Salt consumption during the nutrition transition in South Korea

Department of Epidemiology School of Public Health Catholic University of Leuven Kapucijnenvoer 33 B-3000, Leuven Belgium E-mail: hugo.kesteloot{at}med.kuleuven.ac.be

Dear Sir:

We read with interest the article by Kim et al (1), which pointed out Korea's maintenance of its traditional diet, which is low in fat. It is evident, however, from Figure 4 in that article that the percentage of energy from fat increased rapidly from 7% in 1972 to 19% in 1995. These authors did not mention that the ratio of polyunsaturated to saturated dietary fat is still high in Korea compared with that in Western countries because of a high consumption of vegetable oil and fish oil (2). The ratio of vegetable to animal fat in the Korean diet is 1.4, very similar to that of Japan and markedly higher than that of the Russian Federation and the United Kingdom (3). A high ratio of polyunsaturated to saturated fat protects against atheromatous diseases. The authors also did not stress the traditionally high salt content of Korean food. The Korean population has one of the highest 24-h urinary sodium excretions in the world (4, 5) and one of the highest rates of mortality from stomach cancer (4) and cerebrovascular disease (6), which are positively associated with salt consumption (Table 1). For the Asian countries listed in Table 1, total mortality from cardiovascular disease is highest in Singapore, where the Chinese population has high serum cholesterol concentrations, presumably resulting from a high consumption of palm oil (8). Traditionally, Koreans had low serum cholesterol concentrations, comparable to those of northern Chinese (2). Only in Korea does cerebrovascular mortality account for >50% of total cardiovascular mortality. It would be interesting to know whether the progressive introduction of refrigerators in South Korean households has resulted in a decrease in salt consumption, as it did in Western countries.

We hope that the authors will continue to follow the evolution of nutrition in Korea, because it is still very different from that in the West, but will include dietary salt consumption in their analysis.

View this table:
TABLE 1.. Mortality in selected Asian countries in 1994 (per 100 000 per year)1  
REFERENCES

1. Kim S, Moon S, Popkin BM. The nutrition transition in South Korea. Am J Clin Nutr 2000;71:44–53.
2. Kesteloot H, Huang DX, Yang XS, et al. Serum lipids in the People's Republic of China: comparison of Western and Eastern populations. Arteriosclerosis 1985;5:427–33.
3. Food and Agriculture Organization of the United Nations. Food balance sheets. Rome: FAO, 1998.
4. Joossens JV, Hill MJ, Elliott P, et al. Dietary salt, nitrate and stomach cancer mortality in 24 countries. Int J Epidemiol 1996;25:494–504.
5. Kesteloot H, Park BC, Lee CS, Brems-Heyns E, Claessens J, Joossens JV. A comparative study of blood pressure and sodium intake in Belgium and in Korea. Eur J Cardiol 1980;11:169–82.
6. Sasaki S, Zhang XH, Kesteloot H. Dietary sodium, potassium, saturated fat, alcohol, and stroke mortality. Stroke 1995;26:783–9.
7. World Health Organization. World Health Statistics Annual. Geneva: WHO, 1995, 1996.
8. Hughes K, Yeo PPB, Lun KC, et al. Cardiovascular disease in Chinese, Malays, and Indians in Singapore. II. Differences in risk factor levels. J Epidemiol Community Health 1990;44:29–35.