Can Fish Oil Really Prevent Cancer?

Fish oil is known for purported cancer prevention properties.

One study showed that DHA (decosahexaenoic acid—one of the fatty acids in fish oil) stopped or reversed tumor growth of neuroblastoma, a deadly tumor that affects children. Six to nine percent of childhood cancers are neuroblastomas. In this study, high doses of DHA decreased normal tumor growth by about two-thirds in laboratory rats.

Fish oil contains significant amounts of Omega-3 fatty acids, which are critical for brain function and normal growth and development. Omega-3 contains the fatty acids DHA and EPA (eicosapentaenoic acid). Both are essential for good health.

Fish oil reduces inflammation and may lower your risk for heart disease, cancer, and arthritis. There are two types of omega fatty acids: Omega-3 and Omega-6. Both are necessary; however, we need a higher ratio of Omega-3s to Omega-6s.

This study supports earlier research that found adding fish oil to your diet inhibits other types of cancer, including breast, small and large intestine, lung, colon, and prostate. Fish oil works better at preventing cancer than treating it after it develops.

A large study from South Korea (where the incidence of breast cancer is above average) found that a high intake of fatty fish was associated with a reduced risk for breast cancer in both pre- and post-menopausal women. The more fish oil the women consumed, the greater the protective factor.

Previous research of fish oil on breast cancer returned mixed results, largely due to the design of the studies and the influence of ethnicity. For example, Japanese post-menopausal women who increased their fish intake had a significant decrease in breast cancer risk.

Earlier this year, another study found that regular use of fish oil supplements produced a 32 percent reduction in the risk of developing invasive ductal breast cancer, the most common type of breast cancer.

Many scientists believe that cancer is a metabolic disease. To remain viable and perform their genetically programmed function, cells must produce usable energy. The process for producing energy is different between normal cells and tumor cells. Researchers have found that reducing glucose (a primary ingredient in energy production) through dietary calorie restriction deprives tumors of necessary nutrients. The Omega-3 fatty acids in fish oil help maintain low glucose levels during dietary restriction.

You consume Omega-3 fatty acids when you eat fish such as salmon, tuna, and halibut, other seafood, some plants, and nut oils. A daily high-quality fish oil supplement will ensure you get adequate levels of Omega-3s.


"Fish Oil and Cancer-New Findings." Web. 6 June 2010.,english/

"Fish Oil and Cancer-New Findings, Part II." Web. 13 June 2010.,english/

Gleissman, H., SegerstrÃm, L., Hamberg, M., Ponthan, F., Lindskog, M., Johnsen, J.I., and  Kogner, P. "Omega-3 fatty acid supplementation delays the progression of neuroblastoma in vivo." International Journal of Cancer. Web. 24 May 2010.

"More on Omega-3s." Web. 20 June 2010.,english/

"Fish oil may reduce risk of breast cancer." American Association of Cancer Research press release. Web. 8 July 2010.

Seyfried, Thomas N., and Shelton, Laura M. "Cancer as a metabolic disease." Nutrition Metabolism 7 (2010): 7. Medscape Medical News. Web. 9 April 2010.