency. In another survey of 7,500 c h i l d r e n under 7 years of age in 8 p r o v i n c e s and cities, 40% of the c h i l d r e n were found to have a level of h e m o g l o b i n of less than ii g per dl. In H e i l o n g j i a n province, c h i l d r e n with h e m o g l o b i n less than ii g per dl and 12 g per dl a c c o u n t e d for 19.4% and 40.2% respectively. In Shanghai, the r e s p e c t i v e figures were much higher; they were 63.6% and 82.9%. In Jiangxi province, 88% of 5,167 c h i l d r e n under the age of 7 years were found to be d e f i c i e n t in iron. A study c o n d u c t e d in Chengdu showed that the incidence of anemia was higher in infants under 12 months of age than in c h i l d r e n b e t w e e n 1 and 3 years of age and in older children. A second report in Shanghai r e v e a l e d that 46.4% of the anemias d e t e c t e d in infants less than 6 m o n t h s and 100% of the
CHINESE INFANTS AND YOUNGCHILDREN anemias in infants iron deficiency.
between
6 months
and 2 years
were due to
More r e c e n t l y the Institute of Health, China N a t i o n a l Centre for P r e v e n t i v e Medicine in B e i j i n g reported that 16.5% of c h i l d r e n under 3 years of age and 35.9% of 7-12 month old infants living in urban B e i j i n g were anemic, while in the rural areas the c o r r e s p o n d i n g figures were 35.1% and 48.8% respectively(14). The mean iron intake of t h e s e c h i l d r e n was 8.3 mg per day. The low h e m o g l o b i n level of these children r e s p o n d e d to a supplement of iron in the form of an iron and v i t a m i n C - f o r t i f i e d soft-drink. The e t i o l o g y of iron d e f i c i e n c y anemia is not clear. Dietary iron d e f i c i e n c y is the most probable cause. Studies on infant feeding c o n d u c t e d in South China (9) showed that the foods in w e a n i n g diets were g e n e r a l l y of poor n u t r i t i o n a l quality. Iron-rich foods seldom a p p e a r e d in the d i e t a r y records and if they did, the amounts c o n s u m e d were low. Low b i o a v a i l a b i l i t y of the food iron could be a n o t h e r reason. The impression of many c l i n i c i a n s in China is that the iron content in the diets of some infants is adequate, however, the iron is not assimilated. These i m p r e s s i o n s are based on the high c a r b o h y d r a t e content in t r a d i t i o n a l w e a n i n g foods which likely contain high levels of s u b s t a n c e s that interfere with iron absorption, and the a p p a r e n t lack of non-heme inorganic iron a b s o r p t i o n p r o m o t e r s such as meat, fish and ascorbic acid. (iii)
Vitamin
D Deficiency
Vitamin D - d e f i c i e n c y rickets is r e p o r t e d l y high among infants and young children. R i c k e t s has been d o c u m e n t e d in as many as 18% of infants in parts of China (15,16). In 1979, a survey of i0 p r o v i n c e s of over 70,000 c h i l d r e n 3 years and younger found the p r e v a l e n c e of rickets to be 29%. The highest incidence was among infants 6 to 24 months of age. In Beijing, the clincial impression is that as many as 40% of young c h i l d r e n suffer vitamin D - d e f i c i e n c y (personal c o m m u n i c a t i o n - B e i j i n g Children's Hospital). In Guangzhou, in South China, 16% of infants may have vitamin D - d e f i c i e n c y rickets (personal c o m m u n i c a t i o n - D e p a r t m e n t of Pediatrics, Sun Yat Sen U n i v e r s i t y of Medical Sciences). There is a regional d i f f e r e n c e in the p r e v a l e n c e rate, it is higher in northern or m o u n t a i n o u s regions where r i c k e t s is a s s o c i a t e d with long winter months and the lack of sunshine and vitamin D-rich foods. In the south, the c o n s i d e r e d opinion is p r i m a r i l y o v e r - p r o t e c t i o n (over d r e s s i n g in the winter and sheltering from the hot sun in the summer) of the one child.
III
112
D.L. YEUNG (iv) Zinc D e f i c i e n c y
Zinc d e f i c i e n c y is also a p r o b l e m a m o n g y o u n g c h i l d r e n in parts of China where the zinc c o n t e n t in the soil is low. In Beijing, the c a l c u l a t e d d i e t a r y zinc intake of k i n d e r g a r t e n c h i l d r e n r a n g e d from 4.5 to 5.5 mg daily, w h i c h is only 50% of the U.S. R e c o m m e n d e d Daily A l l o w a n c e (17). A d d i t i o n a l l y , 23% of the children, b e t w e e n 1 and 6 years, who were brought to a Child H e a l t h C l i n i c and 34% of c h i l d r e n s a m p l e d in n u r s e r i e s and k i n d e r g a r t e n had low hair zinc levels and were c o n s i d e r e d at risk of zinc d e f i c i e n c y , a l t h o u g h m e a s u r e m e n t of the level of zinc in the hair is g e n e r a l l y c o n s i d e r e d to be u n r e l i a b l e for the a s s e s s e m e n t of zinc status. N e v e r t h e l e s s , these c h i l d r e n were r e s p o n s i v e to zinc s u p p l e m e n t a t i o n as shown by d i s a p p e a r a n c e of pica and a n o r e x i a and i n c r e a s e d growth.
