{'fraction_non_alphanumeric': 0.02210587550901687, 'fraction_numerical': 0.012798138452588714, 'mean_word_length': 5.209386281588448, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Impact of polyphenols on physiological stress and cardiac burden in marathon runners - results from a substudy of the BeMaGIC study.

Both physiologic stress and chronic heart disease are associated with increased systemic levels of chromogranin A (CGA) and NT-proBNP. Marathon running causes physiological stress and imposes a significant cardiac burden. Polyphenol-rich Mediterranean and Asian diets have been demonstrated to exert beneficial effects on the cardiovascular system. In this study we investigated whether pretreatment with a polyphenol beverage could attenuate the physiological and cardiac stress associated with a marathon. In the BeMaGIC trial, 277 athletes were randomized into 2 groups in a double-blinded fashion, receiving 1-1.5 L/day of the same beverages either with (study beverage) or without (placebo) polyphenol enrichment (approximately 400 mg of gallic acid equivalents per day of a complex mixture of polyphenols). Blood samples were taken 3 weeks and 1 day before, and immediately, 24 h, and 72 h after running a marathon. In our current substudy, CGA and NT-proBNP levels were analyzed by ELISA in the fastest 18 and the slowest 22 runners. CGA and NT-proBNP levels increased significantly immediately after the marathon and returned to baseline at 72 h after the marathon. Neither CGA nor NT-proBNP differed significantly between athletes receiving study beverage versus placebo. Separating our cohort into fast and slow runners did not reveal any significant difference regarding CGA or NT-proBNP levels between groups. Our study provides no evidence that polyphenol supplementation attenuates marathon running-induced physiological stress and cardiac burden in fast or slow runners.