Omega 3 and Tumors

Omega-3 fatty acids are types of polyunsaturated fats found in fish and plant oils that are essential for brain development, immune reactions and cellular structure. The American Heart Association and other leading health care organizations acknowledge the importance of consuming omega-3 fatty acids to lower risk of cardiovascular diseases and promote general wellness. Omega-3 fatty acids are popular dietary supplements sold in the United States; however, there is not enough evidence to support their effects on cancer prevention or treatment. Consult with your physician before increasing your intake of omega-3 fatty acids.

Composition

Omega-3 fatty acids have a long carbon chain with multiple double bonds. Their distinguishing feature is a double bond located three carbons away from the omega end of their carbon chain. The three primary types of omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA is an essential fatty acid and must be obtained through foods or supplements. EPA and DHA are not essential because they can be made by the body using ALA as a substrate. EPA and DHA can also be obtained through food or supplements.

Prevention

Inside the body, ALA and EPA generate anti-inflammatory molecules, called eicosanoids, that influence many physiological properties including tumorogenesis. Tumor growth is associated with increased inflammation, and omega-3 fatty acids may slow tumor growth by reducing inflammation. However, a 2006 systematic review published in the "Journal of the American Medical Association" did not find a significant association between omega-3 fatty acid intake and cancer incidence. More research is needed to determine whether omega-3 fatty acids are beneficial for the prevention of cancer.

Treatment

The anti-inflammatory properties of omega-3 fatty acids may also have therapeutic value during cancer treatment. A common and potentially life-threatening condition, called cancer cachexia, defined by the National Cancer Institute as, "advanced protein-calorie malnutrition and is characterized by involuntary weight loss, muscle wasting, and decreased quality of life," is also marked by increased inflammation. According to a summary by the National Cancer Institute published online in their "Nutrition in Cancer Care (PDQ): Tumor-Induced Effects on Nutritional Status" in 2011, preliminary clinical studies suggest a benefit in omega-3 fatty acid supplementation for the treatment of cachexia, however, larger clinical research trials are needed to ascertain the safety and efficacy of their usage.

Recommend Intake and Dietary Sources

Although research for the use of omega-3 fatty acids and tumor growth is inconclusive, the American Heart Association, American Institute for Cancer Research, and Institute of Medicine advocate meeting the adequate intakes for essential fatty acids to maintain health and well-being. The adequate intake for alpha-linolenic acid is 1.6 g per day for adult men, and 1.1 g per day for adult women. Eating 3-ounce servings of different types of fatty fish twice a week is sufficient to meet your needs. Dietary sources of omega-3 fatty acids include cold water fish suck as tuna, salmon, mackerel, herring and sardines, flaxseed, walnuts, pecans, canola oil, olive oil, green leafy vegetables like spinach and kale, Brussels sprouts, cauliflower, and various nuts and seeds.

Considerations

Fish and fish oil supplements that are rich in omega-3 fatty acids may also contain mercury and other compounds that pose health risks. Consult with your physician to determine the right amount and type of fish or supplements you need to meet your daily needs for omega-3 fatty acids.