Horseradish is recommended for breast cancer in moderation
Like broccoli, cabbage, and kale, horseradish (Armoracia rusticana) is a brassica vegetable. Components of horseradish have been shown to have anti-hypercholesterolemic, antimutagenic, and both antioxidant and pro-oxidant effects. Horseradish and wasabi (Japanese horseradish) have been reported to have anti-cancer effects due to the glucosinolate sinigrin and various isothiocyanates such as sulforaphane, phenethyl isothiocyanate, allylisothiocyanate, 7-methylsulfinylheptyl isothiocyanate, and 6-methylsulfinylhexyl isothiocyanate. Horseradish also contains flavonoids such as kaempferol. Horseradish has been shown to inhibit the growth of food poisoning bacteria and fungi. Raw cruciferous vegetables have been shown to reduce the risk of bladder cancer. Horseradish and wasabi have been shown to inhibit the proliferation of colon, lung, pancreatic, prostate and stomach cancer cells.
Breast cancer-related effects of eating horseradish
Sulforaphane, a component of horseradish, has been found to inhibit the proliferation of human breast cancer cells. Oral administration of either sulforaphane, or its glucosinolate precursor, glucoraphanin, has been shown to inhibit carcinogen-induced mammary carcinogenesis in rats. A small study of healthy women undergoing breast reduction found that sulforaphane metabolites were readily measurable in the breast tissue removed during surgery after ingesting a single dose of a brassica vegetable preparation containing 200 µmol of sulforaphane, indicating that the substance is bioavailable after consumption. Sulforaphane has been shown to arrest proliferation and mitosis of breast cancer cells in a manner weaker than, but similar to, antimitotic chemotherapy drugs such as the taxanes Taxol and docetaxel. While one carefully designed study of Chinese women found that brassica vegetable consumption was associated with significantly reduced breast cancer risk, population studies specifically evaluating the impact of consuming horseradish or wasabi are not available.
Additional comments
Uncooked horseradish root typically is used in making horseradish sauce (the root can also be used simply grated). This preserves much of its anti-cancer properties, since cooking can substantially reduce or destroy isothiocyanates.
Horseradish and wasabi can interfere with Warfarin (coumadin) and other blood-thinning therapy. Horseradish and wasabi are both toxic at high doses.