OTHER NUTRITIONAL PROBLEMS The f o l l o w i n g n u t r i t i o n a l p r o b l e m s are believed, i n f o r m e d sources in China, to exist but no s t a t i s t i c s their p r e v a l e n c e have been reported. (i)
Protein-Calorie
by on
Malutrition
A c c o r d i n g to the i m p r e s s i o n of n u t r i t i o n i s t s in China, p r o t e i n - c a l o r i e m a l n u t r i t i o n e x i s t s but the p r o b l e m is rare. Few cases of p r o t e i n - c a l o r i e m a l n u t r i t i o n are t r e a t e d a n n u a l l y in C h i l d r e n ' s H o s p i t a l s in d i f f e r e n t parts of China. Cases r e p o r t e d are m o s t l y in rural and r e m o t e areas of the country. (ii) C a l c i u m
Deficiency
C a l c i u m d e f i c i e n c y is s u s p e c t e d to be w i d e s p r e a d . A c c o r d i n g to n u t r i t i o n i s t s in China, the c a l c i u m c o n t e n t in d i e t s of infants and young c h i l d r e n is less than 50% of the C h i n e s e R e c o m m e n d e d Daily A l l o w a n c e s of 600 mg of c a l c i u m for c h i l d r e n less than 3 years of age (18). The p r o b l e m a p p e a r s to be r e l a t e d to the low levels of d a i r y p r o d u c t s in the d i e t s of the children. The c o n d i t i o n is a l s o t h o u g h t to be a s s o c i a t e d with the low vitamin D intake w h i c h may h i n d e r o p t i m a l u t i l i z a t i o n of the d i e t a r y calcium. (iii)
Vitamin
A Deficiency
V i t a m i n A - d e f i c i e n c y x e r o p t h a l m i a and b l i n d n e s s a f f e c t a large number of young c h i l d r e n in some South East A s i a n c o u n t r i e s (19). This p r o b l e m o f t e n a c c o m p a n i e s protein-calorie malnutrition. In most of these countries, v i t a m i n A -rich foods such as y e l l o w and green leafy v e g e t a b l e s , are p l e n t i f u l but because of poverty, c u l t u r a l t a b o o s and i g n o r a n c e they are not i n c l u d e d in the d i e t s of i n f a n t s and y o u n g children.
CHINESE INFANTSAND YOUNGCHILDREN
113
A c c o r d i n g to the World Bank, vitamin A d e f i c i e n c y is not a major p r o b l e m in China (3). However, C h i n e s e n u t r i t i o n i s t s believe that vitamin A d e f i c i e n c y does exist but m a i n l y in remote areas of China where v i t a m i n A- rich foods are scarce. (iv)
Deficiency
of the B-vitamins
The extent of vitamin B d e f i c i e n c y in China is not known. Beri-Beri and a r i b o f l a v i n o s i s were common p r o b l e m s prior to 1949 (20). T h i a m i n d e f i c i e n c y had become less of a p r o b l e m since the e l i m i n a t i o n of the use of p o l i s h e d rice. However, in recent years, b e c a u s e of the i m p r o v e d economy, p o l i s h e d rice is again b e c o m i n g popular. W h e t h e r or not Beri-Beri will r e s u r g e as a n u t r i t i o n a l p r o b l e m among infants and young c h i l d r e n r e m a i n s to be determined. Ariboflavinosis, at least marginal r i b o f l a v i n deficiency, is supected to be a p r o b l e m but the extent of the p r o b l e m is unknown. The suspicion is based on the low levels of d a i r y p r o d u c t s and meats in the d i e t s of infants and preschoolers. Among adolescents 12 to 19 years of age, r i b o f l a v i n d e f i c i e n c y has been found to be prevalent. In a study of 11,200 school children aged 12 to 19 y e a r s in the p r o v i n c e of G u a n g d o n g the mean daily r i b o f l a v i n intake was 0.45 mg, which is only 32% of the r e c o m m e n d e d d a i l y a l l o w a n c e for this age group (21). The main sources of r i b o f l a v i n were: rice (50%), vegetables (30%), soya bean p r o d u c t s (13%) and fish and meat (7%). The o b s e r v e d clinical signs of riboflavin d e f i c i e n c y were: scrotal d e r m a t i t i s (7.9% of boys), a n g u l a r s t o m a t i t i s (5.8% of boys, 2.7% of girls), c h e i l o s i s (8.0% of boys, 5.6% of girls), and m a g e n t a tongue (36.0% of boys, 40.8% of girls). Scrotal lesions were r e s o l v e d within 3 to 6 days after oral a d m i n i s t r a t i o n of 15 mg of r i b o f l a v i n per day. The r e s o l u t i o n of d e f i c i e n c y signs on the t o n g u e and lips p r o g r e s s e d more slowly.
