Naomi Omi, Hideki Shiba, Eisaku Nishimura, Sakuka Tsukamoto, Hiroko Maruki-Uchida, Masaya Oda, Minoru Morita
Journal: Journal of the International Society of Sports Nutrition 2019;16(1):39
PMID: 31500646
Enzymatically modified isoquercitrin (EMIQ) is a modified form of rutin and quercetin, two plant flavonoids with antioxidant properties, which is better absorbed and has been shown to support muscle building in animal models. The aim of this double-blind, placebo-controlled trial was to examine the effects of EMIQ on body composition and antioxidant status of American football players who undergo regular strong exercise training. Participants, 39 young male Japanese University students, consumed either 20g per day of whey protein powder or 20g of whey protein powder with 42mg of EMIQ 6 times per week after training for 4 months. There was a statistically significantly higher increase in lower limb muscle and fat-free mass in the EMIQ group compared to whey protein alone. There were no differences in total lean body mass and fat mass between the groups. EMIQ supplementation increased antioxidant status compared to the whey only group. The authors state that the results suggest that EMIQ supplementation may optimize the exercise effect and intensify muscle building in humans and discuss suppression of oxidative stress as a possible mechanism.
BACKGROUND
Enzymatically modified isoquercitrin (EMIQ), a water-soluble quercetin, has been shown to intensify muscle hypertrophy in mice. We investigated the effect of EMIQ in supplementary protein powder on athlete body composition.
METHODS
Forty Japanese males who played American football (age: 19.8 ± 1.4 years; body height: 174.1 ± 6.0 cm; body mass: 75.5 ± 10.7 kg) were assigned to a randomized, placebo-controlled, double-blind trial of parallel group. Participants received either EMIQ in whey protein (EW, n = 19) or contrast whey protein (W, n = 20) 6 days per week over 4 months. Body composition was assessed using dual-energy X-ray absorptiometry. Markers of oxidative stress, derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP), were assessed using a free radical analytical system. Data were analyzed using a univariate and repeated measures general model statistics.
RESULTS
After 4 months, changes in lower limb fat-free mass and muscle mass were significantly greater in the EW group than in the W group (mean change ±95% CI; W: 324.1 ± 284.3, EW: 950.3 ± 473.2, p = 0.031, W: 255.7 ± 288.6, EW: 930.9 ± 471.5, p = 0.021, respectively). Moreover, the EW group exhibited a significantly higher BAP/d-ROMs ratio, antioxidation index, than the W group after 4 months (mean change ± SD; W: 8.8 ± 1.1, EW: 10.3 ± 2.8; p = 0.028). No significant differences in body mass, lean body mass, fat mass, or lower limb fat mass were observed between the groups.
CONCLUSION
Ingestion of EMIQ in supplementary protein powder for 4 months exerts antioxidant effects and increases muscle mass among American football players.
TRIAL REGISTRATION
University Hospital Medical Information Network Clinical Trial Registry, UMIN000036036 . Retrospectively registered in 2019.
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