Effects of daily intake of Harudori-kombu: A randomized, double-blind, placebo-controlled, parallel-group study

Abstract

Background: Kombu (Laminariaceae) is traditionally consumed in Japan. “Harudori-kombu” is young kombu harvested in spring. Harudori-kombu contains functional components, such as fucoxanthin—a carotenoid—which confer various biological effects. This study aimed to test the intake of Harudori-kombu and the effects on adiponectin levels and body fat. Methods: In this study, we investigated effects of the continuous intake of dried Harudori-kombu (2.0 g/day) for 6 weeks. We conducted a randomized, double-blind, placebo-controlled, parallel-group study including 70 healthy Japanese subjects with body mass index between 22 and 30 kg/m2 and low-density lipoprotein cholesterol levels between 120 and 160 mg/dL. Subjects were randomly assigned to either Harudori-kombu group or placebo group. Subjects ingested 9 capsules per day for 6 weeks. We conducted medical interviews, vital sign examinations, and blood sampling at weeks 0 (baseline), 2, and 6. Moreover, we assessed body composition at weeks 0 and 6. Results: Harudori-kombu intake did not improve the lipid profile but did reduce body fat. In addition, adiponectin levels were significantly improved. Conclusions: Harudori-kombu intake showed beneficial health effects, such as reduction in body fat and improvement of adiponectin levels and was deemed safe at the dose administered in this study.