Fish Oil Fatty Acids Are So Protective, They Resist Chemotherapy

Researchers caution against the use of these fish oils, while undergoing chemo

By Heather Callaghan

A breast cancer survivor once told me that she was ordered to stop drinking green tea while undergoing chemotherapy so that the chemo would have a chance “to take.” The green tea was fighting off the drug’s effects. It turns out, other substances have chemo-thwarting tendencies.

Researchers have noticed that certain compounds make chemotherapy drugs less lethal towards the target. Are these substances “protecting the tumor” or strengthening the body to point it pushes away chemotherapy?

Emile E. Voest, M.D., Ph.D., of the Netherlands Cancer Institute, Amsterdam, and others examined exposure to the fatty acid 16:4(n-3) after eating fish or taking fish oil. Their research was published online by JAMA Oncology.

The authors examined the rate of fish oil use among patients undergoing cancer treatment, while researchers also recruited healthy volunteers to examine blood levels of the fatty acid after ingestion of fish oils and fish. The fish oil portion included 30 healthy volunteers and the fish portion included 20 healthy volunteers.


Among 118 cancer patients who responded to a survey about the use of nutritional supplements, 35 (30 percent) reported regular use and 13 (11 percent) used supplements containing omega-3 fatty acids, according to the results.

The study found increased blood levels of the fatty acid 16:4(n-3) [that’s a shorthand denotation for this particular type of acid] in healthy volunteers after the recommended daily amount of 10 mL of fish oil was administered. An almost complete normalization of blood levels was seen eight hours after the 10-mL fish oil dose was given, while a more prolonged elevation resulted after a 50-mL dose.

Eating 100 grams of herring and mackerel also increased blood levels of 16:4(n-3) compared with tuna, which did not affect blood levels. Salmon only created a small, short-lived peak.

The study concludes:

Taken together, our findings are in line with a growing awareness of the biological activity of various fatty acids and their receptors and raise concern about the simultaneous use of chemotherapy and fish oil. Based on our findings, and until further data become available, we advise patients to temporarily avoid fish oil from the day before chemotherapy until the day thereafter.

If you read the actual study, you find the studied fatty acid was previously found to activate splenic macrophages (leading to resistance to chemotherapy in mouse models.) Powerful enough to neutralize chemo? Stimulate macrophages? That’s incredible!

Macrophages, which literally means “big eaters,” are a type of white blood cell that are crucial to cancer prevention by engulfing junk. They up the immune response, recruit other immune cells, but can also reduce inflammation by releasing cytokines. It sounds like it might compete with chemo for receptor sites too, and that the health-boosting benefits also reduce the efficacy of chemotherapy.

How tragic that what appears to be a phenomenal discovery is shrouded in a caution to avoid during chemo, but understandably so, considering the end goal of chemo. If undergoing allopathic (conventional Western) methods alone or with alternative methods, definitely discuss what you’re doing with your doctor and follow directions because everyone needs to have an understanding. Not doing so could cause harm.

It would be like taking taking mega-doses of probiotics while taking antibiotics in order to be healthy, but not realizing that they have just canceled each other out. Now neither have worked and the person has just taken antibiotics for nothing. The doctor unwittingly thinks the person is on the road to recovery and that the antibiotic has wiped the infectious agents out.

In other words, this article is in no way recommending going against that advice. However, this discovery leads one to ponder if herring and mackerel would make a wonderful preventative food for even more reasons than previously understood.

Modern fish oil isn’t always as advertised and there are multiple, simultaneous fish scandals afoot. While it’s the mackerel and herring that provide the particular fatty acid studied above, people interested in fish oil might want to also look into fermented cod liver oil. If interested in non-fishy Omega-3s to fight inflammation, consider grinding flax seed or my personal favorite – Black Current Seed Oil. Please research it, it’s my go-to for Omega-3s, the nervous system, GLA, hormones, heart, immunity, skin, nails and connective tissues.

The information on this article comes from a medical study, but is not intended to replace your relationship with a qualified health care professional and is not intended as medical advice.

Heather Callaghan is a natural health blogger and food freedom activist. You can see her work at NaturalBlaze.com and ActivistPost.com. Like at Facebook.

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