Preclinical experiments reported recently in the journal Cancer Cell suggest fish oil may reduce the effectiveness of chemotherapy, however, the Global Organization for EPA and DHA Omega-3s (GOED), Salt Lake City, UT, said application of these results should depend on future research.

“The results can and should be used to design additional studies either to further the development of new chemotherapeutic agents and/or to identify strategies to enhance current chemotherapy effectiveness by decreasing drug resistance,” the group said in a statement.

GOED explained that the PIFA, 16:4(n-3), is present in commercially available fish oil products and individuals with cancer, who like the rest of the population are frequent users of such products.

For this research, investigators fed tumor-bearing mice either purified PIFAs or commercially available fish oil products and treated them with the chemotherapeutic agent cisplatin. PIFAs induced resistance to cisplatin. In addition, at doses similar to those taken by humans, commercially available fish oil products resulted in neutralization of the antitumor effects of cisplatin. According to the authors, the results provide support for the clinical relevance of this fatty acid in the development of resistance to chemotherapy. 


According to GOED, “During this calendar year alone, there have been three publications reporting on research about the long-chain omega 3 fatty acids increasing chemotherapy efficacy. While the results are exciting, they, like the results from the controversial publication, are just pieces of the puzzle, not a basis for making any recommendations. For the positive body of evidence, further research is warranted to identify specific mechanisms by which long-chain O-3s increase chemotherapy efficacy and to determine the optimal cellular/membrane levels of long-chain O-3s required to promote these mechanisms, such that these fatty acids may be prescribed as adjuvants to chemotherapy.”