The effect of lycopene supplement from different sources on prostate specific antigen (PSA): A systematic review and meta-analysis of randomized controlled trials.

Systematic review and meta-analysis of randomized controlled trials in men. Included populations were men with prostate cancer, men at increased risk for prostate cancer or with high-grade prostatic intraepithelial neoplasia, men with benign prostatic hyperplasia, and healthy men; the meta-analysis pooled 6 studies with total N=298 out of 9 studies in the review.

Randomized trials evaluated lycopene delivered as tomato-derived products or purified/synthetic lycopene, compared with control/placebo. Doses ranged from 8 mg/day to 45 mg/day, most commonly 15 to 30 mg/day, with durations from 3 weeks to 48 weeks; one crossover trial used tomato paste 200 g/day in phase 1 and purified lycopene 16 mg/day in phase 2. One active arm also included a multivitamin with lycopene.

Lycopene supplementation did not significantly reduce PSA compared with control, and the null effect was consistent across subgroups. Across the included trials, PSA responses were mixed, with some studies reporting reductions, others increases, and one reporting no difference in PSA change. The meta-analysis included 6 studies and 298 participants, but the authors concluded that the overall evidence does not support a meaningful PSA-lowering effect. They recommended larger, more consistent randomized trials to clarify whether any true benefit exists.

The evidence base was small, with only 6 studies contributing to the meta-analysis and substantial heterogeneity across sources, doses, durations, and patient populations. Several trials did not provide clearly extractable PSA numerical data, and one crossover study limited comparability. Generalizability is also constrained by the mixture of clinical groups, including prostate cancer, high-risk, BPH, and healthy men.