Omega-3s: Is It an Environmental Disaster?

The HWN Team | Insider

Are Omega-3 fatty acids one of nature's wonder supplements or are we just destroying the fish and the oceans and ultimately ourselves in the quest for health?

Fish oils, which are rich in omega-3 fatty acids, could be the answer to curbing the leading cause of death worldwide: heart disease. Not only that, omega-3s are suppose to combat depression, Alzheimer’s disease, asthma, help improve cognitive skills, and even cancer, to name a few.1

Being macronutrients, the body needs fatty acids especially omega-3’s in large amounts, contrary to vitamins.  Common sources include flax and hemp seeds as well as walnuts, but fish, such as salmon, sardines and even krill are probably the most bio-active source.

The craze is driving people to eat like the Inuits, who consume lots of ‘fatty’ seafood and apparently don’t suffer from heart attacks or even depression. "People have never eaten as much fish, and more people than ever are employed in or depend on the sector," according to a 2009 United Nations Food and Agriculture Organization statement.2

And for those who prefer fish oil capsules, omega-3’s have become one of the most popular nutritional supplements. The global market for omega-3 supplements was estimated to be 703 million in 2007 and continues to grow annually at about 30%. 

So, what's the proof?

Most scientists are convinced that omega -3’s benefit heart disease. A recent meta-analysis involving over 30,000 patients shows that fish oil supplements can reduce deaths due to cardiac diseases although had no effect on arrhythmias or all causes of mortality.” Probably this occurs because omega- 3 fatty acids reduce triglyceride (fatty substances) as well as ‘bad’ cholesterol (LDL). Moreover, by limiting blood clot buildup, fatty acids may actually play a role in decreasing the incidence of angina and the dreaded heart attack.

According to The Natural Medicines Comprehensive Database, fish oils have "Effective and "Likely effective ratings for hypertriglyceridemia (high triglyceride levels) and for heart disease. To achieve the "Effective and "Likely Effective ratings,  "a very high level of reliable clinical evidence supporting its use for a specific indication has been met.3

Evidence regarding their benefit on hypertensive patients also appears positive. A 20-year study (from 1985 to 2005) of more than 4000 males revealed a negative association between fish intake and the risk of hypertension.4

However fish oils are rated as only "Possibly effective for hypertension by the Natural Medicines Comprehensive database. "Possibly Effective rating is given to products which have some clinical evidence which may be "limited by quantity, quality, or contradictory findings. And, there are some studies that report no significant effects of omega-3 fat supplementation.  

But, with regard to the other disorders, results are mixed!

A meta-analysis of 23 trials demonstrated that although omega-3s lowered triglycerides and VLDL (very low density lipoprotein) cholesterol in type 2 diabetics, which is a good thing, they may raise LDL (low density lipoprotein) cholesterol. One is not better than the other but LDL cholesterol is ‘bad’ enough because it promotes cardiovascular risks.5

Since the so-called eicosanoids from the omega-3 fatty acids have anti-inflammatory properties, (in contrast to those derived from omega-6 fatty acids), increasing the amount of fish oil in the diet may benefit chronic diseases involving inflammatory processes such as arthritis, inflammatory bowel disease (IBD), atopic dermatitis and many more. However, a review in the journal, Inflammatory Bowel Disease, concluded that existing data cannot support the use of omega-3-fatty acids "for maintenance of remission in Crohn's disease and ulcerative colitis.6

As for allergies, a review in Clinical Review of Allergy and Immunology reported that fish intake during pregnancy, during lactation and during infancy may have a protective effect against allergies but results are inconsistent and if provision of protection is detected, it is unclear whether it persists for a long time.7

A review in Alternative Therapies in Health and Medicine which considered 16 clinical trials including a meta-analysis concluded that high quality research is needed to recommend omega-3-fatty acid supplements alone for osteoarthritis or for reducing  "nonsteroidal antiinflammatory drug or steroid usage in the case of rheumatoid arthritis.8

Omega-3s have also been considered for patients with intermittent claudication (a disease characterized by limping, weakness and cramps in the legs).  People suffering from chronic atherosclerosis with claudication have high blood viscosity (thickness, resistance to flow) so that there is poor blood flow in the legs and buttocks.  This is partly due to high levels of fibrinogen (a protein essential to blood clotting). A review published inthe Cochrane Database in 2007 concluded that "Omega-3 fatty acids appear to have limited haematological benefits in people with intermittent claudication. Moreover, "supplementation may also cause adverse effects such as increased total and LDL cholesterol levels.9

