Tag Archives: omega-3 fatty acids

Nutrition Fact: Eating Fish Can Be Healthy and Sustainable!

Baked Salmon

Photo Credit: Minnesota Dept. of Health

Did you know the average American eats less than half the recommended 8 ounces/week?  Before I started studying nutrition, I must admit that I ate very little to no fish as well.  However, after just my first nutrition class several years ago, I quickly learned how essential this food is to your health and slowly trained myself to eat more fish.  And now after living in Seattle for almost 5 years, I totally love fish—well most of them at least!  Definitely helps that you can find very fresh fish here. 🙂 So I thought I’d share why fish is so important to our health and what inspired me to start eating more fish.

What are the Health Benefits of Fish? 

  1. Promotes Heart Health.  Studies show that just two servings of fish a week can reduce your risk of dying from a heart attack by 30%!  This is mainly because of the omega-3 fatty acids it contains which I wrote about in more detail earlier here. Omega-3 fatty acids from fish contain both eicosopentaenoic acid (EPA) and docoshexaenoic acid (DHA) which has been shown to decrease triglyceride levels, blood pressure, and the growth of atherosclerotic plaque, as well as increase HDL (good cholesterol)—all of which are protective against heart disease.
  2. May Reduce Cancer Risk.  Early research suggests that EPA may inhibit growth of certain cancers
  3. Great source of nutrition. Fish is a filling lean protein that is high in vitamins and minerals such as Vitamin D, Calcium, and Magnesium.

What about Contaminants? 

While fish is the BEST source of EPA and DHA in the diet which is what makes fish an essential part of a healthy diet, it’s also a major source of mercury and other potentially toxic environmental contaminants.  However, in moderation and with increased knowledge, eating the right amounts and kinds of fish actually can minimize your risk of potential contaminants while receiving the beneficial nutrients they contain.  Here’s what you need to know:

  • Mercury –  Today, most fish contain trace amounts of mercury, but a handful have especially high levels which should be avoided, especially for pregnant women and young children.  To avoid fish high in mercury, avoid consuming these fish regularly or at all: tilefish, swordfish, king mackerel, marlin, and shark.  The basic rule of thumb is the larger the fish, the longer they’ve lived in the ocean and the more plankton-eating fish containing trace amounts of mercury they’ve consumed leading to higher the levels of mercury.   Commonly eaten fish such as shrimp, canned light tuna, salmon, Pollock, and catfish are all low in mercury. 
  • PCBs- Certain rivers and lakes are exposed to this synthetic chemical carcinogen used in many industrial and commercial operations and thus contaminate our fish supply.  Look for statewide coastal advisories on PCBs to know whether or not certain fish may contain higher amounts.  The good news is that proper cooking methods can reduce your exposure.  Since most of the PCBs get stuck on the skin and excess fat, try these tips to reduce PCB’s in your seafood:
  1. Grilling or broiling is better than frying since it allows fat to drain away which is often were the most PCB’s are found. 
  2. Before cooking, remove the skin and fat from the fish      

What are Recommendations for Fish Consumption?

Serving amount Frequency
American Heart Association 3.5 ounces 2 times/week
Academy of Nutrition and Dietetics 3 ounces At least 2 times/week
For Pregnant women and young children Up to 12 ounces Per week (low mercury fish) 

How to Eat Fish Sustainably?


Photo Credit: Enric Sala, NatGeo

The other day I went to a great talk by National Geographic Explore in Residence, Dr. Enric Sala.  I had heard some of what he talked about before in terms of over fishing but he really helped explain how real the problem of overfishing is and the detrimental effects it’s having on our ocean habitats and the entire food systems and ecosystems.  He’s doing a lot of policy and advocacy work to improve the sustainability of how we fish but in the meantime, they’ve compiled a great interactive chart that lays out what we as consumers can do to eat fish that are sustainably caught and reduce demand for fish that are endangered or very unsustainably fished.  It also includes information on mercury levels and other toxins.  You can view it here.

