Nutrition | Basics | Foods for Health | Good - Bad Food | Omega-3 | Supplements |
  Sources or Omega-3: | Salmon (farm - wild): | Recommended Intake: | About Ω-3 | Links:

Omega-3 fatty acids may be important in preventing many health problems, including heart disease, rheumatoid arthritis, and cancer. They also play a role in improving mood and sharpening memory.
According to LiveScience.com in 2016 "A study from an international consortium comprising 19 studies from 16 countries with more than 45,000 participants -- found that higher circulating blood levels of omega-3 fatty acids were associated with a 10-25% reduction of fatal heart attacks.
A 2006 report "Fish intake, contaminants, and human health: evaluating the risks and the benefits." published in JAMA said that risk of coronary death could be reduced by 36%.

Cold water fish are the highest source of EPA and DHA (see below) omega-3 fatty acids which have been shown to be very effective in reducing cardiovascular disease risk.

Sources:
Fish Portion Total
Ω-3 FA (g)
Salmon, Atlantic Farmed1 4 oz. 2.1-2.6
Mackerel, canned, drained 4 oz. 2.2
Mackerel, Atlantic 4 oz. 2.9
Mackerel, King 4 oz. 2.5
Salmon1, Atlantic Wild 4 oz. 1.6-1.9
Herring, Pacific 4 oz. 1.9
Herring, Atlantic 4 oz. 1.8
Sardines, caned in oil, drained 4 oz. 1.8
Lake Trout 4 oz. 2.2
Salmon, canned, drained 4 oz. 2.2
Herring 4 oz. 1.9
Tuna, bluefin 4 oz. 1.8
Sardines, canned in oil, drained 4 oz. 1.8
Salmon1, cold water, fresh and frozen, cooked 4 oz. 1.7
Swordfish, fresh and frozen, cooked 4 oz. 1.7
Bluefish, fresh and frozen, cooked 4 oz. 1.7
Tuna, albacore 4 oz. 1.7
Atlantic Sturgeon 4 oz. 1.7
Anchovies 4 oz. 1.6
Salmon, Sockeye 4 oz. 1.4
Salmon Chinook (King) (Pacific) 4 oz. 1.4
Herring, Fresh water 4 oz. 1.3
Trout, steelhead 4 oz. 1.2
Trout, brooke & rainbow 4 oz. 0.7
Crab, soft shell, cooked 4 oz 0.6
Smelt, rainbow 4 oz 0.5
Scallops, Maine, fresh and frozen, cooked 4 oz. 0.5
Tuna, canned in water, drained 4 oz. 0.3
Tuna, canned in oil, drained 4 oz. 0.2
Lobster, cooked 4 oz. 0.1
Nuts and Seeds Portion Total
Ω-3 FA (g)
Walnuts 1 oz. 2.6
Flax seeds 1 oz. 1.8
Pecans, dry roasted 1 oz. 0.3
Pistachios, roasted 1 oz. 0.1
Poppy seeds 1 oz. 0.1
Pumpkin seeds, shelled 1 oz. 0.1
Sesame seeds 1 oz. 0.1
Almonds, dry roasted 1 oz. 0
Oils Portion Total
Ω-3 FA (g)
Flax seed oil 1 Tbsp. 6.9
Sardine oil 1 Tbsp. 3.7
Cod liver oil 1 Tbsp. 2.8
Walnut oil 1 Tbsp. 1.4
Canola oil 1 Tbsp. 1.3
Soybean oil, unhydrogenated 1 Tbsp. 0.9
Olive oil 1 Tbsp. 0.1
Grains and Beans Portion Total
Ω-3 FA (g)
Soybeans, dried, cooked ½ cup 0.5
Tofu, regular 4 oz. 0.3
Other Portion Total
Ω-3 FA (g)
Egg Yoke 3.5 oz. 1.5
Milk Human 3.5 oz. 0.8

Sources:
Omega-3 Fatty Acids | Tufts University School of Medicine
Omega-3 Rich Fish | Reader's Digest
Omega-3 Fatty Acid Content in Fish | Oregon State - A more detailed list broken down by type of omega-3 (LNA, EPA and DHA).

Recommended Intake:
The current recommendation according to Tufts is to have 7 to 11 grams of omega-3 fatty acids each week.
The American Heart Assn. says two 3.5 oz servings per week. (More if you have high triglycerides.)
i.e 3-5 4 oz. servings of Mackerel or 4-6 4 oz. servings of Salmon.
My typical piece of salmon is 5½ oz., so at my weight (145-150 lbs) three servings of Atlantic Salmon would be enough with walnuts to snack on.

Supplements:
Fish Oil 360 mg of Omega-3 = 2.5 g/week @ 1 capsule/day
Flaxseed oil 1400 mg (700 mg Omega-3) = 5 g/week @ 1 capsule/day
See Supplements. They are not all their cracked up to be.

1. Salmon - The benefit of eating farmed salmon versus wild salmon is hotly debated.
  At "Nutrition Differences of Farmed Fish vs. Wild Fish" | Shape Magazine they say "A three-ounce serving of wild salmon contains 1.4g of long chain omega-3 fats, while the same size serving of farm-raised salmon contains 2g.
At Oregon State they say a 3.5 oz (100 g) serving of farmed atlantic salmon has 1.8g of omega-3.

