What Are Omega-3s?
Many of you have probably heard that fish oil is a good source of “omega-3s” but maybe don’t know exactly what that means. Three main classifications of fats are saturated, monounsaturated, and polyunsaturated – differentiated by their chemical structure. Most fat-containing foods are made up of more than one type, in varying amounts. Understanding these different kinds of fats and fatty acids in detail can be daunting. Since fish oil is currently a hot topic in the health and wellness world, we’ll just focus on omega-3s for now, along with the “fat family” they belong to.
Omega-3 fatty acids are a type of polyunsaturated fatty acid, as are omega-6 fatty acids. Alpha-linolenic acid (ALA) is one type of omega-3 and linoleic acid (LA) is one type of omega-6. LA and ALA are considered “essential fatty acids” (EFAs). These two are considered essential because they are necessary for health, but cannot be synthesized in the body. Therefore, they must be obtained through food or supplements.
EFAs: Their Role in Health
LA and ALA are extremely important to overall health because they are used to make and maintain cell membranes. They also form eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, which are hormone-like substances that control cell growth, blood pressure, immune response, inflammation, and platelet aggregation. EFAs have also been shown to control gene expression. EPA and DHA, two other types of omega-3 fatty acids, are considered “conditionally essential.” They are called this because unlike LA and ALA, they can be made within the body from ALA, but there is a poor conversion rate. This process is dependent on several factors, but in general, this means that many people are not getting (or making) enough DHA and EPA.
A deficiency of essential fatty acids can cause various health problems, including dry/scaly skin, increased risk of infection, poor growth in children, and slow wound healing. Individuals with chronic fat malabsorption (as seen in those with certain digestive disorders) and those with cystic fibrosis are at increased risk for deficiency. Omega-3 fatty acids in particular have gained more attention recently. This is due to the growing body of research demonstrating that the balance between omega-3 fatty acids and omega-6 fatty acids in the diet, in addition to the individual amounts consumed, is crucial to health.
The Standard American Diet (SAD) is extremely lopsided in favor of omega-6s. An optimal ratio of omega-6s to omega-3s is 1:1 or 2:1, which is closer to what our ancestors and other cultures traditionally consumed. It is estimated that many Americans eat a ratio of 20:1 or even higher in some cases! Let’s explore the benefits of increasing dietary omega-3s (and decreasing omega-6s) in order to achieve a more favorable balance.
Omega-3s and Inflammation
The eicosanoid products of most types of omega-6s (with gamma-linoleic acid being the exception, as is found in evening primrose oil and borage oil) have been shown to promote thrombosis and inflammation. As a result, they are thought to play a role in the high prevalence of atherosclerosis, obesity, and other inflammation-related conditions found in Westernized cultures.
Just about every chronic disease has now been linked with inflammation in the body, including depression, diabetes, neurodegenerative diseases, and even cancer. An increase in omega-3 fatty acid intake has been shown to have anti-inflammatory effects and cultures with regular consumption have lower rates of these types of diseases. Higher ratios of omega-6s to omega-3s can increase leptin resistance and insulin resistance, which are underlying causes of obesity. Inversely, decreasing the ratio has been shown to prevent obesity in animal models.
Fish vs. Flax
At this point, you may be thinking, what about flax? Flaxseed is indeed a rich source of ALAs, along with chia and perilla seeds, walnuts, and green leafy vegetables (ALA is found in the chloroplasts of plants). Unfortunately, the body generally converts less than 20% of dietary ALA to EPA and DHA. Higher consumption of omega-6s and trans fats, as well as gender and genetic differences, can all negatively affect this conversion. Therefore, it is best to eat a variety of both ALA and EPA/DHA sources. High amounts of DHA and EPA are found in fish oil, the most concentrated food source of omega-3s (30% of its total fat content).
Although we’ve talked about LA as an essential fatty acid, oils from these high omega-6 sources can go from being healthful fats to a health nightmare when they are consumed in large amounts (and especially in comparison to omega-3s). This is the case with the Standard American Diet. These high omega-6 oils include corn, sunflower, safflower, cottonseed, and soybean. Using this knowledge to get closer to the recommended 2:1 or 1:1 ratio is a huge step toward optimal health and the management of a variety of diseases.
The American Heart Association recommends that all adults eat at least 2 servings of fish per week, which translates into about 500 mg of EPA and DHA. This recommendation is even higher for those with established cardiovascular disease – 1-4 grams per day depending on other risk factors. Pregnant and breastfeeding women should get a minimum of 2-3 servings per week, due to the importance of DHA in things like healthy brain and eye development. Increasing omega-3 fatty acid intake has been shown to improve or help prevent a variety of conditions, including:
- Cardiovascular disease
- High triglycerides
- Rheumatoid Arthritis and other autoimmune conditions
- Skin disorders
- Alzheimer’s disease
- Mood disorders
Unfortunately, much of the commercially sold fish supply is contaminated with methylmercury or polychlorinated biphenyls (PCBs), which both can have detrimental effects on health. This is especially a concern for pregnant and breastfeeding mothers and the chronically ill. Generally, fish lower on the food chain (smaller fish) have lower amounts of mercury. The Environmental Working Group has evaluated different kinds of seafood to identify those with the highest omega-3 content and the lowest mercury contamination. Here are their recommendations for best and next best choices – and the ones to avoid:
- Rainbow trout
- Atlantic mackerel
- King mackerel
- Orange roughy
Fish oil supplementation should be considered as a primary or additional source of omega-3s in several circumstances. If you need therapeutic doses due to a chronic inflammatory condition, are pregnant or breastfeeding, want to minimize your exposure to environmental contaminants, or just don’t care for seafood, a good quality supplement is a great choice. Supplemental fish oil has been shown to be naturally low in mercury, since it is a toxin that is stored in the muscle of the fish rather than in the fatty/oily part. Ultra Omega, formulated by Holtraceuticals, provides nearly 1 gram of omega-3 fatty acids per serving, including DHA and EPA. Since an increase in dietary polyunsaturated fatty acids creates a higher need for vitamin E, it is added to this formula to help protect the body from free radicals. Many supplement manufacturers that sell over-the-counter fish oils do not take this step in quality assurance.
Since fish oil is so effective at naturally inhibiting platelet aggregation, it’s important to discuss supplementation with a healthcare provider if you are on blood-thinning medications. Depending on the source of the fish oil, those with fish or shellfish allergies may need to seek out an alternative, such as an algae-based omega-3 formula.
1. Environmental Working Group. EWGs Consumer Guide To Seafood. Available at: http://www.ewg.org/research/ewgs-good-seafood-guide/ Accessed on April 8, 2016.
2. Bland, J, Costarella, L, Levin, B et al. Clinical Nutrition: A Functional Approach, 2nd Ed. Gig Harbor, WA: IMF; 2004
3. Linus Pauling Institute. Essential Fatty Acids. Available at: http://lpi.oregonstate.edu/mic/other-nutrients/essential-fatty-acids/ Accessed on April 8, 2016.
4. Holtraceuticals. Ultra Omega: Essential Fatty Acid Support. Available at:https://www.holtraceuticals.com/shop/ultra-omega/ Accessed on April 12, 2016.
5. Simopoulos, AP. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk of Obesity. Nutrients. 2016 Mar 2; 8(3): pii.E128.doi 10.3390/nu8030128.
6. Zimmermann, M. Burgerstein’s Handbook of Nutrition: Micronutrients in the Prevention and Therapy of Disease. New York, NY: Thieme; 2001.