Saturday June 8, 2013 (foodconsumer.org) -- Resveratrol, a compound found in red wine and red grapes, has been found protective against cardiovascular disease and cancer in many studies.   But a new study in BMC Complementary & Alternative Medicine suggests that breast cancer patients may be better off not taking resveratrol as a dietary supplement.

Linette Castillo-Pichardo and colleagues from University of Puerto Rico in San Juan, Puerto Rico conducted the study and found exposure to low concentrations of resveratrol promoted mammary tumor growth and metastasis in cancer cell lines.

The researchers earlier demonstrated that resveratrol regulates the activity of the migration/invasion regulator Rac in vitro.  In the current study, resveratrol treated mice were found to have a high tumoral Rac activity and increased levels of other tumor promoting molecules. 

The researchers concluded that low concentrations of resveratrol may potentially promote breast cancer growth and metastasis.

Another study published in the International Journal of Cancer suggests that taking organic selenium such as methylseleninic acid or selenomethionine may help prevent or slow metastasis of breast cancer.

The study led by Y.C. Chen and colleagues from The Pennsylvania State University in University Park, PA shows that mice inoculated with 4T1.2 cells and then fed three diets supplemented with either sodium selenite (an inorganic selenium chemical), methylseleninic acid or selenomethionine all had delayed tumor growth.

The researchers found the inorgnaic selenite supplementation only provided a short term delay of the tumor growth whereas the two organic selenium compounds provided more significant cancer growth inhibition.

These diets were also found to have an impact on metastasis.  Mice fed selenite developed more severe metastasis and suffered higher incidence of kidney and bone metastasis while mice fed selenomethionine had the most reduced cancer growth at metastatic sites.  Methylseleninic acid provided some protection against breast cancer metastasis, but it was not as effective as selenomethionine.

The researchers concluded "Our data suggest that organic Se supplementation may reduce/delay breast cancer metastasis while selenite may exacerbate it."  (reporting by Jimmy Downs)