Essential Fatty Acids

Feature:

In a culture that associates dietary fat with culinary coronaries and diabetes, Americans have embraced low-fat diets as a path to wellness. True, an overabundance of energy-dense fat can enlarge waistlines, but restricting dietary fat limits essential fatty acid (EFA) intake. When it comes to health, the type of fat matters.


Good Fats: Linoleic Acid (LA) and Alpha-Linolenic Acid (ALA).

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are minimally synthesized from alpha linolenic acid and are therefore conditionally essential. Omega-3’s like ALA, EPA and DHA are “healthy” fats because consuming them reduces triglycerides, blood pressure, low- density lipoprotein (LDL) levels, inflammation, depression and cancer risk (Deckelbaum & Torrejon 2012; de Lorgeril & Salen 2012).

The heart benefits of essential fatty acids are well established, although a recent review of 20 clinical trials with more than 70,000 patients suggested omega 3’s didn’t curb heart attacks, strokes or heart disease deaths (Rizos et al. 2012). Similarly, omega-3 supplementation didn’t reduce cardiovascular events in patients with type II diabetes (ORIGIN Trial Investigators 2012) or those with a heart disease history (Kwak et al. 2012). Nevertheless, the American Heart Association continues to recommend 8 ounces of omega 3-rich fish each week, which provides about 500 milligrams of DHA and EPA (AHA 2010).

Vegans and athletes consuming low-fat diets are at risk for essential fatty acid deficiency and should make sure they are eating healthy fats (ADA et al. 2009). As an ergogenic aid, omega- 3 supplementation does not reduce post-exercise inflammation (Nieman et al. 2009) but it may improve oxygen delivery during exercise (Walser & Stebbins 2008).

The Essentials of Essential Fats

Linoleic acid: Required for growth, skin and reproduction, this omega- 6 is in all cell membranes, neurons and brain tissue, and is used to make arachidonic acid and eicosanoids that initiate vasoconstriction, platelet aggregation and pro-inflammatory processes. Good sources of linoleic acid include almonds, peanuts and the oils from olives, sunflowers, safflowers, corn and soybeans. The AHA supports an omega-6 intake of at least 5% to 10% of energy (Harris et al. 2009). The Mediterranean diet, packed with healthy olive oil, tree nuts, vegetables and fish, was recently shown to reduce major cardiovascular events in high-risk adults (Estruch 2013).

Alpha-linolenic acid: This omega-3 is a component of all cell membranes and is found in high concentrations within the brain and neurons. Omega-3’s give rise to eicosanoids that reduce inflammation, blood pressure and platelet clotting. Walnuts, kale, spinach, Brussels sprouts, flaxseeds, canola and soybeans are good sources.

EPA and DHA: Found primarily in fatty fish like salmon, herring and anchovies, DHA is structural component of the brain and retina that is required for proper fetal and infant brain and eye development. In adults, DHA improves visual acuity (Stough et al. 2011). EPA is a precursor to eicosanoids that reduce blood pressure, platelet aggregation and inflammation. Both DHA and EPA reduce cardiovascular disease markers (Deckelbaum & Torrejon 2012). The FDA recommends a daily intake of no more than 2 grams from supplements and 3 grams from food.

When it comes to wellness, healthy fats are truly essential.

References

ADA (American Dietetic Association) et al. 2009. American College of Sports Medicine position stand. Nutrition and athletic performance. Medicine & Science in Sports & Exercise, 41 (3), 709-731.

AHA (American Heart Association) 2010. Fish and Omega-3 Fatty Acids. www.heart.org/ HEARTORG/GettingHealthy/NutritionCenter/HealthyDietGoals/Fish-and-Omega-3-Fatty- Acids_UCM_303248_Article.jsp; retrieved March 10, 2013.

Hursel R., et al. 2011. The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis. Obesity Reviews, 12 (7), e573-e581.

Deckelbaum, R.J., & Torrejon, C. 2012. The omega-3 fatty acid nutritional landscape: health benefits and sources. Journal of Nutrition, 142 (3), 587S-591S

De Lorgeril, M., & Salen, P. 2012. New insights to the health effects of dietary saturated and omega-6 and omega-3 polyunsaturated fatty acids, BMC Medicine,10:50.

Estruch, R., et al. 2013. Primary prevention of cardiovascular disease with a Mediterranean Diet. New England Journal of Medicine, 368 (14), 1,279-1,290.

Harris, W.S., et al. 2009. Omega-6 fatty acids and risk for cardiovascular disease: a science advisory from the American Heart Association Nutrition Subcommittee of the Council on Nutrition, Physical Activity, and Metabolism; Council on Cardiovascular Nursing; and Council on Epidemiology and Prevention. Circulation, 119, (6), 902-907.

Kwak, S.M., et al. 2012. Efficacy of omega-3 fatty acid supplements (eicosapentaenoic acids and docosahexaenoic acid) in the secondary prevention of cardiovascular disease: a meta- analysis of randomized, double-blind, placebo-controlled trials. Archives of Internal Medicine, 172 (9), 686-694.

Nieman, D.C., et al. 2009. N-3 polyunsaturated fatty acids do not alter immune and inflammation measures in endurance athletes. International Journal of Sports Nutrition, Exercise and Metabolism, 19 (5), 536-546.

ORIGIN Trial Investigators. 2012. N-3 fatty acids and cardiovascular outcomes in patients with dysglycemia. New England Journal of Medicine, 367, (4), 309-318.

Rizos, E.C., et al. 2012. Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. Journal of the American Medical Association, 308 (10), 1,024-1,033.

Stough, C., et al 2012. The effects of 90-day supplementation with the omega-3 essential fatty acid docosahexaenoic acid (DHA) on cognitive function and visual acuity in a healthy aging population. Neurobiology of Aging, 33, (4), 824e1-824e3.

Walser, B., & Stebbins, C.L. 2008. Omega-3 fatty acid supplementation enhances stroke volume and cardiac output during dynamic exercise. European Journal of Applied Physiology, 104 (3), 455-461

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Martina Cartwright is a registered dietitian (R.D.) with a Ph.D. in Nutritional Science and Biomolec... more less
May 2013

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