For Patients & Caregivers
How It Works
Broccoli sprouts contain compounds that have anticancer effects. Further studies are warranted.
Broccoli sprouts are young broccoli plants. Lab studies show they contain compounds that have anticancer activities. Small studies suggest that broccoli sprouts can help eliminate environmental toxins and protect against some viruses and bacterial infections. However, more research is needed to confirm these effects.
Studies done in the lab and in animals show that broccoli sprouts contain sulforaphane, which has anticancer properties. In a study conducted in humans, broccoli sprouts were found to play a role in eliminating toxic pollutants. Large-scale studies are needed to confirm such effects.
Broccoli sprouts appear to have anticancer effects in the lab. Studies are being conducted to see whether there may also be some benefit in humans.
Small studies in humans suggest that broccoli sprouts may help reduce inflammation of the stomach caused by the bacterium Helicobacter pylori.
For Healthcare Professionals
Broccoli sprouts are young broccoli plants that have high amounts of glucoraphanin, a precursor of sulforaphane. Sulforaphane is a sulfur-rich compound known to benefit human health.
Few studies have evaluated the effects of broccoli sprouts. Consumption was found to help reduce Helicobacter pylori-induced gastritis (6) (7), but sulforaphane combined with standard triple therapy (proton pump inhibitor, clarithromycin, and amoxicillin) neither improved the eradication rate nor reduced the occurrence of adverse events (20). Intake of sprouts also protected against oxidative stress-induced upper airway disease (8), DNA damage (9); and long-term consumption reduced levels of inflammatory markers in overweight subjects (18). Other preliminary findings suggest supplementation with sprouts may enhance antiviral responses (14); and that glucoraphanin (10) as well as a broccoli sprout beverage (21) aid the excretion of environmental pollutants.
Broccoli sprouts have also been investigated for their potential anti-cancer properties. Sulforaphane demonstrated anticancer effects against prostate (1), breast (2) (3) (16), and urinary cancers (4) in preclinical studies, and may also protect the skin from ultraviolet radiation (5). In murine models, a prenatal/maternal broccoli sprouts diet appeared to offer greater preventive effects on breast cancer development (22) compared with postnatal early-life treatment (17).
In a feasibility trial involving advanced pancreatic cancer patients, although some positive effects were noted, broccoli sprout capsule intake was difficult for some and may have increased digestive symptoms (19). A broccoli sprout extract was found to affect changes in gene expression, but not prostate cancer biomarkers, in men undergoing prostate biopsy (23). In patients with prior melanoma, a broccoli sprout extract was determined to be well tolerated (15), but larger studies that evaluate its chemopreventive potential are needed.
Mechanism of Action
Sulforaphane has been shown to block the initiation stage in carcinogenesis by inhibiting enzymes that convert procarcinogens to carcinogens, and inducing phase 2 enzymes that metabolize carcinogens to facilitate excretion. Induction of phase 2 enzymes occurs through antioxidant response element-driven gene expression, with targets including NAD(P)H:quinone reductase, heme oxygenase 1, and gamma-glutamylcysteine synthetase regulated by nuclear factor E2 related factor (13). Sulforaphane also suppresses cancer development through various molecular targets. It induces G2/M cell cycle arrest via cyclin-dependent kinases and triggers dose-dependent apoptosis and inhibits histone deacetylase by its metabolites in vitro (13). In a triple-negative breast cancer animal model, sulforaphane protection against cancer stem-like cell proliferation was attributed to suppression of the Cripto-mediated pathway and/or the Cripto/Alk4 protein complex (16).
In a small human study, broccoli sprout homogenates enhanced antiviral defense responses via peripheral blood NK cell activation and increased granzyme B production (14).
A meta-analyses showed that consumption of cruciferous vegetables has a significant effect on CYP1A2 and glutathione S-transferase-alpha (GST-α), increasing the activities of these enzymes by 20-40% and 15-35%, respectively (24). It is not known if broccoli sprouts would have similar effects.