Effects of black garlic supplementation on exercise-induced physiological responses

Abstract

Antioxidants, including garlic, are beneficial to suppress exercise-induced oxidative stress (EIOS), and black garlic (BG) is a recently-developed whole food with strong antioxidant properties. This study investigated the effects of BG supplementation on physiological responses, especially on EIOS and recovery of muscle function. Nineteen untrained males were assigned to either a BG group (n=11, GG) or placebo group (n=8, PG), with a similar age and body mass index, during a 14-day-study. Before and after eccentric exercise of elbow flexors, we measured muscle function, blood and urinary biochemistries concerning muscle injury proteins, inflammatory cells, cytokines, reactive oxygen metabolites (d-ROMs), and antioxidative potential (BAP). Maximal voluntary contraction strength decreased by 35% immediately post-exercise in both groups. Recovery of circumference of biceps brachii in GG was significantly faster than in PG during 3-7 days post-exercise. d-ROMs level was lower in GG than in PG during 1-3 days post-exercise, but no significant difference in BAP was observed between groups. Exercise induced leukocytosis, and monocytes, lymphocytes, and neutrophils all exhibited significant time effects. A significantly greater creatine kinase level was found on day 3 post-exercise in PG than in GG. Lipid peroxide concentration was lower during 3-7 days post-exercise in GG than in PG, and the 8-iso-prostaglandin F_2α level was significantly greater in PG than in GG at every post-exercise point. These results suggest that BG supplementation had certain effects on suppression of physiological responses, including EIOS, and might promote the recovery of edema in injured tissue.