Omega-3 Fatty Acids in Disease Prevention

herringInflammation is the basis of nearly all modern, chronic disease processes. Cancer, coronary heart disease, diabetes, and many more, all have as part of their pathology, underlying inflammatory aspects. Part of this internal environment of systemic inflammation may be in part linked to a imbalance in dietary fat intake between omega-3 fatty acids (anti-inflammatory) and omega-6 fats (pro-inflammatory). Recent research and experiential protocols have exhibited the potential for squelching the fires of inflammation via nutritional modification and therapeutic dose omega-3 supplementation. An emphasis on developing an appropriate and anti-inflammatory ratio of fats in the diet may serve to be an effective approach to preventing inflammatory-based conditions and potentially reversing diseases and conditions with a foundation in inflammatory pathways.

Omega-3 to Omega-6 Ratio

A large component regarding the research and discussion over inflammation and dietary fat intake is in reference to the balance or ratio of omega-3 to omega-6 fat intake. Researchers have displayed that pre-agricultural people in Paleolithic times thrived on a diet that was approximately 2:1 omega 6 to omega 3 fats while today in industrialized populations, the ratio may be closer to 20-30:1 omega 6 to omega 3 intake. This increase in polyunsaturated fats and industrial seed oils correlates with an increase in inflammatory disease. The chart below illustrates this trend over time:

dietary fat intake










While total fat intake has increased, noteworthy is the dramatic increase in trans fat and omega-6 fats during the last 100 years while omega-3 fat intake has decidedly decreased. Fat is not the enemy - it is this disproportionate intake of pro-inflammatory fat that serves as one of the underpinnings of chronic illness.

The anti-inflammatory benefits from omega-3, and the pro-inflammatory effect from omega-6's, are a result of the metabolic pathways and eventual metabolic byproducts created by the breakdown of each group of fatty acids. As exhibited below, omega-3 fats metabolize into EPA and DHA, that activate anti-inflammatory pathways and molecules such as series 3 prostaglandins, thromboxanes, and series 5 leukotrienes.









In a specific example of the power of omega-3's, researchers conducted a systemic review of the effects of statins and omega-3s on cardiac and overall mortality. In the study, researchers provided the subjects with the following interventions:

  • Statins
  • Fibrates
  • Resins
  • Niacin
  • Omega-3 Fatty Acid
  • Diet

Consistently in both cardiac and overall mortality, omega-3 supplementation provided the most significant benefit, even outperforming statins. Couple this efficacy with the lack of any side effects and omega-3 intervention becomes a hugely positive and promising therapy for cardiac disease.

Omega-3 Fats & Mental Health

In addition to the exciting results of omega-3 fatty acid research on inflammatory disease, mental health conditions are now also being closely studied with the potential for improvement being noted through omega-3 intervention.

The human brain is comprised of approximately 60% fat and requires a large quantity of dietary fat, specifically DHA, for optimal brain and neural development during infancy. Due to this high fat requirement of the fetus during pregnancy, researchers have postulated that post-partum depression may stem from a strong deficiency in omega-3 fatty acid. The situation would occur where the mother is already omega-3 deficient due to her genetics and nutritional intake, and then becomes even more depleted when the requirements of DHA and omega-3 are pulled from her system to that of the developing child. Researcher Jerry Cott, Ph.D. explains that "The plasma and RBC concentrations of DHA decrease during late stages of pregnancy and remain low for some time postpartum, particularly in lactating women. It is proposed that brain levels are also low during this period. Since this fatty acid is an integral component of the structural lipids of neuronal tissue, particularly synaptic terminals responsible for neurochemical transmission, DHA depletion may contribute to postpartum depression." Epidemiological evidence supports the assertion that omega-3 fats, particularly DHA, may play a role in postpartum depression:

dha depression chart












As a result of their studies, researchers published findings in the American Journal of Psychiatry that stated “Reduced maternal DHA status after the second trimester is associated with a high demand from the developing fetus for the rapid formation of its brain. Empirical studies of polyunsaturated fatty acids in the tissues, data from epidemiological surveys, and results of therapeutic trials of polyunsaturated fatty acids suggest that a deficit in omega-3 polyunsaturated fatty acids might cause major depressive disorder. Supplementation with omega-3 polyunsaturated fatty acids is thought to have protective effects for pregnancy outcome in high-risk pregnancy. Because of its safety and psychotherapeutic effects, as well as its promotion of health for mothers and their infants, treatment with omega-3 polyunsaturated fatty acids is a promising approach for pregnant patients with major depressive disorder."

