shutterstock_29310922What’s the big deal with fish oil and omega-3 essential fatty acids?

I am often asked by my patients whether or not they really need to take omega-3 supplements (commonly known as “fish oil”). They follow up this question with another two part question, “how much should I take?” and “what is the best kind?” I hope to answer these questions in this week’s blog.

EFAs: The Essentials

First, let’s try to sort out the confusion many people have regarding omega-3 essential fatty acids (EFAs).

Omega-3s are part of a group of fats called essential fatty acids (EFAs). EFAs are considered essential because 1) our bodies cannot manufacture them (they must be acquired through the foods we eat), and 2) without them our bodies will suffer illness or disease. The other EFAs our bodies need are omega-6s and omega-9s.

shutterstock_118789042Omega-3 EFAs. There are three different kinds of omega-3 EFAs: alpha linoleic acid (ALA) and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Dietary sources of omega-3 EFAs include:

  • ALA: flax, hemp seeds, chia seeds, and walnuts
  • EPA/DHA: fatty fish such as herring, mackerel, salmon, sardines trout, and tuna (hence the term, “fish oil”)

Also, our bodies can make EPA and DHA from ALA but it takes a long time and some sources say only about 2% of ALA is converted into DHA/EPA.

Omega-6 EFAs. The three types of omega-6s are linoleic acid (LA), gamma linolenic acid (GLA) and arachidonic acid (AA). Dietary sources of omega-6s include:

  • LA: most vegetable oils, such as corn, safflower, sesame, soy, and sunflower seed
  • GLA: black currant, borage, and evening primrose oil
  • AA: beef from grain (corn)-fed cows and eggs from grain (corn)-fed chickens

Omega-9 EFAs. Most monounsaturated fat in the human body is in the form of omega-9s. Avocados, canola oil, olives, olive oil, and various nuts and seeds are dietary sources of monounsaturated fat. These types of fats have been shown to lower LDL (“bad cholesterol”) levels (J Nutr. 1999; 129:2280-2284).

shutterstock_121205329---webHow EFAs Affect Our Health

When we look at the ratio of omega-6 (AA) to omega-3 (EPA) in our food supply we can get a sense of how our society’s health is being affected. A hundred years ago in the U.S. and today in regions with lower cardiovascular disease such as Okinawa, Japan, we see a ratio of less than 4:1. However, now in the U.S. we are seeing ratios as high as 50:1 (Rizzo, et al. Lipids in Health and Disease 2010.) This comes from eating meat from industrialized livestock that has a higher omega-6:3 ratio because the animals are being fed large quantities of corn (a government subsidized crop).

This is why we see such amazing benefits from increased omega-3 consumption in our diets, from flax seeds to fish to supplements containing omega-3s. Omega-3s play a key role in a number of important metabolic processes such as:

  • Keeping cell membranes fluid, flexible, and permeable to function properly
  • Reducing pro-inflammatory signals and activities
  • Scavenging free radicals (highly reactive molecules that can cause cellular death)
  • Promoting healthy blood flow and reducing clotting
  • Reducing unhealthy cholesterol levels and triglycerides

What Amounts of Omega-3 EFAs Should We Be Getting?

I recommend that my patients eat a diet rich in plant fats such as flax seeds, nuts, avocados and olive oil. I also recommend eating 2-3 servings of fish per week. In addition to this I may recommend taking supplements rich in EPA and DHA, typically in doses of 800mg EPA and 500mg of DHA per day. One serving of three ounces of salmon is equivalent to approximately 1 gram of fish oil supplementation per day for one week.

To further improve the omega 6:3 ratio I also recommend reducing consumption of omega-6 EFAs from processed and fast foods and polyunsaturated vegetable oils (corn, sunflower, safflower, soy, and cottonseed, for example).

Research on the Health Benefits of Omega-3s

The roles of EPA and DHA in supporting cardiovascular health, central nervous system function, eye health, and fetal nervous system development are well documented. Additionally, a growing body of evidence suggests that specific omega-3s may be advantageous in the management of other chronic diseases with an inflammatory component, such as asthma, inflammatory bowel disease (Crohn’s disease, ulcerative colitis), and rheumatoid arthritis. (Ann Nutr Metab. 2009;55:123-139.)

shutterstock_121294759_webCardiovascular benefits. The vast majority of research has focused on the cardioprotective benefits of omega-3s. For example:

  • In the 1970s Bang and Dyerberg established that the low death rate from heart disease (then at only 3.5%) in Greenland Eskimos was partially due to blood-thinning effects of diets rich in omega-3s, especially EPA. (Am J Clin Nutr. 1980;33(12):2657-2661.)
  • A review of three prospective epidemiological studies published in Circulation concluded that men who ate fish at least once a week had lower levels of coronary heart disease (CHD) mortality than men who ate no fish. (Circulation. 1996;94:2337-2340.)
  • The Nurses’ Health Study reported an inverse relationship between 1) omega-3 fatty acid intake from fish and 2) death from CHD in women. Compared with women who ate fish less than once per month, the risk for CHD death was reduced with greater fish consumption. The relative risk for those who consumed fish one-to-three times per month was 79%; once per week (71%), two-to-four times per week (69%); more than five times per week (66%).(JAMA. 2002;287:1815-1821.)

