Abstract
Japanese food is of interest worldwide as healthy food. However, comparison of Japanese food with European and American food has not been performed using DNA microarray analysis. In this study, we examined differences in gene expression levels in the liver of rats fed “Japanese food” or “American food” using a DNA microarray. Two meals were cooked based on a menu of Japanese food and American food. The cooked meals were prepared to a freeze-dried powder and given to rats for three weeks as test diets. Total RNA was then extracted from rat liver and used in DNA microarray analysis. The expression levels of stress response genes were lower in rats fed Japanese food compared to those fed American food, and expression of genes of the sugar and lipid metabolism system was higher in rats fed Japanese food. Expression of genes associated with cholesterol catabolism increased markedly in rats fed Japanese food, although the ingested lipid content was low, and cholesterol accumulation in rat liver was prevented. Therefore, the results suggest that Japanese food is healthy and profitable compared with American food due to activation of metabolism and reduction of stress.
