Heart disease is the leading cause of death in the United States for both men and women. About 610,000 Americans die of heart disease each year: that’s one in every four deaths. In 2007-10, about 50 percent of adults of normal weight, and almost three-fourths of those who were overweight or obese had at least one cardiometabolic risk factor (i.e., high blood pressure, abnormal blood lipids, smoking, or diabetes). Preventable factors that contribute to heart disease include smoking, lack of exercise, and eating an unhealthy diet.¹

Not All Fats Are Created Equal

One way to keep your heart healthy is to eat the right types of fat. The United States Dietary Guidelines recommend that 20-35 percent of daily calorie intake should come from fat.

There are three types of dietary fat: unsaturated fat, saturated fat, and trans fat. The American Heart Association suggests that less than 7 percent of total daily fat should be of the saturated variety, and trans fats should constitute less than one percent or be completely eliminated.

The remaining fat in your daily diet should be unsaturated fat, which can be broken down into two categories: monounsaturated and polyunsaturated. Roughly 10-20 percent of calories should come from monounsaturated fats such as olive oil, canola oil, nuts, and avocadoes. Your remaining fat intake (up to 10 percent) should be polyunsaturated fats. Essential fatty acids—known as omega-3s and omega-6s—are polyunsaturated fats, and are considered essential because the body cannot produce them; they must be consumed.

There are three main types of omega-3 fatty acids: Alpha-Linolenic Acid (ALA), Eicosapentaenoic Acid (EPA), and Docosohexaenoic Acid (DHA). While less is known about the health benefits of ALAs—a small percentage of which gets converted by your body into EPA and DHA—the research on the benefits of consuming omega-3s is clear.²

Developmental building blocks

Omega-3s provide several health benefits including mediating inflammatory responses, regulating blood coagulation, impacting cell membrane flexibility, and controlling gene regulation by influencing what genes are turned on or off. DHA is present in most cells of the body but is concentrated in the cells of the brain, heart, and retinas. Omega-3s are critical for developing infants and children, helping them to maintain visual acuity, contribute to neurological development, and build muscle and tissues.³ These “building blocks” also make it important for pregnant women to consume omega-3s, to help ensure the proper gestational age for their growing baby.

Omega-3s and Heart Health

The nearly 56 percent of American adults that have been diagnosed with either pre-hypertension or hypertension defined as having elevated blood pressure equivalent or greater than 140/90—should be particularly advised on the benefits of omega-3s. An abundance of research shows that omega-3s are cardioprotective nutrients. Higher blood levels of EPA are associated with a decreased risk of mortality from coronary heart disease (CHD) and sudden cardiac death. A recent meta-analysis of randomized-controlled studies found that daily dosages greater than 1,000 mg EPA + DHA reduced CHD risk by 20 percent or greater.⁴

EPA + DHA supplemented in relatively high doses—greater than 3 grams a day—have been shown to decrease triglycerides while increasing HDL, also known as the “good” cholesterol.⁵ Other studies have found EPA + DHA to improve blood vessel function, decrease inflammation, and lower blood pressure.⁶

Food-First Approach

As with any nutrient, it is ideal to get your required nutrients from food first and supplementation second. The adequate intake for ALA is 1.6 grams for men and 1.1 grams for women. ALA comes from plant sources such as flaxseeds, walnuts, chia seeds, and soybeans. And although the ALA conversion process to DHA and EPA is inefficient—less than 5 percent of consumed ALA converts to EPA and less than 1 percent to DHA—these foods have numerous, other health benefits beyond the as-yet not fully understood ALA benefits. To ensure the proper DHA + EPA consumption, fish is your best bet.

