Seaweed Fucoxanthin Supplementation Improves Obesity Parameters in Mild Obese Japanese Subjects

Abstract

Background: Fucoxanthin is a seaweed xanthophyll that has demonstrated an anti-obesity effect in rodents. However, clinical investigations of its influence on mildly obese subjects has not been performed. We conducted a clinical trial of fucoxanthin supplementation in Japanese obese subjects. 

Methods: We examined the effect of fucoxanthin (1 or 3 mg daily) in a double-blind placebo-controlled study. Capsules containing fucoxanthin or placebo capsules were administered for 4 weeks to male and female Japanese adults with a body mass index (BMI) of more than 25 kg/m². Before and after treatment, the body weight, body composition, abdominal fat area, and the circumferences of the neck, arm, and thigh were evaluated.

Results: There was significant reduction of the relative (ratio versus before treatment) body weight, BMI, and visceral fat area in the 3 mg/day fucoxanthin group compared to the placebo group. Relative values of total fat mass, subcutaneous fat area, waist circumference, and right thigh circumference were also significantly lower in the 1 mg/day fucoxanthin group than the placebo group. A significant decrease of the absolute right thigh circumference was noted in the 1 mg/day fucoxanthin group compared to the placebo group. In the subjects ingesting fucoxanthin, there were no abnormalities of the blood pressure, pulse rate, blood parameters, and urinalysis parameters, which thereby suggests adverse effects. 

Conclusions: Fucoxanthin reduced body weight, BMI, and abdominal fat by acting on both visceral and subcutaneous fat. Consequently, Fucoxanthin may be able to improve a moderate overweight state in both men and women. 

Keywords: Randomized, double-blind, placebo-controlled crossover trial; fucoxanthin; body mass index; body weight; subcutaneous fat; adipose tissue