Omega-3 fatty acids
Omega-3 fatty acids contribute to health in many ways. Our cells cannot make omega-3 fatty acids so we must consume them. The most health-promoting omega-3 fatty acids are eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA). Foods that contain EPA and DHA are fish, seafood, grass-fed beef, algae, seeds, and nuts. Omega-3 fatty acids in plant foods are comprised of alpha-linolenic acids (ALA). Once ingested, ALA is broken down into EPA and DHA.
Deficiencies
The optimal blood level of omega-3 is expressed as a percentage of the fatty acids in red blood cell membranes which are EPA and DHA. The optimal level of omega-3 fatty acids are approximately 8%. Vegetarians can be deficient in EPA and DHA because it is difficult for the body to convert sufficient ALA into enough EPA and DHA. Additionally, anyone who does not regularly eat seafood, seeds, and nuts may be deficient.
There are blood tests available to check blood levels of omega-3 and other fatty acids with the most well-studied test being the OmegaQuant®. These tests can be self-ordered or ordered by healthcare practitioners although they may not be covered by insurance.
While deficiency of omega-3 is rare, most modern Western diets have too much omega-6 fatty acids that are found in a wide variety of grains and processed foods, and not enough omega-3s. This relative deficiency is linked with inflammatory joint pain, impaired immunity, increased risk of coronary artery disease, and increased risk of muscle wasting (sarcopenia). Omega-3 deficiency can be addressed with diet and/or supplementation.
Role of Omega-3 fatty acids in cancer
Having sufficient omega-3 fatty acids may be associated with a lower risk of cancer, especially colon and breast cancers.
Omega-3 supplementation with conventional chemotherapy treatment may improve the anti-cancer effects of the chemotherapy, especially for colorectal cancer, breast cancer and non-small cell lung cancer. Omega-3 fatty acids can also improve tolerance to conventional treatment by reducing joint pain, supporting a balanced mood, lowering the risk of peripheral neuropathy, and decreasing the risk of loss of lean muscle.
Type and Dose
Supplemental omega-3 is most commonly in the form of fish oil, with algae oil or ground flaxseeds appropriate for vegetarians. Although fish oil supplements are commonly available, the quality varies considerably. Because fish oil can be contaminated with heavy metals, fish oil products should be tested for heavy metals, especially mercury. Fish oil can also become rancid, especially when packaged in clear bottles which allows light to oxidize the fatty acids. Rancid fish oil will have a strong fishy odor.
The dosage of fish oil varies depending upon the indication for its use. Nonetheless, a commonly studied and recommended dose is between 1g – 2g of omega-3 daily as EPA and DHA. Fish oil supplements should always be taken with food to avoid fishy burps.
Warnings
High doses of fish oil can cause diarrhea, nausea, and fishy burps. Your doctor may want you to stop taking fish oil prior to surgery due to concerns about increased bleeding risk. While clinical research has not proven this risk, caution and health provider supervision is best for someone undergoing surgery. Additionally, if you are taking a blood thinner (anti-coagulant), fish oil should be discontinued.