NUTRITIONAL PROBLEMSTHAT ARE SUCCESSFULLYCONTROLLED In spite of the vastness of the country and the many n u t r i t i o n a l problems that exist it is worthy of note that China has s u c c e s s f u l l y c o n t r o l l e d two p r e v a l e n t and d e b i l i t a t i n g n u t r i t i o n a l diseases: Keshan D i s e a s e and E n d e m i c Goitre. (i)
Selenium
Selenium has been p r e v a l e n t
Deficiency deficiency, also known as Keshan in China for more than a h u n d r e d
Disease, years
114
D.L. YEUNG
(22,23). The d i s e a s e is found m a i n l y between the coastal zone of North Eastern China and the island zone of South W e s t e r n China in hilly lands but not in high m o u n t a i n s or plains. Keshan d i s e a s e affects 1% of children under i0 years of age and 95% of the cases occur in c h i l d r e n between 2 and 7 years of age (3). Over the years the incidence has d r a s t i c a l l y decreased. Between 1978 and 1980 less than 1 death per i00,000 p o p u l a t i o n was recorded. The r e m a r k a b l e d e c l i n e of the s e l e n i u m d e f i c i e n c y is due to a l t e r a t i o n of the diet to include high selenium foods, such as maize and soybeans or sodium selenite supplements (24). (ii)
Iodin e D e f i c i e n c y
A p p r o x i m a t e l y 300 million people live in known iodine d e f i c i e n t areas located in inland and m o u n t a i n o u s regions of China. In 1978, 34 million people were c o n s i d e r e d g o i t r o u s and 200,000 people were cretins (25,26,27). Since then, through iodination of salt and oil, i0 m i l l i o n individuals are said to be cured and 130 m i l l i o n are being p r o t e c t e d . The success in c o n t r o l l i n g iodine d e f i c i e n c y can be a t t r i b u t e d to several factors such as (a) the forceful and p r a g m a t i c action taken and (b) the tight g o v e r n m e n t control on salt movement and trade.
AN EMERGING PROBLEM-INFANT OBESITY The above d e s c r i b e d some of the n u t r i t i o n a l p r o b l e m s that exist among Chinese infants and young children. All the p r o b l e m s are due to nutrient deficiencies. An e m e r g i n g p r o b l e m that is of concern to health p r o f e s s i o n a l s is infant obesity. Because of the "One F a m i l y One Child" p o l i c y , C h i n e s e p a r e n t s dote on their c h i l d r e n . As i n d i c a t e d earlier, parents are w i l l i n g to spend more of their hard earned money to satisfy the wants of their infants. B e c a u s e of the lack of n u t r i t i o n knowledge, a fat baby is p e r c e i v e d to be a healthy baby. There is now a t e n d e n c y to o v e r f e e d infants with p e r c e i v e d and real n u t r i t i o u s foods and c o n f e c t i o n a r i e s that young children enjoy. This s i t u a t i o n d e s e r v e s m o n i t o r i n g e s p e c i a l l y if the foods are low in n u t r i e n t density.
SUMMARY China recognizes the importance of n u t r i t i o n to the health of her people (28). Infant n u t r i t i o n and the m a n u f a c t u r e of n u t r i t i o u s baby food are p r i o r i t i e s in p u b l i c health policies. Today, China is m a k i n g great strides in the m o d e r n i z a t i o n of agriculture, i n d u s t r y and science and technology. Potentially, there is enough food for all. The p o l i t i c a l system can control e q u i t a b l e d i s t r i b u t i o n of China's commodities (29). However, China can meet the n u t r i t i o n a l needs of her future g e n e r a t i o n s
CHINESE INFANTS AND YOUNGCHILDREN only if the nutritional needs of the population understood and appropriate measures are taken.
are clearly
The child health and welfare system in China is commendable. For a country having an annual birth rate of close to 20 million, the low infant mortality rate is remarkable (3). Every child is housed, clothed, fed and educated. By and large, Chinese infants and children are healthy. However their nutritional well being can be improved. Growth stunting, iron-deficiency anemia, vitamin D-deficiency rickets and zinc deficiency are prevalent. Vitamin A deficiency, calcium deficiency and deficiency of the B-vitamins exist, but the statistics on the extent of these nutritional problems are badly lacking. To improve the nutrition of infants and young children in China, a greater knowledge of their feeding and eating habits, and the prevalence and the etiology of the nutritional problems is needed. China has demonstrated that it can, in a relatively short time, eliminate serious and widespread nutritional problems. The case in point is the rapid resolution of Keshan Disease and Endemic Goitre. Having a good knowledge of the extent of the problem, China can implement forceful and pragmatic programs to fruitful solutions. Notwithstanding, the backing of the authorities is key. The measure of success of the birth control policy and the modernization programs in China is not the size of the population nor the technology that is gained, but the health and-well being of the future generations.
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