Omega-3 Fatty Acids

Also known by these names

  • O3FAs
  • ω-3 fatty acids
  • n-3 fatty acids
  • omega 3s
  • Individual O3FAs:
    • Docosahexaenoic acid (DHA)
    • Eicosapentaenoic acid (EPA)
    • Alpha-linolenic acid (ALA)

Key Points

  • Before using this therapy, consult your oncology team about interactions with other treatments and therapies. Also make sure this therapy is safe for use with any other medical conditions you may have.
  • Omega-3 fatty acids are found naturally in many fish and a few seeds and walnuts.
  • Omega-3s are widely available as supplements.
  • BCCT is interested in omega-3s because evidence shows benefits in several types of cancer treatment, and preliminary evidence shows omega-3s may reduce risks of breast and colon cancer.
  • While omega-3s are generally considered safe, a few cautions and interactions are noted.

Author

Nancy Hepp, MS, BCCT Project Manager

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Reviewer

Laura Pole, RN, MSN, OCNS, BCCT Senior Researcher

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Last updated August 19, 2021.

Omega-3 fatty acids are a type of polyunsaturated fatty acid (PUFA) found naturally in these foods and supplements:

Expand list

The three main omega-3 fatty acids are docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and alpha-linolenic acid (ALA). DHA and EPA generally show greater benefits in cancer, but are found only in animal sources. ALA from plant sources is converted to DHA and EPA in our bodies, but with a low conversion efficiency. ALA is not recommended as your sole source of omega-3s.2

Clinical Practice Guidelines

Society for Integrative Oncology

Clinical practice guidelines from the Society for Integrative Oncology (SIO) suggest oral supplementation with omega-3 fatty acids to improve the nutritional status in people with lung cancer who have lost muscle mass (sarcopenia).3

American College of Chest Physicians

2013 evidence-based clinical practice guidelines from the American College of Chest Physicians recommended oral nutritional supplementation with omega-3 fatty acids to improve the nutritional status for lung cancer patients with sarcopenia (loss of muscle tissue).4

Treating the Cancer

Working against cancer growth or spread, improving survival, or working with other treatments or therapies to improve their anticancer action

Clinical Evidence

General Cancer

  • No improved survival with supplementation5

Breast Cancer

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Colorectal Cancer

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Prostate Cancer

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Lab and Animal Evidence

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Managing Side Effects and Promoting Wellness

Managing or relieving side effects or symptoms, reducing treatment toxicity, supporting quality of life or promoting general well-being

Anxiety

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Body Weight and Composition

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Depression

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Fatigue

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Gastrointestinal Effects, including Nausea and Vomiting

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Pain

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Peripheral Neuropathy

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Stress

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Other Side Effects and Symptoms

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Reducing Risk

Reducing the risk of developing cancer or the risk of recurrence

Clinical Evidence

Breast Cancer

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Colorectal Cancer

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Kidney Cancer

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Lung Cancer

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Prostate Cancer

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Lab and Animal Evidence

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Optimizing Your Terrain

Creating an environment within your body that does not support cancer development, growth or spread

  • Reduced inflammation,89 or improved anti-inflammatory markers90 including when accompanying anticancer treatment91 and in patients undergoing radical colorectal cancer resection92
  • Lower markers of inflammation among healthy medical students with both EPA and DHA in a small RCT93
  • Improved immune functions in cancer patients undergoing surgery94

Modes of Action

Four mechanisms are identified:95

  • Inflammatory response
  • Brain-derived neurotrophic factor (BDNF)
  • Cortisol
  • Cardiovascular activity

Cautions

A few cautions are noted. Please see the Memorial Sloan Kettering Cancer Center’s About Herbs website for more information.

  • High blood concentrations of omega-3s are associated with increased risk of prostate cancer (see the Foundation for Alternative and Integrative Medicine for an analysis of the study that found this).
  • Increased resistance to chemotherapy is a concern;96 a type of omega-3 fatty acid, 16:4(n-3), can reduce the activity of the chemotherapy drug cisplatin. Use is not recommended on the days surrounding chemotherapy.97
  • 2018 review conclusions:98
    • Four grams of supplementation may impair clotting; patients may want to eliminate omega-3 supplements before and immediately after surgery.
    • A few adverse reactions and interactions with prescription and other drugs have been observed.

Dosing

BCCT does not recommend therapies or doses, but only provides information for patients and providers to consider as part of a complete treatment plan. Patients should discuss therapies with their physicians, as contraindications, interactions and side effects must be evaluated. Levels of active ingredients of natural products can vary widely between and even within products. See Quality and Sources of Herbs, Supplements and Other Natural Products.

Dosage recommendations are available from these sources:

Integrative Programs, Protocols and Medical Systems

For more information about programs and protocols, see our Integrative Programs and Protocols page.

Non-cancer Uses of Omega-3 Fatty Acids

BCCT has not reviewed the effectiveness of this therapy for non-cancer uses.

  • Depression
  • High cholesterol
  • Cardiovascular risk factors, including elevated triglyceride levels
  • Stroke
  • Rheumatoid arthritis
  • NSAID-associated gastroduodenal damage
  • Sunburn and sensitivity to ultraviolet radiation
  • Cystic fibrosis
  • Systemic lupus erythematosus (SLE)
  • Type 1 diabetes

Note: BCCT has not conducted an independent review of research of Omega-3 fatty acids. This summary draws from the Memorial Sloan Kettering Cancer Center’s About Herbs and other sources as noted.

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