抄録
Our previous experimental results have shown that a mixture of thiamin, arginine, caffeine and citric acid (TACC) has an enhancement effect on fat metabolism in mice and human. In this study we examined the effect of tea ingestion, which was supplemented with TACC, on energy expenditure during a rest and an exercise period from the viewpoint of fat metabolism (utilization) in healthy subjects. A single-blind, placebo-controlled, crossover study was carried out to compare the energy expenditure after ingestion of TACC-supplemented tea (thiamin, arginine, caffeine, and citric acid; 1.1, 1240, 52, and 540mg, respectively) or control tea on two consecutive days, in 10 healthy male and female subjects (aged 21-27y) in experiment 1. After the tea ingestion, subjects sat on a chair for 30 min followed by treadmill walking (5km/hr) for 30 min. Respiratory quotient (RQ) and oxygen consumption (VO2) were measured during rest and exercise periods. A double-blind, placebo-controlled, crossover study was performed in 14 healthy female subjects (aged 21-22y) in experiment 2, of which study design was the same as that of experiment 1 except for an additional measurement of RQ and VO2 before ingestion of the tea for 30 min in the sitting position. As results, total energy expenditure and fat oxidation were similar between the two cases (ingestion of control tea and TACC-tea) during the rest period after tea ingestion both in experiment 1 and experiment 2. On the contrary, treadmill walking resulted in about three-fold increase in total energy expenditure; however, fat oxidation during the exercise was significantly greater in the case of TACC-tea than in the control tea case in the both experiments. This effect of TACC-supplementation, enhanced fat oxidation and energy expenditure, seemed to be positively proportional to subjects' Body Mass Index.
