Broccoli Sprouts Help Fight Cancer
There are no conclusive clinical trials evaluating the effects of broccoli sprouts on cancer.
Reports on The TruthAboutCancer.com and DrJockers.com advocate growing broccoli sprouts in order to prevent or treat cancer. Cruciferous vegetables (Brassicaceae) such as broccoli sprouts are enriched with several chemical components, such as sulforaphane (SFN) and indole-3-carbinol (I3C) which are known to have prevent the proliferation of cancer cells.
The article in TheTruthaboutCancer.com had no references to support the claim about the cancer protective effects of broccoli sprouts. The main clinical study quoted in DrJockers.com is a German pilot study which began in 2014 (1). The aim of the study was to evaluate the effect of broccoli sprouts on advanced pancreatic cancer. The results of the study have not yet been published. The paper quoted by DrJockers.com is essentially just a summary of the study design but does not contain any results.
There is a clinical trial looking at broccoli sprouts in the context of cancer which is an intervention trial done in China (2). The study recruited two hundred and ninety-one study participants from the rural He-He Township, Qidong, in the Yangtze River delta region of China (an area characterized by high levels of airborne pollutants). Study participants were randomized to receive a broccoli sprout-derived beverage providing daily doses of 600 μmol glucoraphanin and 40 μmol sulforaphane for a period of twelve weeks.
There were statistically higher levels of urinary excretion of metabolites of pollutants in the group taking the broccoli sprout drink as compared to the controls. The authors concluded that the broccoli drink increased levels of detoxification of air borne pollutants. The study was not powered to evaluate the downstream effects of this increase in detoxification of air borne pollutants to see if this translated into any clinical benefit for the patients.
Another double blind, randomized, placebo-controlled trial was conducted in 22 men with recurrent prostate cancer (3). Patients were randomized to either an active treatment arm or placebo for 12 weeks. The treatment arm consisted of a phytotherapeutic intervention containing turmeric, resveratrol, green tea and broccoli sprouts. Adherence to study protocol was excellent, and the phytotherapeutic intervention was well-tolerated. No statistical difference in clinical outcomes was observed between the treatment or placebo arm of the study.
A comprehensive study evaluated the safety profile of broccoli sprout extracts. The placebo controlled study involved monitoring clinical and laboratory effects of a seven day course of different doses of broccoli sprout extract and found that the broccoli sprout extract was well tolerated (4).
In summary, even though it is biologically plausible that broccoli sprouts could be beneficial in the prevention or treatment of cancer, there is no definitive clinical evidence to support this claim at this time (5).
- Pilot study evaluating broccoli sprouts in advanced pancreatic cancer (POUDER trial)- study protocol for a randomized controlled trial. Lozanovski VJ, et al. Trials. 2014;15:204. PMCID: 4059031
- Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in China. Egner PA, Chen JG, Zarth AT, Ng DK, Wang JB, Kensler KH, Jacobson LP, Muñoz A, Johnson JL, Groopman JD, Fahey JW, Talalay P, Zhu J, Chen TY, Qian GS, Carmella SG, Hecht SS, Kensler TW. Cancer Prev Res (Phila). 2014 Aug;7(8):813-23. doi: 10.1158/1940-6207.CAPR-14-0103. Epub 2014 Jun 9
- A Placebo-Controlled Double-Blinded Randomized Pilot Study of Combination Phytotherapy in Biochemically Recurrent Prostate Cancer. van Die MD, Williams SG, Emery J, Bone KM, Taylor JM, Lusk E, Pirotta MV. Prostate. 2017 May;77(7):765-775. doi: 10.1002/pros.23317. Epub 2017 Feb 9.
- Safety, tolerance, and metabolism of broccoli sprout glucosinolates and isothiocyanates: a clinical phase I study. Shapiro TA, Fahey JW, Dinkova-Kostova AT, Holtzclaw WD, Stephenson KK, Wade KL, Ye L, Talalay P. Nutr Cancer. 2006;55(1):53-62.
- The Epigenetic Impact of Cruciferous Vegetables on Cancer Prevention. Royston KJ, Tollefsbol TO. Curr Pharmacol Rep. 2015 Feb 1;1(1):46-51.