The present study was done of extracts of freeze-dried cabbage (FDC), freeze-dried fermented cabbage (FDS) and acidified Brussels sprouts (ABS), all of which are classified as cruciferous vegetables. The authors tested these products for their estrogenic and anti-estrogenic effects and for their ability to bind the estrogen receptors on cell walls.
The extracts did bind to the estrogen receptors with low affinity. They bound with decreasing affinity in the following order: estradiol, FDS, FDC, ABS. The same extracts were tested for their estrogenic and anti-estrogenic effects in estrogen-dependent breast cancer cells. All extracts at a concentration of 5-25 ng/ml reduced the growth and spread of cancer cells. At concentrations from 50 ng/mL to 24 mcg/mL all extracts increased proliferation of cancer cells. The extracts and estradiol did not work against estrogen resistant cancer cells.
Epidemiologic studies have shown that consumption of cruciferous vegetables helps prevent several kinds of cancers. Cruciferous vegetables contain a chemical called indole-3-carbinol (I3C). In acidic conditions, I3C is converted to 3, 3′-diindolylmethane (DIM) and indolocarbazole (ICZ), which are more potent estrogen receptor activists.
CONCLUSION: This study shows that cruciferous vegetable extracts are anti-estrogens at low concentrations and estrogen agonists at high concentrations. This alters the proliferation of breast cancer cells. Freeze-dried fermented cabbage seemed to be the most active. At higher doses, some of these chemicals can stimulate estrogen dependent proliferation. However, the authors believe it would be quite difficult to eat sufficient cruciferous vegetables to obtain such high blood levels.
NOTE: The response of these chemicals at different doses is an example of hormesis, which says that chemicals have different effects on the body’s tissues at different levels of concentration.
Read about the use of DIM from cabbage, brussel’s sprouts and broccoli angiostatic therapy for cancer.