Urine Organic Acids Can Determine the Metabolic Effects of Traditional Korean Diet, a Cardiometabolic Diet

Objectives Urine organic acids are water-soluble chemical compounds excreted in the urine that are intermediates in many metabolic pathways. Because excess metabolites are excreted in the urine, they may reflect the metabolic status. We investigated whether urine organic acids can determine the metabolic influence of traditional Korean diet (K-diet), a cardiometabolic diet. Methods Fifty two healthy premenopausal women were recruited into a 2 × 2 crossover study with two different diets, K diet and control diet (Westernized current Korean diet). Each diet was provided alternately to all subjects for 1 month with 1 month washout period. Blood and urine samples were collected with anthropometric measurements. Sixty five urine organic acids were measured by LC-MS/MS. Results In the K-diet group, the mean difference of triglyceride (−6.58 ± 4.80 vs −26.35 ± 6.05 mg/dL, P = 0.012), total cholesterol (−12.77 ± 2.78 vs −30.02 ± 2.65 mg/dL, P < 0.001) and LDL- cholesterol (−5.52 ± 2.30 vs −15.88 ± 2.29 mg/dL, P = 0.002) were significantly lower compared to the control group. Body weight and body mass index were also lowered in the K-diet group. Among 65 urine organic acids, TCA cycle associated α-ketoglutarate (21.73 ± 1.27 vs 19.05 ± 1.15 ug/mg creatinine, P = 0.008), malate (1.61 ± 0.10 vs 1.34 ± 0.09, P = 0.008) and isocitrate (22.90 ± 0.68 vs 21.27 ± 0.54, P = 0.014) were lowered in the K-diet group, while citrate (249.16 ± 16.96 vs 324.42 ± 21.18, P = 0.001) and furmarate (0.51 ± 0.03 vs 0.65 ± 0.06, P = 0.029) were elevated in the control group. α-Keto-β-methylvalerate (1.46 ± 0.09 vs 1.09 ± 0.07, P = 0.001), α-ketoisovalerate (0.22 ± 0.02 vs 0.16 ± 0.02, P = 0.012) and methylmalonate (1.30 ± 0.06 vs 1.00 ± 0.06, P < 0.001), which are associated with branched chain amino acid metabolism, were decreased in the K-diet group. Adipate (0.90 ± 0.07 vs 0.65 ± 0.04, P < 0.001) and α-ketoisocaproate (0.46 ± 0.02 vs 0.38 ± 0.02, P = 0.002), which are associated with fatty acid metabolism, were also decreased in the K-diet group. Conclusions K-diet improves clinical parameters and alters urine organic acids associated with TCA cycle and metabolisms of fatty acids and branched-chain amino acid, suggesting that urine organic acids can be useful endpoints to determine the metabolic effects of K-diet and even other diets. Funding Sources Korea Food Research Institute.