Tomato powder is more effective than lycopene to alleviate exercise-induced lipid peroxidation in well-trained male athletes: randomized, double-blinded cross-over study.

BACKGROUND: Consumption of nutritional supplements to optimize recovery is gaining popularity among athletes. Tomatoes contain micronutrients and various bioactive components with antioxidant properties. Many of the health benefits of tomatoes have been attributed to lycopene encouraging athletes to consume pure lycopene supplements. The aim of this study was to compare the effect of tomato powder and lycopene supplement on lipid peroxidation induced by exhaustive exercise in well-trained male athletes. METHODS: Eleven well-trained male athletes participated in a randomized, double-blinded, crossover study. Each subject underwent three exhaustive exercise tests after 1-week supplementation of tomato powder (each serving contained 30 mg lycopene, 5.38 mg beta-carotene, 22.32 mg phytoene, 9.84 mg phytofluene), manufactured lycopene supplement (30 mg lycopene), or placebo. Three blood samples (baseline, post-ingestion and post-exercise) were collected to assess total anti-oxidant capacity (TAC) and variables of lipid peroxidation including malondialdehyde (MDA) and 8-isoprostane. Data were analyzed using repeated-measures of ANOVA at P < 0.05. RESULTS: Tomato powder enhanced total antioxidant capacity (12% increase, P = 0.04). Exhaustive exercise, regardless of supplement/ placebo, elevated MDA and 8-isoprostane levels (P < 0.001). The elevation of 8-isoprostane following exhaustive exercise was lower in the tomato powder treatment compared to the placebo (9% versus 24%, p = 0.01). Furthermore, following exhaustive exercise MDA elevated to a lower extent in tomatoe powder treatment compared to the placebo (20% versus 51%, p = 0.009). However, such differences were not indicated between lycopene and placebo treatments (p > 0.05). CONCLUSION: Beneficial effects of tomato powder on antioxidant capacity and exercise-induced lipid peroxidation may be brought about by a synergistic interaction of lycopene with other bioactive nutrients rather than single lycopene.

High doses of sodium nitrate prior to exhaustive exercise increases plasma peroxynitrite levels in well-trained subjects: randomized, double-blinded, crossover study.

The aim of this study was to investigate the effect of different doses of pre-workout sodium nitrate supplementation on nitric oxide, peroxynitrite levels, and performance parameters. Ten well-trained male subjects participated in a randomized, double-blinded, crossover study. They ingested 8, 16, and 24 mmol sodium nitrate or placebo (NaCl) dissolved in water at 2.5 h before an incremental exercise test. Respiratory gases (oxygen consumption, carbon dioxide production, respiratory exchange ratio) were measured throughout the exercise trials and 3 blood samples (pre-ingestion, 2.5 h post-ingestion and postexercise) were taken to analyze nitrate/nitrite (NOx) and peroxynitrite levels. Data were analyzed using repeated-measures ANOVA at significance level of P < 0.05. NOx levels significantly increased following sodium nitrate ingestion compared with placebo (placebo: 40.86 ± 10.7 µmol/L, 8 mmol: 203.69 ± 25.1 µmol/L, 16 mmol: 289.41 ± 30.1 µmol/L, and 24 mmol: 300.95 ± 42.4 µmol/L, respectively) (P = 0.0001). However, this did not induce any significant change in oxygen consumption (P = 0.351), blood lactate concentration (P = 0.245), and time-to-exhaustion (P = 0.147). Peroxynitrite levels were similar compared with placebo when participants ingested 8 and 16 mmol of inorganic nitrate but a significant increase was observed after exercise at maximal intensity when participants were supplemented with 24 mmol (mean = 14.60 ± 1.3 µmol/L, P = 0.001). Pre-workout ingestion of high dose of sodium nitrate (24 mmol) induced peroxynitrate formation, a marker of oxidative stress. Caution must be taken regarding administration of higher doses before benefits or adverse effects are established in this population.