Fish Oil Supplements Might Negate Chemotherapy And Should Be Avoided During Treatment, Study Claims

Cancer patients taking fish oil supplements might risk becoming resistant to chemotherapy while attempting to improve their health, researchers say. According to the new study, once someone has been diagnosed with cancer, food supplement-use statistically increased three-fold.

About one-in-five cancer patients take supplements with omega-3 fatty acids, according to the researchers involved in the study published in the medical journal JAMA Oncology, which also stated that most of the omega-3 supplements these patients take is in the form of fish oil supplements. According to the researchers, getting increased fatty acid by using certain fish oil supplements might actually negate chemotherapy effects and be dangerous to patients’ health.

The American Cancer Society has an informational page about the use of fish oil supplements and other omega-3 fatty acids. It states that there is mixed evidence of its health benefits relating to cancer and tumor growth, and explained that in the past, a researcher claimed to have treated cancer by using fish oil.

“In the 1950s, a German scientist named Johanna Budwig, PhD, discovered essential fatty acids and developed a diet that she said would fight cancer. Dr. Budwig claimed that many of her patients experienced tumor reduction within 3 months, and she stated that some experienced even more dramatic results. Dr. Budwig has reportedly used omega-3 fatty acids in combination with other nutrients to treat thousands of people with cancer and other diseases.”

The American Cancer Society also stated that it is not known what kind of medications that fish oil supplements might adversely affect. The new research indicates that chemotherapy medication is most likely adversely affected by the use of fish oil supplementation.

Dr. Emilie E. Voest, of the Netherlands Cancer Institute in Amsterdam, and her fellow researchers authoring the new study say that fish oil supplements contain “substantial levels of 16:4(n-3), a fatty acid with potent chemotherapy-negating effects in preclinical models, and that intake of low doses of fish oil interferes with chemotherapy activity in mice.”

The researchers had already determined that the fatty acid 16:4(n-3) as well as the fatty acid 12S-HHT induced chemotherapy resistance in mice studies, according to Medical News Today. The researchers wrote that the combination of the chemotherapy drug “with as little as 2.5 pmol of orally administered 16:4(n-3) induced virtually complete chemoresistance.”

The researchers examined commonly used omega-3 supplements and found 16:4(n-3) was in all of the fish oil supplements they tested. Similarly, when healthy volunteers ate fresh mackerel and herring, the effect was the same as what the researchers found with the fish oil supplements. Salmon had similar effects, but to a much lesser extent.

“Herein we show that fish oil contains substantial levels of 16:4(n-3), a fatty acid with potent chemotherapy-negating effects in preclinical models, and that intake of low doses of fish oil interferes with chemotherapy activity in mice.”

The researchers suggested that people should avoid taking fish oil supplements and eating herring and mackerel during the window of time spanning from the day before their chemotherapy treatment until the day after their treatment. The researchers said that this 48-hour window without the consumption of fish oil supplements, mackerel, and herring should be sufficient to avoid risking chemotherapy resistance.

[Photo via Pixabay]