Key Takeaway
In premenopausal women, 75 mg/day DIM for 30 days did not significantly increase the estrogen metabolite urine ratio, but did significantly reduce body fat percentage compared to placebo.
Summary
This randomized, double-blind clinical trial (NCT02525159) investigated whether DIM supplementation could improve estrogen metabolism and body composition in premenopausal women with suboptimal estrogen metabolite profiles.
Sixty premenopausal women with an Estrogen Metabolites Urine Ratio (EMUR) below 0.9 were randomized to receive either 75 mg daily DIM (administered as 300 mg DIM-BR) or placebo for 30 days, with follow-up 30 days after supplementation ended. Urine samples were collected at baseline, day 30, and 30 days post-supplementation.
The primary outcome, EMUR, did not significantly increase during the 30-day supplementation period. However, there was a non-significant positive trend 30 days after supplementation ended (p = 0.06), suggesting a possible delayed effect. For body composition, the DIM group showed a statistically significant decrease in body fat percentage compared to placebo (p = 0.04).
The researchers concluded that 75 mg daily DIM was ineffective at the studied dose and timeframe for increasing EMUR, and that further studies are needed to evaluate effective dosage, longer treatment durations, and the mechanism behind the body fat reduction. The dose used (75 mg) was notably lower than the 200-300 mg typically used in other DIM studies, which may explain the modest estrogen metabolism results.