Effects of Algae-Based Supplementation on Metabolic, Oxidative, and Inflammatory Markers in Physically Active Adults: A Pilot Randomized Controlled Trial

Algae-based supplements are gaining attention for their potential metabolic, antioxidant, and anti-inflammatory properties in sports nutrition. Methods: A 30-day pilot randomized controlled trial was conducted in 70 healthy male athletes (mean age 25.4 ± 4.9 years) from competitive soccer and handball teams. Participants were randomly assigned to a supplementation group (6 g/day of Ulva-derived algae powder) or a control group. Both groups followed identical training routines and adhered to standardized nutritional recommendations, including macronutrient distribution and permitted supplements (e.g., isotonic drinks, protein shakes). Biochemical markers analyzed at baseline and post-intervention included HbA1c, lipid profile, malondialdehyde (MDA), catalase, myeloperoxidase (MPO), erythrocyte sedimentation rate (ESR), and cortisol. Genetic polymorphisms related to metabolic traits were also assessed. Results: Significant group × time interactions (p < 0.001) were observed for HbA1c, LDL, triglycerides, MDA, MPO, ESR, and cortisol, all of which improved in the algae-supplemented group. Correlation analysis revealed associations between HbA1c and LDL/TG as well as between cortisol and MPO. No significant genetic modulation of responses was detected, although a trend was noted for cortisol variation and insulin resistance risk. Conclusions: Algae-based supplementation led to favorable metabolic, oxidative, and inflammatory changes. These findings suggest its potential utility as a nutritional strategy to support recovery in athletes during periods of high training load or competition.