Fatty fish incorporate the marine omega-3 fats docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Fatty fish consumption has been shown to be associated with reduced risk of breast cancer and improved survival. Marine fatty acids have also been found to enhance the therapeutic effects of chemotherapy drugs such as Adriamycin and Taxol. Now a new study has reported that DHA improves the effectiveness of Adriamycin in triple negative breast cancer cells.

Fish oil supplements not recommended during chemotherapy

While consumption of fatty fish and other sources of omega-3 fats may be beneficial during chemotherapy, fish oil supplements could be harmful. A study published in 2011 reported that the fatty acids 12-oxo-5,8,10-heptadecatrienoic acid and hexadeca-4,7,10,13-tetraenoic acid in some fish oil supplements induce resistance to chemotherapy drugs. Unfortunately, consumers are not in a position to know which fish oil supplements incorporate these two unwanted fatty acids.

In addition, there is some evidence that fish oil supplements taken during Adriamycin chemotherapy do not prevent heart damage and might actually promote it. Adriamycin and other anthracycline chemotherapy can cause cardiomyopathy, damage to the heart muscle that weakens its ability to pump and can lead to heart failure. Contrary to expectations, fish oil supplements might actually increase the risk of Adriamycin-induced chemotherapy. In one study, sheep given fish oil displayed more signs of anthracycline cardiotoxicity than control sheep.

Research finds DHA enhances Adriamycin effectiveness in triple negative cells

The study referenced at the beginning of this news article was designed to investigate the effects of DHA and EPA on three types of breast cancer cells. Triple negative MDA-MB-231, hormone receptor positive MCF-7, and HER2 positive SKBr-3 cells were incubated with EPA or DHA and with or without Adriamycin (doxorubicin) or Herceptin.

Both DHA and EPA were found to inhibit the growth of all three breast cancer cell lines in a dose-dependent manner. On the other hand, neither DHA nor EPA altered the growth or metabolic activity of normal breast cells. Pre-treatment with DHA, but not EPA, improved the efficacy of Adriamycin in triple negative cells, but not the other cell lines. The authors conclude that treatment of triple negative breast cancer cells with DHA increases the anti-cancer effects of Adriamycin.

Please see our article on breast cancer diet during Adriamycin chemotherapy for more information on how to optimize such treatment.