  Polychlorinated biphenyls (PCBs) are another chemical toxin found in both wild and farmed salmon. Farmed salmon generally contains higher levels of PCBs. The good news is that cooking fish leads to the removal of some of the PCBs. If you eat salmon frequently (more than twice a week), then it may be worth buying some wild salmon to minimize exposure to excessive PCBs.

At Salmon Recommendations from the Seafood Watch Program they rate types of salmon. They say,
Virtually all Atlantic salmon is now farmed rather than wild-caught. Atlantic salmon farmed in closed tanks is a "Best Choice." Closed tanks often have less effluent, disease, escapes and habitat impacts than other aquaculture systems. Tip: Currently, only 0.1% of farmed Atlantic salmon is farmed in closed tanks. These sources will be labelled as "land-based" or "tank-based" salmon.

Atlantic salmon farmed in Canada, Scotland, Chile (excluding Verlasso® brand) and Norway (excluding Blue Circle® brand) is on the "Avoid" list.

About 60% of Chinook salmon is farmed. Chinook salmon caught in Alaska, farmed in New Zealand and farmed in closed tanks is a "Best Choice." In Alaska, management of salmon fisheries is highly effective. In New Zealand, the industry operates on a small scale and has few environmental impacts. Closed tanks often have less effluent, disease, escapes and habitat impacts than other aquaculture systems.

At Seafood Selector they rate Canned salmon and Wild Alaskan salmon the best.

A Jan. 2016 article in the Washington Post article Can Land-Based Fish Farms Solve Farmed Seafood Woes? | Civil Eats says,
"Recirculating aquaculture systems (RAS) on land could be a solution to many of the problems, as they can control what the fish eat, what they are exposed to, as well as their living conditions. "
"This method is energy intensive, but new systems will recycle fish waste into biogas at an onsite plant that will power the farm."


About Omega-3 (Ω-3 or n-3)

A type of polyunsaturated fatty acids (PUFAs) that must be obtained through the diet because it cannot be made by the human body.

What makes omega-3 fats special? They are an integral part of cell membranes throughout the body and affect the function of the cell receptors in these membranes. They provide the starting point for making hormones that regulate blood clotting, contraction and relaxation of artery walls, and inflammation. They also bind to receptors in cells that regulate genetic function. Likely due to these effects, omega-3 fats have been shown to help prevent heart disease and stroke, may help control lupus, eczema, and rheumatoid arthritis, and may play protective roles in cancer and other conditions.
Omega-3 Fatty Acids: An Essential Contribution | The Nutrition Source | Harvard T.H. Chan School of Public Health

The consumption of EPA plus DHA is protective at doses <1 g/day. The therapeutic effect appears to be due to suppression of fatal arrhythmias rather than stabilization of atherosclerotic plaques.
At doses >3 g/day, EPA plus DHA can improve cardiovascular disease risk factors, including decreasing plasma triacylglycerols, blood pressure, platelet aggregation, and inflammation, while improving vascular reactivity.
Source: n-3 fatty acids and cardiovascular disease. Am J Clin Nutr. 2006 Jun;83(6 Suppl):1477S-1482S, Breslow JL

There are three main omega-3s:

Structure [x:y] - x = Carbon atoms, y = cis double bonds.

  • Eicosapentaenoic acid (EPA) [20:5] and docosahexaenoic acid (DHA) [22:6] come mainly from fish, so they are sometimes called marine omega-3s.
  • Alpha-linolenic acid (α-linolenic acid, LNA or ALA) [18:3] is the most common omega-3 fatty acid in most Western diets. It is found in vegetable oils and nuts (especially walnuts), flax seeds and flaxseed oil, leafy vegetables, and some animal fat, especially in grass-fed animals. The human body generally uses ALA for energy. Between 0.5 and nine percent of ALA is converted to DHA.
Amount per 3.5 oz. serving
Type ALA
[18:3]
EPA
[20:5]
DHA
[22:6]
Total
EPA+DHA
Mackerel, Atlantic 0.1 0.9 1.6 2.5
Salmon, Atlantic Farmed 0.1 0.6 1.2 1.8
Lake trout 0.4 0.5 1.1 1.6
Bluefin Tuna 0.0 0.4 1.2 1.6
Walnuts 10.4 0.0 0.0 0.0
Source: Omega-3 Fatty Acid Content in Fish | Oregon State

Some-but not all-studies show an increase in prostate cancer and advanced prostate cancer among men with high intakes of ALA (mainly from supplements).
Source: Omega-3 Fatty Acids: An Essential Contribution | The Nutrition Source | Harvard T.H. Chan School of Public Health
See also Omega-3 ALA - overlooked and misunderstood? By Stephen Daniells, 26-Jun-2008


Links:
Omega-3 Fatty Acids | Tufts University School of Medicine
Fish intake, contaminants, and human health: evaluating the risks and the benefits. - PubMed - NCBI
Omega-3 Fatty Acids: An Essential Contribution | The Nutrition Source | Harvard T.H. Chan School of Public Health
Omega-3 Fatty Acid Content in Fish | Oregon State
Seafood Selector | Environmental Defense Fund (EDF)
Salmon Recommendations from the Seafood Watch Program

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last updated 16 July 2016