fish oilFish oil is a supplement with a history that both predates the modern pharmaceutical industry and is widely accepted today for therapeutic use in mainstream medicine.  The benefits of fish oil come from the omega-3 fatty acids that it contains.  These polyunsaturated fats cannot be manufactured by the body, but must be obtained from dietary sources.  Omega-3s are necessary for numerous body functions and normal growth and development, and research suggests that a diet high in omega-3s is associated with many health benefits, including protection against heart attacks, stroke, autoimmune disease, and cancer.  As fish oil is derived from fish, one of the most nutrient-dense Paleo foods, many people may be under the assumption that supplementing with fish oil is safe and beneficial.  But don’t grab the first bottle off the shelf too quickly—in the case of fish oil supplementation, there is much more to the story.

Types of Omega-3s

There are three types of omega-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).  ALA is rich in seeds, such as flax, hemp, and chia, while EPA and DHA are found in high amounts in cold water oily fish, including sardines, salmon, and herring.  EPA and DHA are also found in lesser amounts in pastured meats and eggs.  ALA can be converted to EPA and DHA by the body, but this conversion is notoriously inefficient with a conversion rate of 6% or less.  Because of the inefficiency of converting ALA to EPA and DHA, it is best to obtain the majority of omega-3s in the diet from fish or other animals rather than plant-based sources.

Balance of Omega-3s and Omega-6s

Omega-6s are another type of essential polyunsaturated fatty acids.  Although they have a reputation as being a “bad” fatty acid, omega-6s are as important as omega-3s for healthy functioning of the body and also must be obtained from dietary sources.  Omega-3s and omega-6s are precursors to prostaglandins, which are hormone-like substances that control many processes in the body, including inflammation.  To simply the complex prostaglandin pathways, the omega-3 pathway produces anti-inflammatory prostaglandins, while the omega-6 pathway can lead to both anti-inflammatory and pro-inflammatory end-products.  Inflammation is a normal response to injury or damage in the body and both pro-inflammatory and anti-inflammatory prostaglandins play a critical role in the healing process.  Uncontrolled inflammation, however, is responsible for the majority of the diseases of modern civilization and this can be attributed to a fundamental shift in the balance between omega-3s and omega-6s in the diet.  In order for the omega-6 pathway to favor the production of anti-inflammatory prostaglandins, there must be an adequate amount of omega-3s present.  An over-abundance of omega-6s compared to omega-3s will shift the balance toward a greater production of pro-inflammatory prostaglandins, leading to the uncontrolled inflammation that results in disease.  In the Paleolithic diet, the balance of omega-3s to omega-6s was in the range of 1:1 to 1:3.  The ratio in the typical Western diet is 1:10 to 1:20 due to the increased consumption of vegetable oils and grain-fed meats.  The goal of fish oil supplementation is to increase the ratio of omega-3s to omega-6s and thereby encourage a greater production of anti-inflammatory prostaglandins.  Although fish oil is one of the most popular supplements on the market, there are plenty of reasons why getting your omega-3s in supplement form may not be the best choice.

Concerns with Fish Oil Supplements

The polyunsaturated fats in fish oil are highly unstable and easily damaged.  There are a number of different ways that fish oil is extracted, but almost all processing will result in some amount of oxidative damage from exposure to heat, air, and light.  Improper handling and storage also leads to rancidity.  If the fish oil supplement you buy isn’t already rancid while still sitting on the shelf, it is likely to become so prior to the expiration date listed on the bottle.  In addition, there are concerns with contaminants in fish oil supplements, such as PCBs and mercury.  A recent high profile study that found an association between fish oil supplementation and increased prostate cancer risk has called into question the benefits of obtaining omega-3s in supplement form.  There are a number of methodological problems with this study, but a plausible explanation for conflicting findings on the benefits of fish oil in this study and others may be due to the rancidity and contaminant factors.  Consuming damaged, toxic omega-3 fatty acids may cause more harm than good in the body, especially when used on a long-term basis.

Fermented Cod Liver Oil

Fermented cod liver oil is a whole food supplement that is made by a traditional fermentation process rather than the heat processing that is used to manufacture most fish oil supplements.  Fermented cod liver oil does contain a small amount of omega-3 fatty acids, but its primary health benefits are due to the presence of the fat soluble vitamins A, D, E, and K2.  The omega-3s present in fermented cod liver oil are more bioavailable and easily used by the body than those in fish oil supplements, but if you are solely interested in improving your omega-3 to omega-6 fatty acid balance, there are better dietary approaches.

Whole Food Approaches to Balancing Omega-3s and Omega-6s

By adopting a Paleo template that excludes foods high in omega-6 fatty acids, such as processed vegetable oils, grains, and legumes, you have already drastically improved the balance of omega-3s to omega-6s.  With such a diet, fish oil supplementation is not necessary for the majority of people.  Instead, increase the omega-3s in your diet by eating cold water, oily fish a few times a week and opting for pastured meats rather than grain-fed.  If you have an inflammatory disease process, you may want to consider limiting your consumption of nuts rich in omega-6s, such as almonds, pecans, pistachios, and Brazil nuts.

If you do decide to supplement with fish oil, choose your supplement carefully.  The International Fish Oil Standards Program is a third party testing and certification program for fish oil supplements.  This resource can help you make an informed choice when purchasing fish oil.

Do you use supplement with fish oil?  Do you think it’s necessary when consuming a nutrient-dense Paleo diet?  Please leave your thoughts and comments below! 

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