The specialists tested 6 different types of fish oil supplements, and all of them hinted at making chemotherapy less effective. Why? Since as indicated by the report in JAMA Oncology, they contained a particular fatty acid that reduced the effectiveness of chemotherapy when tested on mice.
Lead author of the study, Dr. Emile Voest from the Netherlands Cancer Institute in Amsterdam, said that people experiencing chemotherapy sessions should avoid any kind of fish oil supplements. In addition, any supplements must be discussed with their physicians, as he advised patients to stay honest about their intake of medication.
The most common source of fish oil, containing omega-3 fatty acids come as capsules sold for about $10 or $11 for 100 pills. The researcher’s survey demonstrated that approximately a 5th of Americans with cancer take them.
Voest clarified that the mice experiments demonstrated that even small amounts of such fatty acids radically decreased the chemotherapy’s effectiveness. In fact, they go about as enablers for cancer cells to start repairing themselves a lot faster after every chemotherapy session.
Same researchers surveyed another 400 people undergoing treatment for cancer in November 2011. Just 118 people answered the surveys, 35% of whom said they used nutritional supplements; simultaneously, 11% reported taking omega-3 fatty acid supplements.
Part of the same study, the researchers asked 20 volunteers to eat mackerel or herring, and the results exhibited increasing levels of 16:4(n-3) in their blood. However, salmon or tuna consumption did not have the same effect, but closer to none.
Further research is required for more solid data, but the investigators suggest that all patients experiencing chemotherapy should avoid fish oil – especially a day before and a day after they do the treatments.
Both the Dutch Cancer Society and the Dutch National Working Group for Oncologic Dieticians support this study, agreeing with their conclusions. Dr. Powel Brown, head of the Department of Clinical Cancer Prevention at the University of Texas, said that the results warrant more observations and experiments before making more strongly suggestions.
Despite the fact that Dr. Brown was not involved in the study, he discouraged patients’ use of additional supplements, because they are known to affect the natural course of chemotherapy.
Although Voest conceded their study to have made some circumstantial conclusions, he added that ethics make it hard for researchers to confirm the findings. It is not permitted to randomly give chemotherapy patients fish oil capsules just to see the results.