Ergogenic and Antioxidant Effects of Spirulina Supplementation in Humans

Abstract and Introduction

Abstract

Purpose: Spirulina is a popular nutritional supplement that is accompanied by claiMSS for antioxidant and performance-enhancing effects. Therefore, the aim of the present study was to examine the effect of spirulina supplementation on (i) exercise performance, (ii) substrate metabolism, and (iii) blood redox status both at rest and after exercise.
Methods: Nine moderately trained males took part in a double-blind, placebo-controlled, counterbalanced crossover study. Each subject received either spirulina (6 g·d⁻¹) or placebo for 4 wk. Each subject ran on a treadmill at an intensity corresponding to 70%-75% of their V·O_2max for 2 h and then at 95% V·O_2max to exhaustion. Exercise performance and respiratory quotient during exercise were measured after both placebo and spirulina supplementation. Blood samples were drawn before, immediately after, and at 1, 24, and 48 h after exercise. Reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG, thiobarbituric acid-reactive substances (TBARS), protein carbonyls, catalase activity, and total antioxidant capacity (TAC) were determined.
Results: Time to fatigue after the 2-h run was significantly longer after spirulina supplementation (2.05 ± 0.68 vs 2.70 ± 0.79 min). Ingestion of spirulina significantly decreased carbohydrate oxidation rate by 10.3% and increased fat oxidation rate by 10.9% during the 2-h run compared with the placebo trial. GSH levels were higher after the spirulina supplementation compared with placebo at rest and 24 h after exercise. TBARS levels increased after exercise after placebo but not after spirulina supplementation. Protein carbonyls, catalase, and TAC levels increased similarly immediately after and 1 h after exercise in both groups.
Conclusions: Spirulina supplementation induced a significant increase in exercise performance, fat oxidation, and GSH concentration and attenuated the exercise-induced increase in lipid peroxidation.

Introduction

Spirulina (Spirulina platensis) is a photosynthetic cyanobacterium that possesses biological activity and is widely cultivated to produce nutritional supplements.^[26] Spirulina is rich in essential amino acids and fatty acids (palmitic acid, linoleic acid, and γ-linolenic acid), vitamin C, vitamin E, and selenium.^[26] Recently, attention has been placed on the antioxidant potential of spirulina. Indeed, many of the chemical components of spirulina, such as phenolic compounds, tocopherols, β-carotenes, and phycocyanins exhibit antioxidants properties.^[11] For instance, it has been reported that spirulina supplementation with ginseng decreased lipid peroxidation and increased the levels of reduced glutathione (GSH), superoxide dismutase, and glutathione peroxidase in the kidney of rats.^[21]

Exercise promotes the production of reactive oxygen and nitrogen species (RONS). Growing evidence indicates that RONS contribute to muscle fatigue.^[14] To protect against exercise-induced oxidative damage, cells contain endogenous cellular defense mechanisMSS to control the levels of RONS.^[37] Furthermore, exogenous dietary antioxidants interact with endogenous antioxidants and form a network of cellular antioxidants.^[37] The fact that exercise-induced RONS production can contribute to muscle fatigue^[14]) has resulted in numerous investigations examining the effects of different antioxidants (e.g., vitamin C or N-acetylcysteine) on human redox status and exercise performance (e.g., [2,28]). However, comparatively few researchers have studied the effect of foods rich in antioxidants on oxidative stress provoked by exercise.^[34,45] Thus, the extent to which foods rich in antioxidants (such as spirulina) modify the redox status responses induced by exercise is largely unknown.

We found only one study that examined the effects of spirulina on redox status and exercise performance.^[25] However, the blood samples after spirulina supplementation and exercise were compared with the resting blood samples making it difficult to discern the spirulina effect. Nowadays, spirulina is a very popular nutritional supplement for humans and is accompanied by claiMSS for antioxidant and performance-enhancing effects.^[12] These claiMSS are extrapolated by the findings of in vitro and animal studies^[11,21] but have not been substantiated concerning humans. Therefore, the aim of the present study was to examine the effect of spirulina supplementation on (i) exercise performance, (ii) substrate metabolism, and (iii) blood redox status both at rest and after exercise.

Med Sci Sports Exerc. 2010;42(1):142-151. © 2010 

Cite this: Ergogenic and Antioxidant Effects of Spirulina Supplementation in Humans - Medscape - Jan 01, 2010.