Mental and central nervous system benefits. Omega-3s are often referred to as “brain food,” and for good reason: DHA is the predominant fatty acid in the central nervous system and plays an important role in neural development and function. (Indian J Pediatr. 2005;72(3):239-242.)

  • Epidemiological evidence suggests that high polyunsaturated fat intake may have a protective effect against the development of mild cognitive impairment. Possible mechanisms include the presence of antioxidant and anti-inflammatory compounds in omega-3 rich foods and the effect of omega-3s on maintaining the structural integrity of neuronal membranes.(Ageing Res Rev. 2010;9(2):184-199.)
  • Three randomized controlled trials suggest that DHA supplementation improved cognitive function in nine-month old infants. (Child Dev. 2009;80(5):1375-1384.)
  • A review of research involving patients with major depressive and bipolar disorder found convincing evidence for beneficial effects of omega-3s, especially EPA. (Lipids Health Dis. 2007;6:21.)

shutterstock_97744304_webEye health. DHA, found in high concentrations in the retina, has been shown to have an important role in supporting eye health. For example:

  • Researchers at the Louisiana State University Neuroscience Center of Excellence reported that DHA protects retinal cells from degenerative diseases, such as retinitis pigmentosa and age-related macular degeneration (AMD). (Trends Neurosci. 2006;29(5):263-271.)
  • A literature review on the PubMed, ScienceDirect, and Ovid databases found evidence that omega-3 supplementation may be beneficial in the treatment and prevention of dry eye syndrome. (Cont Lens Anterior Eye. 2010;33(2):49-54.)
  • A double-masked, randomized, controlled, parallel-group, prospective, dose-response study found that infants who were fed a DHA-fortified infant formula had better vision when compared to infants fed a non-supplemented formula. (Am J Clin Nutr. 2010;91(4):848-859.)

Food or Supplements?

Due to concerns over the level of mercury and other contaminants in fish and shellfish, the U.S. Food and Drug Administration and Environmental Protection Agency in 2004 issued a joint advisory to women of childbearing age and young children to avoid certain large species of fish and limit their consumption of other fish to two average meals a week.

If you’re concerned about seafood contamination or if your health status requires high dosages of omega-3s, a dietary supplement may be a better option. But be aware that in my experience, not all fish oil supplements will deliver the benefits that my patients are looking for. Some companies add toxic fillers like trans-fats or have impurities such as mercury.

The fact is that product quality can vary widely from one manufacturer to another. In choosing one brand over another, be sure to pay careful attention to the following:

  • Quality. Look for products that meet or exceed the standards set by highly respected organizations such as the U.S. Food and Drug Administration (Good Manufacturing Processes), International Pharmacopoeia, the Council for Responsible Nutrition (Omega-3 Monograph), and the Global Organization for EPA and DHA Omega-3 (GOED). (Note: some omega-3 products claim to be “ultra pure” or “ultra refined.” But these are merely marketing terms; they are not actual standards of quality.)
  • Stability. Is the supplement antioxidant stabilized? Antioxidants such as tocopherols and rosemary are often added to omega-3 supplements to protect against rancidity. Avoid any product that smells rancid or looks cloudy.
  • Delivery form. Having the right product in the right delivery form-liquid, softgel, or chewable-can make following the plan prescribed by your healthcare provider a lot easier. Be sure the omega-3 supplement you’re buying fits your individual preferences.
  • “Fishy” taste. Less refined products may have a fishier taste and some individuals are more prone to “burp-up” (repeating) that leaves a fishy aftertaste for hours afterward–even with higher quality products. These common unpleasant side effects can be reduced by using products with added citrus flavors or that are enteric-coated to prevent the oils from releasing before they reach your small intestine.

Net the Benefits of Omega-3s

Omega-3 EFAs are essential nutrients with well-documented health benefits. Although sources are plentiful, the increase in inflammatory-related chronic diseases, most notably cardiovascular disease, suggests that most people aren’t getting enough of this vital nutrient. Fortunately, this can be easily remedied by consuming a more healthful balance of omega-3 and omega-6 EFAs to support your unique health needs.