While there is no Dietary Reference Intake established for EPA + DHA, the US 2015 Dietary Guidelines for Americans recommend adults consume 8 ounces of a variety of seafood for an average of 450 - 500 mg of EPA + DHA per day, a level of omega-3s supported by the Academy of Nutrition and Dietetics, too. Good sources of omega-3 fat are cold-water fish such as salmon, sardines, herring, mackerel, black cod, and blue fish. Larger fish like shark, swordfish, king mackerel, and tilefish are also good sources of omega-3s but should be avoided by pregnant women, children, the elderly, and people with a compromised immune system, due to their mercury content. Seafood also provides a variety of vitamins including A, B-complex, and D, as well as minerals including selenium, iodine, iron, and zinc, which have various health benefits. Other food sources of omega-3s include fortified foods such as eggs, milk, juice, yogurt, and buttery spreads.²

The National Health and Nutrition Examination Survey (NHANES) 2009-10 survey found most Americans consume only a fourth of the recommended intake for EPA + DHA per day. Supplementation can be used to fill the nutrient gaps in your diet. There are three main sources of EPA + DHA supplementation: fish oil, krill oil, and algal oil. Fish oils do not increase risk for clinically significant bleeding and can be used in conjunction with anticoagulation medications such as Coumadin.⁷ If you choose fish oil, make sure it is of high quality and has been molecularly distilled to avoid contaminants like mercury. Krill oil is made from a small shrimp-like crustacean. It is just as effective as fish oil but should be avoided by those with a shellfish allergy. Algal oil is derived from marine algae and is a good source of omega-3s for vegetarians, vegans, and those looking to avoid fish.

* Omega- 3 supplementation of up to 3 grams per day is generally recognized as safe (GRAS) by the Food and Drug Administration.⁸

Oh me, oh my, omega

If you haven’t been cognizantly consuming the appropriate levels of omega-3s every day, don’t fret. As long as you’ve been eating a varied, whole foods-based diet, you may already be hitting the target for heart-healthy fat intake. For those looking to ensure that these essential fatty acids make their way into your meals, consider these easy tips:

1. Sprinkle ground flaxseed into your breakfast. Whether you’re cooking up some quick oatmeal, whipping up some Sunday pancakes, or blending up a sweet smoothie, flaxseed can boost the omega power of your morning easily and deliciously.
2. The salmon swap. Toss the tuna in your lunchtime salad for salmon like in this salmon nicoise recipe. 
3. Avocado toast. Use omega-3 fortified eggs along side heart-healthy fiber-loaded avocado for a filling scrumptious meal. For a hearty bonus use flaxseed crackers instead of toast.

For more info and tips on incorporating healthy fats into your diet, check out these additional resources.

Reference:

1. http://www.cdc.gov/heartdisease/docs/consumered_heartdisease.pdf
2. http://www.eatrightpro.org/~/media/eatrightpro%20files/practice/position%20and%20practice%20papers/position%20papers/dietary-fatty-acids-paper-.ashx
3. http://www.seafoodhealthfacts.org/compare-benefits-risk/general-information-healthcare-professionals
4. Wen YT, Dai JH, GAO Q. Effects of Omega-3 fatty acid on major cardiovascular events and mortality in patients with coronary heart disease: a meta-analysis of randomized controlled trails. Nutr Metab Cardiovasc Dis. 2014;24:470-5.
5. Eslick GD, Howe PR, Smith C, Priest R, Bensoussan A. Benefits of fish oil supplementation in hyperlipidemia: a systematic review and meta-analysis. Int J Cardiol. 2009;136:4-16
6. Miller PE, Van Elswyk M, Alexander DD. Long-chain omega-3 fatty acids eicosapentaenoic acid and docosahxaenoic acid and blood pressure: a meta-analysis of randomized controlled trails. AM J Hyperten. 2014;27:885-96
7. Wachira JK, Larson MK, Harris WS. N-3 Fatty acids affect haemostasis but do not increase the risk of bleeding:clinical observations and mechanistic insights. Br J Nutr. 2014;111:1652-62 [Pub Med] 
8. US Department of Health and Human Services, Food and Drug Administration. 21 CFR part 184 [docket no. 86G0289]. June 5, 1997.