Omega-3 Fatty Acids
Also known by these names
Nancy Hepp, MS, BCCT Project Manager
Laura Pole, RN, MSN, OCNS, BCCT Senior Researcher
Last updated August 19, 2021.
Omega-3 fatty acids are a type of polyunsaturated fatty acid (PUFA) found naturally in these foods and supplements:
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
- No improved survival with supplementation5
Lab and Animal Evidence
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
Body Weight and Composition
Gastrointestinal Effects, including Nausea and Vomiting
Other Side Effects and Symptoms
Reducing the risk of developing cancer or the risk of recurrence
Lab and Animal Evidence
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)
- Cardiovascular activity
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.
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:
- Solutions 4 Health:
- Breast Cancer Wellness Plan
- Colorectal Cancer Wellness Plan
- Endometrial Cancer Wellness Plan
- Lung Cancer Wellness Plan
- Prostate Cancer Wellness Plan
- Natural Medicines Database (requires purchase)
- Also see the protocols listed below.
Integrative Programs, Protocols and Medical Systems
|For more information about programs and protocols, see our Integrative Programs and Protocols page.|
- Programs and protocols
- Alschuler & Gazella complementary approaches99
- Block program100
- Breast cancer case study
- Lung cancer case study
- Prostate cancer case study
- Core diet plan
- Remission support diet
- Chemotherapy coupler
- Radiation therapy coupler
- Normalizing coagulation
- Blocking inflammation
- Blocking tumor-fueling enzymes
- Boosting immune surveillance
- Self-care program for stress chemistry and circadian rhythm
- Chang strategies101
- Lemole, Mehta & McKee protocols102
- MacDonald breast cancer program103
- McKinney protocols104
- Parmar & Kazcor treatment plans105
- Traditional systems
Non-cancer Uses of Omega-3 Fatty Acids
BCCT has not reviewed the effectiveness of this therapy for non-cancer uses.
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.
- Memorial Sloan Kettering Cancer Center’s About Herbs website: Omega-3
- Deng G, Gubili J. Omega-3 Fatty Acids. ASCO Post. March 10, 2019.
- American Institute for Cancer Research website: more than 100 articles and scientific reports on omega-3 fatty acids and cancer
- TRC Natural Medicines website (subscription is required): in-depth information, ratings of effectiveness and safety and evaluation of specific omega-3 fatty acid products
- Consumer Labs: Product Review (subscription required): Fish Oil and Omega-3 and -7 Fatty Acids Supplement Review
- Moss Reports (purchase required): Select from the list of cancers down the left side of the page for a report describing uses of conventional, complementary, alternative and integrative therapies related to that cancer. Ralph Moss is among the most knowledgeable and balanced researchers of integrative cancer therapies. The cost of his Moss Reports is not negligible, but many patients find them of considerable value. Moss is also available for consultations.
- Harvard Health Publishing: Should you be taking an omega-3 supplement?
- Linus Pauling Institute, Oregon State University: Essential Fatty Acids
- Gurdev Parmar and Tina Kaczor: Textbook of Naturopathic Oncology
- Dawn Lemanne and Victoria Maizes: Advising Women Undergoing Treatment for Breast Cancer
- Block KI, Block PB, Gyllenhaal C: Integrative Treatment for Colorectal Cancer
- Keith Block and others: A Broad-Spectrum Integrative Design for Cancer Prevention and Therapy
- Raymond Chang, MD: Beyond the Magic Bullet: The Anti-Cancer Cocktail
- Donald I. Abrams, MD, and Andrew T. Weil, MD: Integrative Oncology, 2nd Edition
- Neil McKinney, BSc, ND: Naturopathic Oncology, 3rd Edition
- Ted Schettler, MD, MPH: The Ecology of Breast Cancer: The Promise of Prevention and the Hope for Healing
- Lise Alschuler, ND, FABNO, and Karolyn Gazella: The Definitive Guide to Cancer, 3rd Edition
- Keith I. Block, MD: Life over Cancer: The Block Center Program for Integrative Cancer Treatment
- Lorenzo Cohen and Alison Jefferies: Anticancer Living: Transform Your Life and Health with the Mix of Six
- National Cancer Institute: Office of Cancer Complementary and Alternative Medicine
- Lone Star Medical Group: Natural Alternative Treatments
- Michael Lerner: Choices In Healing: Integrating the Best of Conventional and Complementary Approaches to Cancer