My Recommendations:

To keep your exposure to mercury and other toxins low, promote the health of our oceans and marine environments, and still receive the health benefits fish offer, here are the best fish to consume at least 8 ounces a week:

  • Wild Alaskan Salmon
  • US Farmed Catfish 
  • Farmed or wild Bass
  • US or Central America Farmed Tilapia
  • US Farmed Rainbow Trout
  • Atlantic Herring
  • Pacific Sardines
  • Pacific Sole
  • US Mahi Mahi
  • US Pacific Cod
  • US Albacore or Yellowfin Tuna (but high in mercury so eat less than twice a week)
  • Alaskan Black Cod (but high in mercury so eat less than twice a week)


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Nutrition Fact: Not All Sources of Omega-3 Fatty Acids are Equal

You’ve all heard that omega-3 fatty acids are good for you but you may not know why and the best ways to get it so let me try to clarify a few things first.

  • Omega-3 fatty acids are a class of polyunsaturated fatty acids and α-linolenic acid is one form that is essential for metabolism but not synthesized by the body so needs to be received from diet.
  • α-linolenic acid (ALA) is converted to long-chain forms of omega-3’s, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the body.
    • The conversion from ALA to EPA is only 5-10%
    • The conversion from ALA to DHA is only 0.1-1.0%.
    • EPA and DHA omega-3 fatty acids can be directly consumed in the diet from fish and small amounts from chicken.

What are health benefits of omega-3 fatty acids?

  • The omega-3 ALA has not been shown to show the same beneficial health benefits as EPA and DHA.
  • EPA and DHA have been found to be beneficial for infant growth, neural and retinal development, heart disease protection, and some evidence of reducing risk of coronary heart disease.
  • Omega-3 fatty acids, EPA and DHA have been shown to decrease triglyceride levels, decrease growth rate of atherosclerotic plaque, and slightly lower high blood pressure.

What are sources of omega-3 fatty acids?

  • ALA is commonly found in chloroplast of green leafy veggies, flaxseeds, chia, and walnuts.  But remember, the conversion to EPA and DHA is fairly inefficient from these sources.
  • EPA and DHA is best consumed from cold water oily fish like salmon, sardines, mackerel, anchovies, and herring but is found in small amounts in most other seafoods too.

Source: Cornerstone Wellness and Rebuild Blog

Official Recommendations

Organizations Official Recommendations
Academy of Nutrition and Dietetics 2 servings of fish per week, preferable from fatty fish  (500 mg/day EPA and DHA)
National Cholesterol Education Program Fish is recommended as a food item for people to choose more often as protein
World Health Organization Regular fish consumption (1-2 servings/week; each serving should provide 200-500 mg EPA and DHA)

* 8 ounces of cooked fatty fish per week is equivalent to 500 mg/day of EPA and DHA

 Other Useful Tips to Know

  • Farmed salmon actually has more EPA and DHA than wild salmon but both are excellent sources of omega-3’s.
  • White albacore tuna has twice as much EPA and DHA as light tuna.
  • Omega-3 from foods is always better than from supplements.  One of the reasons is that often times supplements actually just contain ALA which does not have the true health benefits you want which come from EPA and DHA.  Additionally, if you get fish oil supplements, it’s difficult to determine what fish they use and also the level of mercury in the fish, especially if they extract it from the fish skin.  So unless your doctor recommended increased intake of omega-3, you can get plenty from a healthy diet.
    • If you do take supplements, the FDA recommends that consumers not exceed more than a total of 3 grams per day of EPA and DHA, with no more than 2 grams per day from dietary supplements.  (unless otherwise recommended by your doctor)
  • While Flaxseeds don’t convert to EPA and DHA as efficiently as from fish, it’s a great food that can be added easily in your diet.  Make sure you use ground flaxseed and not whole.  Ground flaxseed is also preferable to flaxseed oil because in addition to omega-3 fatty acids, the seeds contain fiber, protein, vitamins, and minerals.  Try to add about 2 tablespoons of ground flaxseed to cold and hot cereals, oatmeal, batters, yogurts, salads, milkshakes, or smoothies.  I personally add it to cereals and milkshakes to to make them more nutritious.
  • Walnuts are also good sources so try adding it to your yogurt in the mornings or blend in your milkshakes or smoothies.  Because walnuts are a soft nut, they blend really well into milkshakes and not only do they add omega-3’s, but also adds a little bit more protein.
  • Canola and soybean oil both are good sources of omega-3 so try cooking with those oils from time to time and use flaxseed or walnut oil in salad dressings.
  • If you want to find out the EPA content of various types of seafood check out the USDA website and search their database. When looking at the full nutrient profile, you can find the amount of EPA by looking at the amount listed under 20:5 (the scientific abbreviation for EPA).

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