Dr. Ron’s Research Review – December 18, 2019

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This week’s research review focuses on Fenugreek as an aromatase inhibitor.

A study determined the effects of an aromatase and 5-α reductase inhibitor (AI) on strength, body composition, and hormonal profiles in resistance-trained men. (Wilborn et al., 2010)
Thirty resistance-trained men were randomly assigned in a double-blind manner to ingest 500 mg of either a placebo (PL) or AI once per day for 8 wk. Participants participated in a 4-d/wk resistance-training program for 8 wk. At Weeks 0, 4, and 8, body composition, 1-repetition-maximum (1RM) bench press and leg press, muscle endurance, anaerobic power, and hormonal profiles were assessed. Statistical analyses used a 2-way ANOVA with repeated measures for all criterion variables (p ≤ .05).
Participants were matched into one of two groups according to total body weight. They were then randomly assigned in a double-blind manner to ingest capsules containing 500 mg of placebo (maltodextrin; PL) or 500 mg of T. foenum-graecum (standardized for Grecunin; AI; Indus Biotech, India). Participants ingested the assigned capsules once per day in the morning on non-training days and before their workout on training days for 8 weeks.
Significant Group × Time interaction effects occurred over the 8-wk period for percent body fat (AI: -1.77% ± 1.52%, PL: -0.55% ± 1.72%; p = .048), total testosterone (AI: 0.97 ± 2.67 ng/ml, PL: -2.10 ± 3.75 ng/ml; p = .018), and bioavailable testosterone (AI: 1.32 ± 3.45 ng/ml, PL: -1.69 ± 3.94 ng/ml; p = .049).
Significant main effects for time (p ≤ .05) were noted for bench- and leg-press 1RM, lean body mass, and estradiol. No significant changes were detected among groups for Wingate peak or mean power, total body weight, dihydrotestosterone, hemodynamic variables, or clinical safety data (p > .05).
The AI group underwent average increases of 6.57% and 12.26% for total testosterone and bioavailable testosterone, respectively (p < .05). Moreover, we did not see a decrease in serum estradiol and DHT levels, as would be expected from the AI; instead we observed non-significant increases (p > .05) of 26.62% and 6.10%, respectively.
The authors concluded that 500 mg of daily AI supplementation significantly affected percent body fat, total testosterone, and bioavailable testosterone compared with a placebo in a double-blind fashion. (Wilborn et al., 2010)

Dr. Ron


 

Articles

Effects of a purported aromatase and 5α-reductase inhibitor on hormone profiles in college-age men.
(Wilborn et al., 2010) Download
The purpose of this study was to determine the effects of an alleged aromatase and 5-α reductase inhibitor (AI) on strength, body composition, and hormonal profiles in resistance-trained men. Thirty resistance-trained men were randomly assigned in a double-blind manner to ingest 500 mg of either a placebo (PL) or AI once per day for 8 wk. Participants participated in a 4-d/wk resistance-training program for 8 wk. At Weeks 0, 4, and 8, body composition, 1-repetition-maximum (1RM) bench press and leg press, muscle endurance, anaerobic power, and hormonal profiles were assessed. Statistical analyses used a 2-way ANOVA with repeated measures for all criterion variables (p ≤ .05). Significant Group × Time interaction effects occurred over the 8-wk period for percent body fat (AI: -1.77% ± 1.52%, PL: -0.55% ± 1.72%; p = .048), total testosterone (AI: 0.97 ± 2.67 ng/ml, PL: -2.10 ± 3.75 ng/ml; p = .018), and bioavailable testosterone (AI: 1.32 ± 3.45 ng/ml, PL: -1.69 ± 3.94 ng/ml; p = .049). Significant main effects for time (p ≤ .05) were noted for bench- and leg-press 1RM, lean body mass, and estradiol. No significant changes were detected among groups for Wingate peak or mean power, total body weight, dihydrotestosterone, hemodynamic variables, or clinical safety data (p > .05). The authors concluded that 500 mg of dailyAI supplementation significantly affected percent body fat, total testosterone, and bioavailable testosterone compared with a placebo in a double-blind fashion.

 

References

Wilborn, C, et al. (2010), ‘Effects of a purported aromatase and 5α-reductase inhibitor on hormone profiles in college-age men.’, Int J Sport Nutr Exerc Metab, 20 (6), 457-65. PubMed: 21116018