Can Fish Oil Help Beat Cancer?

Omega-3 fatty acids could boost the impact of chemotherapy in breast cancer patients

By Amie Filkow for Thought Box, University of Alberta


What if eating simple fish oil could boost the power of chemotherapy drugs to kill cancer cells? It’s no longer a “what if” question.

UAlberta nutritional scientist Catherine Field, ’88 PhD, has found that an omega-3 fatty acid found in some fish, supplements and fortified foods improved the action of the chemotherapy drug doxorubicin on cancer cells. “When human breast tumours were treated with the fatty acid DHA before chemotherapy, more malignant cells died than with chemo alone,” Field says.

In other words, treating the tumours with DHA before chemo killed more cancer cells — even more than when two or more kinds of chemotherapy drugs were combined.

What made researchers think to connect omega-3s and cancer?

The research actually started with a question Field heard over and over again from breast cancer patients: what should we be eating while we undergo chemo and afterward?

Field, a professor from the Faculty of Agricultural, Life and Environmental Sciences, was investigating the impact of exercise in post-breast cancer therapy as part of a project with her UAlberta colleagues in oncology and the Faculty of Physical Education and Recreation. She sat in on breast cancer support groups and heard patients lament the lack of information about nutrition during cancer therapy. “Women asked so many questions about nutrition during and after their treatment, but we had no science-based answers.”

Field, who is also a registered dietician, proposed the idea that omega-3 fatty acids — long recognized as important nutrients — could be used in the treatment of breast cancer.

What does this mean for people with cancer?

It’s still early, but there’s promise here. The initial research is being done in non-human models. If the findings hold true in human trials, it would mean breast cancer patients could take omega-3 supplements — in a drink or intravenously — to improve the effectiveness of their chemotherapy drugs. In some cases it could even cut a patient’s chemo dosage and lessen severe side-effects. “There’s good evidence that many cancer side-effects are things that need essential fatty acids,” says Field. “We’ve seen symptom improvement in lung cancer, but not yet in breast.”

Does this have implications for the average person?

Considering that two out of five of us will get cancer in our lifetimes, yes, it does. It holds out the hope that cancer treatment of the future could be gentler and more effective at the same time.

It also points to a societal shift that is beginning to look at the bigger picture of medicine and health. Nutrition has traditionally been seen in a different realm from cancer treatment — usually in relation to quality of life and palliative care, where it’s important to make sure patients who have often stopped eating are getting enough calories. “In breast cancer, nutrition has not really been on the radar,” says Field, a co-director of UAlberta’s new Cancer Research Institute of Northern Alberta (CRINA).

What’s next?

Field’s team is conducting a final trial in non-human models and hopes to find funding for a small human trial next year. If that’s successful, the plan is to conduct a clinical trial with more patients to prove the treatment works in humans. Field estimates the therapy is about five years away from clinical use.

Beyond that, the team is digging deeper into how and why DHA has this impact, whether other types of omega-3s could improve treatment and whether these essential fatty acids can also protect against cancer.

A nutritionist working with an exercise researcher — that seems like an unusual mix.That’s not all. Agricultural researchers are also part of the equation: Field is partnering with a UAlberta oilseed biotechnology team and the Alberta Canola Producers Commission to develop crops of canola and flax rich in anti-cancer omega-3s, growing their own dietary sources for this novel treatment. Soon, she’ll be working with UAlberta oncologist John Mackey, ’90 MD, to get the treatment from the research lab to cancer patients.

This kind of approach is called “translational research.” It brings together researchers from diverse fields who work at different points on the spectrum from basic research to patient care. The goal is to share insights, expertise and ideas to improve cancer detection and treatment. Read more about it in “Teaming Up to Conquer Cancer.”

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