Dr. Rhonda Patrick on broccoli sprouts: what the evidence says · JRE #1178
SUBJECT: BROCCOLI SPROUTS
Not a true/false call. Every claim is logged with its sources; read the exhibits below.
So, you know, there's intervention trials in humans that it's, you know, men that were given broccoli sprout extract lowered their biomarker for prostate cancer by like 86% or lowered the doubling rate of it by 86%.
What the evidence says 01 / RECORD
Patrick appears to be referencing Cipolla et al. (2015), a double-blind, randomized, placebo-controlled trial of 78 men with rising PSA after radical prostatectomy who received 60 mg/day of stabilized sulforaphane or placebo for six months. The trial did report that PSA doubling time was 86% longer in the sulforaphane group than placebo (28.9 vs. 15.5 months), so the 86% figure itself is accurate to a real published result. However, PSA doubling time was a secondary outcome; the trial's pre-specified primary endpoint (change in log PSA slope from baseline to month 6) was not met. PSA doubling time is a surrogate biomarker, not a measure of cancer recurrence, metastasis, or survival. A 2023 systematic review of randomized controlled trials on sulforaphane in cancer found that results on PSA-related outcomes across the small number of available prostate cancer trials were inconsistent, that 75% of included trials carried a high risk of bias, and concluded that large-scale, robust trials are needed before clinical recommendations can be made. A separate small single-arm phase II trial of a different sulforaphane-rich extract (20 patients) found a smaller, though still statistically significant, lengthening of PSA doubling time (6.1 to 9.6 months).