The Effect of the Dried-Bonito Broth on Blood Pressure, 8-Hydroxydeoxyguanosine (8-OHdG), an Oxidative Stress Marker, and Emotional States in Elderly Subjects

Dried-bonito broth (DBB, katsuo-bushi dashi) is commonly used in Japanese cuisine, and is also used as a traditional remedy for recovery from fatigue and improvement of blood circulation. To clarify the effect of DBB on blood pressure, oxidative stress and emotional states, a randomized crossover human trial was performed. Twenty-seven elderly Japanese subjects ingested DBB or water for one month. Measurement of blood pressure and urinary 8-hydroxydeoxyguanosine (8-OHdG) and evaluation of emotional states were performed before and after the ingestion periods. The changes in systolic blood pressure (SBP) during DBB ingestion was significantly lower than that during water ingestion (p = 0.037). Urinary 8-OHdG significantly decreased during DBB ingestion (p = 0.0002). Evaluation of emotional states indicated that composure significantly improved during DBB ingestion (p = 0.034). These results suggest that the daily ingestion of DBB lower SBP, reduce urinary 8-OHdG and might improve emotional states in elderly subjects.