Originally published 9/21/2020
Since we posted this blog, more research on the properties of sulforaphane as a natural anti-tumor agent has been published. Technical terms like tumorigenicity (the gene-driven development of tumors) and antineoplastic (the property of discouraging new abnormal cells) are big words but their meaning is simple. Sulforaphane has potent cancer-prevention activities, as described by Elkashty, et al. (2021).[i] Their paper was published a year after we posted the blog below, and it identifies three mechanisms by which is discourages the development of prostate cancer and other cancers: 1) it puts the brakes on cancer cells’ ability to metabolize needed enzymes; 2) it inhibits the cells from proliferating and induces cancer cell death; and 3) it interferes with the tumor’s ability to develop its own blood supply and spread. It may play a role in boosting favorable outcomes of chemotherapy for patients with metastatic disease. As we note in the earlier blog, you’d have to eat a lot of cooked broccoli to gain a significant benefit, but if you’re interested, talk to your doctor or a registered dietician about the merits of supplements formulated to deliver a sulforaphane powerhouse.
“I’m President of the United States, and I’m not going to eat any more broccoli!” When George W. H. Bush made this declaration in 1990, he became known as the man who hated broccoli. He’s not alone. Many people don’t care for broccoli, a member of the cruciferous vegetable family. Broccoli and its cousins (e.g. Brussels sprouts, cauliflower, cabbage, etc.) contain sulfur, a mineral that supports many essential background programs that keep our bodies in optimum health. Sulfur also lends a bitter taste and sulfurous odor that is off-putting for a lot of people, from presidents to parking lot attendants.
That’s too bad, because cruciferous vegetables have powerful organosulfur compounds called glucosinolates that benefit our bodies enormously. When glucosinolates interact chemically with water, they produce isothiocyanates, one of which is sulforaphane, abundant in broccoli and broccoli sprouts.
Sulforaphane is of scientific interest because of “… its therapeutic and biological activities such as antidiabetic, antioxidant, anti-inflammatory, hepatoprotection [liver], and cardiprotection [heart].”[ii] Its antioxidant and anti-inflammatory properties keep organs and glands healthy, thus supporting a well-functioning prostate gland. In addition, sulforaphane may reduce prostate cancer (PCa) risk.
Sulforaphane and prostate cancer
To understand the biological antitumor activity of sulforaphane, we have to get up close and personal with molecules in the body called microRNAs (miRNA). Among other things, miRNAs are like written instructions for cell behavior because they play a powerful role in regulating gene expression (switching genes on or off). Individual miRNAs can, in some instances, downregulate hundreds of target genes. When miRNAs don’t function properly, genes become dysregulated—a hallmark of cancer cells.
Sulforaphane helps keep miRNAs in tiptop shape. Thus, through miRNAs, sulforaphane exercises “…great antitumor activity and is able to significantly inhibit proliferation, viability, migration, malignancy, and epithelial-to-mesenchymal transition of cancer cells.”[iii] Laboratory research has shown that broccoli-related supplements have a chemosuppressive effect against colon and skin cancer cells so it was logical to test it on prostate cancer. A 2012 published review and summary of over a dozen previous papers observed a link between eating cruciferous vegetables and a decreased risk of PCa.[iv]
Studies confirm sulforaphane effect
To analyze the chemopreventive action of sulforaphane against PCa, a 2018 study by Beaver, et al.[v] tested it on laboratory mice that were genetically modified to develop (at about 12 weeks of age) a progressive form of PCa that metastasizes. The mice were divided into two dietary groups, either a diet high in broccoli sprout powder or a control diet without the powder. Tissue samples from mouse organs, including prostates, were collected at 12 and 28 weeks of age in order to diagnose the extent of PCa and to perform genomic analysis of their cancerous and noncancerous organ tissues. The mice fed the broccoli sprout diet had less PCa incidence, reduced extent of metastasis at 12 weeks (though this became more comparable to controls by 28 weeks), and more favorable expression of genes that deter PCa cells. The researchers attribute these properties to the sulforaphane in the broccoli sprouts.
Even more compelling, Cipolla, et al. (2015) conducted a “…double-blinded, randomized, placebo-controlled multicenter trial with sulforaphane in 78 patients (mean age, 69 ± 6 years) with increasing PSA levels after radical prostatectomy.”[vi] The treatment group took a daily oral preparation of 60 mg of stabilized free sulforaphane while the control group took a placebo. The authors reported that over a 6-month period, mean changes in PSA levels were “significantly lower” for the sulforaphane group; PSA doubling time was 86% longer in this group; and PSA increases greater than 20% were “significantly greater” in the placebo group. They note that compliance and tolerance were very good.
Thus, both the mouse study and the post-prostatectomy showed that as an intervention, sulforaphane delivered a blow to higher-risk, established PCa. Indirectly, this connects well with the literature review showing decreased PCa risk (prevention) associated with eating cruciferous vegetables in general.
Sounds great, bring on the broccoli!
If you’re thinking, “Wow, I’m going to start eating broccoli at every meal,” slow down. First, sulforaphane in its pure or “free” form must be converted from its glucosinolate precursor through processing (cutting, chopping, chewing). Bio-availability occurs due to either enzyme action released during processing, or contact with gut microbes once you’ve swallowed your cruciferous veggies. You’d have to eat a lot of broccoli to achieve a meaningful concentration of sulforaphane!
However, if you look back to the post-prostatectomy study, patients were given an oral preparation of stabilized free sulforaphane. In other words, you can buy sulforaphane as a nutraceutical. However, “let the buyer beware.” There are plenty of companies out there promoting their product as the best, purest, one and only, etc. UVital’s website explains the benefits of this natural compound, and lists several preparations that they deem consume-worthy. According to uVital, the first 3 on their list are reputable brands that “…are also used by Johns Hopkins University in their clinical studies.”[vi]
I am not recommending for or against use of stabilized free sulforaphane, only that you discuss with your own doctor the pros and cons. That said, I always recommend plenty of fresh fruits and veggies—especially cruciferous if your taste buds don’t object—as part of a healthy diet. Be well!
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[i] Elkashty OA, Tran SD. Sulforaphane as a Promising Natural Molecule for Cancer Prevention and Treatment. Curr Med Sci. 2021 Apr;41(2):250-269.
[ii] Rafiei H, Ashrafizadeh M, Ahmadi Z. MicroRNAs as novel targets of sulforaphane in cancer therapy: The beginning of a new tale? Phytother Res. 2020 Apr;34(4):721-728.
[iv] Liu B, Mao Q, Cao M, Xie L. Cruciferous vegetables intake and risk of prostate cancer: a meta-analysis. Int J Urol 2012;19:134–41.
[v] Beaver LM, L?hr CV, Clarke JD, Glasser ST et al. Broccoli Sprouts Delay Prostate Cancer Formation and Decrease Prostate Cancer Severity with a Concurrent Decrease in HDAC3 Protein Expression in Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) Mice. Curr Dev Nutr. 2018 Mar; 2(3): nzy002.
[vi] Cipolla B, Mandron E, Lefort JM, Coadou Y et al. Effect of sulforaphane in men with biochemical recurrence after radical prostatectomy. Cancer Prevention Research. 2015;8(8):712-719. DOI: 10.1158/1940-6207.CAPR-14-0459.
[vii] uVitals website, https://uvitals.com/sulforaphane-supplements/