Answer isn't clear, but research suggests supplements, and certain fish, might reduce effect of chemotherapy
WebMD News from HealthDay
By Steven Reinberg
HealthDay Reporter
THURSDAY, April 2, 2015 (HealthDay News) -- Fish oil supplements, and even certain fish, may hinder the effectiveness of cancer-fighting chemotherapy, a new study suggests.
Dutch researchers found herring, mackerel and three other fish oils increased blood levels of the fatty acid called 16:4(n-3) in cancer patients. Experiments in mice have suggested this fatty acid makes cancer cells resistant to chemotherapy, the researchers said. But, it's not certain that what was found to happen in mice would happen with human cancer patients.
Experts noted that research on whether fish oil hurts or helps cancer patients has produced mixed results.
"Dietary supplements are not necessarily benign," said Dwight Kloth, director of pharmacy at Fox Chase Cancer Center in Philadelphia, who had no role in the new study. "There are numerous cases in the literature where nutritional supplements and herbal drugs have had deleterious interactions with chemotherapy."
Many patients begin taking supplements after they receive a cancer diagnosis, but concern is growing that supplements might interfere with anti-cancer treatments, according to background information with the study.
Christine Metz, director of the Laboratory of Medicinal Biochemistry at the Feinstein Institute for Medical Research in Manhasset, N.Y., is among those with concerns.
"Our research shows that when you affect the membrane of cancer cells by altering the fats in the outer covering of the cell, you can make the membrane stiffer or more fluid," she explained.
"These fats can make it more difficult for chemotherapy to enter the cell or make the cell better at pushing the chemotherapy out of the cell," added Metz, who wasn't involved in the study.
The study authors and other experts said the new report, published online April 2 in the journal JAMA Oncology, doesn't prove that fish oil blunts chemotherapy's effects in humans.
And no clinical trial could be done to test the theory. The reason: it would be unethical to evaluate chemotherapy's effectiveness by giving some patients fish oil that could inactivate the drug treatment, said Dr. Len Lichtenfeld, deputy chief medical officer at the American Cancer Society.
source : Could Fish Oil Interfere With Chemotherapy?