According to Dr. Begin and colleagues who comprehensively reviewed corresponding studies in the last 20 years, the inconsistent findings on associations between omega-3’s and cognition in relation to Alzheimer’s disease and dementia are due to "differences in sample size, heterogeneity of study populations, type of population analyses (cross-sectional vs. prospective), different methods of estimating ω3 PUFA intakes, choice of tissues and lipid fractions examined, adjustments for different confounders, and the wide variety of the applied cognitive tests.10

JAMA published a large-scale study in 2010 showing that docosahexaenoic acid (DHA) (an omega-3 component) did not benefit women with post partum depression nor improve cognitive development of their infants.11

The Natural Medicines Comprehensive Database rates fish oils "Possibly effective for hypertension, stroke, osteoporosis, kidney problems and rheumatoid arthritis while they are "Possibly - and "Likely ineffective for diseases like  gingivitis, liver disease, claudication, migraine, breast pain, skin rashes, stomach ulcers, diabetes 2 and many more.  Under "Insufficient evidence  a whole lot of indications are listed including Alzheimer’s disease, cancer, Crohn's disease and allergies.

And don't forget the following

The Institute of Medicine at the National Academy of Sciences cited research showing increased risk of bleeding and hemorrhagic stroke in a few studies following supplementation with omega-3s. Individuals who have disorders involving bleeding, who bruise very easily, or who are taking blood thinners should consult with a medical practitioner before taking supplemental omega-3 fatty acids.” The use of omega 3's in hypoglycemics has also been questioned.

OK, it sounds like we should be taking Omega- 3’s to combat heart disease. So, what’s the catch?

Fatty fish such as salmon occupy a high position in the food chain so that some toxic materials such as dioxins, mercury and PCBs may be found in high levels via bioaccumulation. Both wild and farmed salmon pose that same problem. However, reports say that that carcinogens and pesticide levels in farmed salmon are higher than in wild fish aside from farmed salmon having "two to three times fewer omega-3's than their wild counterparts.12

Furthermore, there are apparently other health contaminants in farmed salmon. Canthaxanthins are added to feeds of farmed salmon in order for them to get the nice pink color that naturally raised salmon have. In other words, their skins are dyed like shoes. This is not the worst chemical synthetic introduced to salmon.

Additionally, farmed salmon receive a lot of antibiotics which contribute to the growth of drug-resistant bacteria in humans who consume them. As with livestock, farmed salmon are administered the same antibiotics used to treat humans, a practice condemned by the World Health Organization for contributing to worldwide antibiotic resistance. There is also evidence that Pacific NorthWest farmed salmon, which are fed primarily a soy-based diet, are more omega–6’s (inflammatory) than the omega-3 wild salmon.

To add insult to injury, even fish oil capsules may not be free of contaminants. Cancer-causing chemicals have been found in ten brands of fish oil capsules. For example, "some supplements come with labels saying PCBs have been removed and yet they were found to contain PCBs when  tested by some environmentalists.13

And in the zeal to promote health, the riches of the oceans and the environment are also being threatened! 

Not only are salmon and sardines being depleted but even other fish like the menhadens. Little do we know about these fish but they are important links in the Chesapeake the Bay food chain, in that they eat off algae and "prevent oxygen-depleting algal blooms that lead to underwater dead zones.  In fact, fish oil companies are banned in some American waters.14,15

The booming aquaculture industry isn’t helping either! As an example, farmed salmon are raised in open cages which discharge waste into the ocean thus spoiling marine waters and spreading diseases. "The excreta of some large farms are equal to a sewaage from a city of 10,000 people.  Sometimes salmon escape from the farms into the open waters and when they do, they compete with wild salmon, the latter being less likely to win the competition.  

Additionally, salmon farmers are granted licenses to kill salmon predators like seals and sea lions so that in British Columbia salmon farmers may have killed "at least 5,000 Seals and Sea lions in the last decade. The real figure could be much higher as some kills, according to fish farm employees, go unreported.16

Increasing demand is also driving companies like Aqua Bounty to perform genetic manipulation of salmon in order to "help address that need by producing more fish in less time compared to current salmon farming techniques." By the way, the U.S. FDA believes that traditional and genetically manipulated salmon are biologically similar.17,18

The Bottom Line

So far, the main concern is contaminants. Try to pick the least polluted fish, go wild and consider moving to Hawaii. And if you think of supplementing, find a NSF labeled product that has been rigorously tested for contaminants.

And let’s stop exaggerating. Omega3’s are not a panacea for other disorders. At this juncture, fish oils and omega-3's appear to provide cardiovascular benefits, but that’s it!  Or are we just destroying the fish and the oceans and ultimately ourselves in the quest for health?

It'sYourCall: Best Omega3s...LabDoor

Published November 9, 2011, Updated April 14, 2014


  1. FastStats: Leading Causes of Death, CDC
  2. Global fish consumption at record high, CBC News Canada, January 2011
  3. