(14) EFFECTS OF ASTAXANTHIN ON CARDIORESPIRATORY FITNESS AND CARDIOMETABOLIC HEALTH PARAMATERS AMONG CAREER FIREFIGHTERS

Firefighters are at risk for cardiovascular disease (CVD) due to increased oxidative stress (OS), and poor cardiorespiratory fitness and cardiometabolic health profiles. Astaxanthin (AX), a naturally occurring carotenoid, possesses potent antioxidant properties and has been purported to increase endogenous antioxidant status, reduce OS markers, and improve aerobic fitness capacity following supplementation. Firefighters may benefit from AX supplementation; however, no study to-date has assessed the impacts of AX among the firefighter community.

Purpose: This study examined the effects of 4-weeks of AX supplementation on aerobic fitness and cardiometabolic health parameters (i.e., OS markers).

Methods: In a randomized, double-blinded, placebo-controlled, crossover fashion, 15 career, male firefighters (age: 34.5±7.4 yr, body mass: 95.6±12.0 kg, height: 177.7.8±7.0 cm, VO_2peak: 41.0±5.9 ml/kg/min) ingested 12 mg/d of AX (AstaReal^®, Burlington, NJ) or placebo (PLA [sunflower oil]) for 4-weeks separated by a 14-day washout period, while participating in a standardized resistance and conditioning program. After each supplementation period, a fasting blood sample was obtained. Participants then completed an incremental cardiorespiratory exercise test to exhaustion and a post-exercise blood sample was obtained. Data were analyzed using general linear model multivariate analysis with repeated measures and partial eta squared (η_p²) values to assess effect-size. Mean changes from baseline with 95% confidence intervals (mean [LL, UL]) were used to assess clinical significance.

Results: Although some time effects were observed, no significant treatment x time interactions were noted for advanced oxidation protein products (AOPP), advanced glycation end products (AGE), adiponectin, glucose, or whole blood or serum clinical chemistry panels (white cells, red cells, blood lipids, glucose, or muscle and liver enzymes). A trend was noted for blood AGE with PL having lower concentrations compared to AX (-0.357 [-.078, 0.70] µg/mL, p< 0.098, η_p²=0.095, medium to large effect). Percent ventilatory anaerobic threshold (VANT) following AX supplementation was significantly higher compared to PL (4.84 [0.27, 9.41] %, p< 0.039, η_p²=0.114, large effect). No significant differences were noted for the remaining cardiorespiratory measures or the frequency or severity of side effects between treatments. CONCLUSIONS: Four weeks of AX supplementation improved VANT but had no statistically significant effects on blood OS markers, markers of cardiometabolic health, or clinical blood chemistry variables. PRACTICAL APPLICATION: AX may have some ergogenic benefits, as noted by the improved VANT, that can benefit firefighter physical performance. In addition, AX may serve as a natural antioxidant for firefighters at risk of OS: however, more research is needed to determine if AX supplementation affects markers of cardiometabolic health in this population. Firefighters may consider the utilization of natural antioxidants to improve cardiorespiratory fitness parameters and cardiometabolic health.

Acknowledgements:

ACKNOWLEDGEMENTS: We would like to thank the Bryan, Texas Fire Department for their participation in this study. This study was funded by AstaReal^®.