Comparison of lymphocyte DNA damage levels and total antioxidant capacity in Korean and American diet

This study aims to measure the antioxidant capacity of Korean diet (KD) with American diet (AD) as a control group and to examine the DNA damage reduction effect on human lymphocytes. The KD applied in this study is the standard one-week meals for Koreans (2,000 kcal/day) suggested by 2010 Dietary Reference Intakes for Koreans. The AD, which is the control group, is a one-week menu (2,000 kcal/day) that consists of foods that Americans would commonly take in according to the National Health and Nutrition Examination Survey. The antioxidant capacity of each menu was measured by means of the total phenolic assay and 3 antioxidant activity assays (2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, trolox equivalent antioxidant capacity (TEAC), Oxygen radical absorbance capacity (ORAC )), while the extent of lymphocyte DNA damage was measured by means of the comet assay. When measured by means of TEAC assay, the antioxidant capacity of the KD of the day was higher than that of the AD ( < 0.05) while there was no significant difference in total phenolic contents and DPPH and ORAC assays. The lymphocyte DNA damage protective effect of the KD was significantly higher than that of the AD ( < 0.01). As for the one-week menu combining the menus for 7 days, the total phenolic assay ( < 0.05) and antioxidant capacity ( < 0.001, DPPH; < 0.01, TEAC) of the KD menu were significantly higher than those of the AD menu. Likewise, the DNA damage reduction rate of the Korean seven-day menu was significantly higher than that of the American menu ( < 0.01). This study demonstrates that the high antioxidant capacity and DNA damage protective effect of KD, which consists generally of various plant foods, are higher than those of typical AD.