Sulforaphane (Broccoli Sprout Extract)

Bahadoran et al. (Int J Food Sci Nutr, 2012; PMID 22537070): 81 patients with type 2 diabetes in Tehran, 10 or 5 g/day broccoli sprout powder or placebo for 4 weeks; serum insulin and HOMA-IR fell at 10 g/day. The same trial was reported twice more: Bahadoran et al. (Eur J Clin Nutr, 2011; PMID 21559038) on oxidative stress markers and Bahadoran et al. (Diabetes Res Clin Pract, 2012; PMID 22325157) on triglycerides and oxidized LDL. Three papers, one 81-patient trial; they do not replicate each other. Axelsson et al. (Sci Transl Med, 2017; PMID 28615356): a concentrated broccoli sprout extract reduced fasting glucose and HbA1c in obese patients with dysregulated type 2 diabetes, which the abstract states as the group in which the effect appeared, so it is a subgroup result. Dwibedi et al. (Nat Microbiol, 2025; PMID 39929977): the same Lund group, 74 drug-naive adults with prediabetes, 12 weeks; the prespecified primary endpoint (a 0.3 mmol/L fall in fasting glucose) was missed, with an overall fall of 0.2 mmol/L; two authors hold patents on sulforaphane for hepatic glucose production licensed to a company in which one holds stock, and the extract's manufacturer supplied the product and placebo. NULL FINDINGS on the mechanism: Wise et al. (PLoS One, 2016; PMID 27832073), 89 patients with COPD, 4 weeks, no effect on Nrf2 target gene expression; Ribeiro et al. (J Ren Nutr, 2024; PMID 37619675), 30 hemodialysis patients, crossover, no change in NRF2 or NF-kB mRNA; Ribeiro et al. (Free Radic Biol Med, 2024; PMID 38772511), non-dialysis chronic kidney disease, NRF2 and NQO1 mRNA rose at 400 micrograms/day for one month, the one positive. Christiansen et al. (PLoS One, 2010; PMID 20805984): 40 adults with hypertension, 10 g/day dried broccoli sprouts for 4 weeks; no improvement in flow-mediated dilation or blood pressure. Singh et al. (Proc Natl Acad Sci U S A, 2014; PMID 25313065): randomized placebo-controlled trial in autism spectrum disorder, a different population and question, not graded here. Egner et al. (Cancer Prev Res (Phila), 2011; PMID 21372038): bioavailability crossover of two sprout beverages in Qidong, China; grades nothing. Grade C: small, short, partly subgroup-driven and inconsistent surrogate results.