Efficacy and safety of a dieckol-rich extract (AG-dieckol) of brown algae, Ecklonia cava, in pre-diabetic individuals: a double-blind, randomized, placebo-controlled clinical trial

The effects of 12 weeks of supplementation with a dieckol-rich extract (AG-dieckol) from brown algae, Ecklonia cava, on glycemic parameters, serum biochemistry, and hematology were investigated in this study. Eighty pre-diabetic male and female adults were enrolled in a randomized, double-blind, placebo-controlled trial with parallel-group design. Subjects were randomly allocated into two groups designated as placebo and AG-dieckol (1500 mg per day). Compared with the placebo group, the AG-dieckol group showed a significant decrease in postprandial glucose levels after 12 weeks. The AG-dieckol group also showed a significant decrease in insulin and C-peptide levels after 12 weeks, but there was no significant difference between the AG-dieckol and placebo groups. There were no significant adverse events related to the consumption of AG-dieckol, and biochemical and hematological parameters were maintained within the normal range during the intervention period. In conclusion, these results demonstrate that AG-dieckol supplementation significantly contributes to lowering postprandial hyperglycemia and in reducing insulin resistance. Furthermore, we believe that based on these results the consumption of phlorotanninrich foods such as marine algae may be useful for the treatment of diabetes.