With ocean fish being the most abundant and bio-available dietary source source of omega-3 fatty acids, incorporating fish into the diet of all individuals, especially pregnant mothers, becomes a viable dietary approach for ensuring optimal omega-3 intake and dietary ratio. At this juncture in the conversation over introducing more fish into the diet of pregnant mothers, the issue of mercury toxicity arises. Enter selenium.

Protective Properties of Selenium against Mercury Toxicity

For many years, women have been advised to avoid eating fish during pregnancy due to the potential for mercury toxicity in the neurological development of the fetus. Growing evidence points to  omega-3 rich ocean fish not only being healthy but essential in optimal brain and neural development of babies. At the same time, omega-3 fatty acids appear to provide preventative measures against depressive disorders in young mothers. Several leading experts in the field are now trying to turn the tide of recommendations towards increasing omega-3 fish in the diet during pregnancy. These experts acknowledge the issue of mercury toxicity but put it in context with the protective qualities of selenium.

Selenium is a trace mineral found in large abundance in ocean fish. Selenium (Se) is absolutely required for the activity of 25-30 genetically unique enzymes (selenoenzymes). All forms of life that have nervous systems possess selenoenzymes to protect their brains from oxidative damage. The danger with mercury lies in its ability to create oxidative damage by sequestering and inhibiting selenoenzyme activities; however, the majority of ocean fish (especially those most commonly eaten in the U.S.) have a much higher proportion of selenium to mercury. This larger proportion of selenium acts to replace the selenium sequestered by mercury and maintains normal selenoenzyme activities, thus preventing oxidative brain damage and other adverse consequences of mercury toxicity.

In an effort to provide some framework and guidelines for fish consumption, researchers at the University of North Dakota have developed a chart that details selenium to mercury ratios. The Selenium Health Benefit Value scale rates seafood based on the quantity of selenium relative to mercury content. The higher the SHBV of a fish, the greater amount of protective selenium it has in relation to mercury (blue indicates selenium, red indicates mercury):

SHBV scale

Eat More Omega-3

The growing research that points to the widely beneficial effects of omega-3 fatty acids in the diet, illustrates that its not only prudent but necessary to include more sources of omega-3 fats which can be obtained via whole food sources such as cold-water fish (preferably wild caught), sea vegetables, and shellfish. Some other sources include walnuts, flaxseed and leaf plants, however, these forms are comprised of alpha-linoleic acid, of which only a very small percentage actually gets converted to the vitally important DHA in the body. Another option for individuals seeking a practical and alternative form is to supplement with omega-3. They key with supplementation is to find a source that is rich in both EPA and DHA be it in pill or liquid form. Personally I prefer and recommend to clients the line of Vital Choice omega-3 supplements derived from cold-water, wild caught salmon. Regardless of the source, its imperative to stem the tide of inflammation in the body and increasing omega-3 fats, while simultaneously decreasing omega-6 fats, will pay dividends to your health.



Ralston NV. Selenium health benefit values as seafood safety criteria. Ecohealth. 2008 Dec;5(4):442-55. Epub 2009 Apr 14.

Cott, J. Omega-3 Fatty Acids: A Paradigm Shift for Medicine? NIH presentation.

Studer, M. MD, Mattias, B. MD; Bernd, L. MD; Glass, T, MSc, Heiner, C. MD, MPH. Effect of Different Antilipidemic Agents and Diets on Mortality. Arch. Int. Med. 2005; 165:725-730.

Chih-Chiang Chiu, MD, Shih-Yo Huang, Ph.D., Winston, W. Shen, MD, Kuan-Pin Su, MD. Omega-3 Fatty Acids for Depression in Pregnancy. Am. J. Psychiatry, 160: 385, February 2003.

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