Tuna extract reduces serum uric acid in gout-free subjects with insignificantly high serum uric acid: A randomized controlled trial

Long-term reduction of serum urate levels is vital in the treatment of gout. However, it is difficult to convince gout-free individuals of the necessity of treatment as few appropriate over-the-counter remedies and dietary supplements are available. Therefore, the present study aimed to investigate the antihyperuricemic efficacy and safety of a tuna extract containing the imidazole compounds to evaluate its potential as a functional food ingredient. A randomized, 4-week, double-blind, placebo-controlled study was conducted. A total of 48 male gout-free subjects with insignificantly high serum uric acid were randomly assigned to low- and high-dose tuna extract groups or a placebo group. The efficacy of the extract was assessed by measuring serum uric acid levels. Furthermore, a safety assessment was performed by physical parameters, hematology, blood biochemistry and urinalysis. The results indicated that the uric acid level was decreased at week 4 during the intervention in the tuna extract groups (low and high dose, -0.23 and -0.34 mg/dl, respectively) compared to the placebo group (-0.07 mg/dl). At week 4 after the intervention, a significant reduction in uric acid levels (-0.41 mg/dl; P<0.05) was observed in the high-dose tuna extract group compared with the placebo group (+0.11 mg/dl). No dose-related adverse events were observed during and following the intervention. Therefore, the present results suggest that oral administration of tuna extract containing the imidazole compounds has hypouricemic activity with no undesirable side effects.