PEDIATRICS Vol. 106 No. 5 Supplement November 2000, pp. 1274-1274

Overview of Complementary Feeding (Weaning) in Countries of Asia

Y. Yamashiro, MD

Department of Pediatrics Juntendo University School of Medicine 2-1-1, Hongo, Bunkyo-ku, Tokyo 113-8421, Japan

	ARTICLE

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Introduction

Asia contains both highly developed and developing countries and so there is a wide spectrum of nutritional problems in children receiving complementary foods reflecting the different socioeconomic and cultural backgrounds. Some countries such as Japan, Taiwan, and Korea have published detailed guidelines or recommendations or both for weaning but others, most of which are developing countries, have not done so. This diverse background leads to many potential research questions concerning complementary feeding in the countries of Asia. The following 2 research issues are explored in more detail.

1. The Prevalence and Prevention of Micronutrient Deficiencies

In children of the developing countries of Asia, intakes of iron and zinc are often below the daily intakes recommended in developed countries.¹ Cereals or starchy roots and tubers are commonly used during early infancy as a basis for gruels, which have a low-energy density and micronutrient content.

Pilot, carefully monitored, studies of strategies to enhance the micronutrient bioavailability and content of the plant-based complementary foods used are required. Several strategies may be assessed.^2,3 Germination, fermentation, and soaking can be used to enhance bioavailability of iron and zinc by reducing the content of phytic acid. Ascorbic acid is a good enhancer and may be added in the home as fruit/fruit juices. Animal and fish proteins enhance the absorption of iron, zinc, and copper,⁴ so that inclusion of even small amounts of meat, poultry, or fish (as dried flours) in complementary foods is an advantage.

In the developed countries of Asia, however, micronutrient deficiencies are more likely to be attributable to a low consumption of iron- and zinc-rich foods such as meat or fortified foods,⁵ or alternatively an excessive reliance on foods low in these nutrients, eg, formulas containing small amounts of zinc.⁶ More national studies of the prevalence of micronutrient deficiencies in the developed countries of Asia are required. These surveys should assess the size of any problem and its associated factors.

In both developing and developed countries, efficacy and effectiveness trials are needed to assess various intervention strategies that can be applied to communities with varying food customs, food availability, and price. It is probable that the most effective strategy will vary in different communities.

2. Secular Trend in the Prevalence of Allergic DiseasePossible Causes, Prevention, and Management

In the past 20 to 30 years, the prevalence of allergies has increased, particularly among children in highly developed countries,⁷ including Japan.⁸ Hypotheses to explain this trend^9,10 include a decline in exposure to infections, altered intestinal and other commensal flora and environmental stimuli by immunogenic saprophytic species (eg, mycobacteria¹¹), diphtheria, pertussis, tetanus, and other vaccinations. Many of these changes are occurring in Asian countries as they experience rapid economic development so that an increase in allergic disease might be expected.

Studies are desirable to determine if there is an actual increase in allergic disease and to determine the factors associated with or responsible for it. The opportunity to do this in developed countries has already more than likely been lost. If an increasing prevalence is confirmed, attention to the dietary factors currently thought to be important will be necessary, eg, breastfeeding, use of "hypoallergenic formulas," the timing of the introduction of egg, citrus fruit, and nuts in infants with a high-risk (positive family history) of allergy. The evidence for effective prevention by these dietary manipulations is far from clear, as study reports conflict.^12,13 The evaluation of any new policies introduced to Asian countries might provide an opportunity to resolve some of these conflicts of evidence.

Research Questions

In summary, 2 research questions relevant to Asian countries are important:

1. The prevalence and prevention of micronutrient deficiencies.
2. Secular trend in the prevalence of allergic diseasepossible causes, prevention, and management.

	REFERENCES

Top Article References

1. Gibson RS Zinc nutrition in developing countries. Nutr Res Rev. 1994; 7:151-173
2. Gibson RS, Ferguson EL Nutrition invervention strategies to combat zinc deficiency in developing countries. Nutr Res Rev. 1998; 10:1-18
3. Gibson RS, Ferguson EL. Food processing method for improving the content and bioavailability of home-based and commercially available complementary foods. In: Micronutrient Interactions: Impact of Child Health and Nutrition. Washington, DC: ILSI Press, International Life Science Institute; 1998:50-57
4. Fairweather-Tait S, Hurrell RF Bioavailability of minerals and trace elements. Nutr Res Rev. 1996; 9:295-324
5. Nakano T, Idota T, Nakajima I The survey of nutrient intake from weaning food in Japan. Jpn J Pediatr Gastroenterol Nutr. 1995; 9:16-27
6. Higashi A, Ikeda T, Uehara I, Matsuda I Effect of low content zinc and copper formula on infant nutrition. Eur J Pediatr. 1982; 138:237-240
7. Peat JK, van den Berg RH, Green WF, Changing prevalence of asthma in Australian children. Br Med J. 1994; 308:1591-1596
8. Nakagawa T The prevalence rate of asthma is 4-6% in childrenepidemiology of asthma. Scope. 1994; 33:12-13
9. Martines FD Role of viral infections in the inception of asthma and allergic diseases during childhood: could they be protective? Thorax. 1994; 49:1189-1191
10. Erb KJ Atopic disorders: a default pathway in the absence of infection? Immunol Today. 1999; 20:317-322
11. Rook GAW, Stanford JL Give us this day our daily germs. Immunol Today. 1998; 1:113-116
12. Zeiger RS, Heller S The development and prediction of atopy in high-risk children: follow-up at age 7 years in a prospective randomized study of combined maternal and infant food allergy avoidance. J Allergy Clin Immunol. 1995; 95:1179-1190
13. Lindfors A, Enocksson E Development of atopic disease after early administration of cow milk formula. Allergy. 1988; 43:11-16