Sulforaphane is a naturally occurring isothiocyanate found in cruciferous vegetables, particularly broccoli sprouts. Its use to support breast health is primarily justified by scientific research rather than traditional medicine. Multiple preclinical studies have shown that sulforaphane can modulate pathways involved in cancer development, including those relevant to breast tissue. In vitro and animal studies suggest that sulforaphane induces phase II detoxification enzymes, promotes apoptosis, inhibits histone deacetylase, and can impede the proliferation of breast cancer cells. Some observational and interventional studies in humans indicate that higher intake of cruciferous vegetables is associated with a reduced risk of breast cancer, although the evidence is not conclusive and is often confounded by other dietary factors.

Recent pilot clinical trials have investigated sulforaphane supplementation in women with atypical breast cells or at high risk for breast cancer, showing favorable modulation of biomarkers linked to cancer risk, but these studies are small and preliminary. There is not yet robust evidence from large, long-term randomized controlled trials demonstrating that sulforaphane supplementation definitively prevents breast cancer or improves breast health outcomes in humans. Thus, the scientific evidence is promising but still emerging, justifying a moderate evidence rating.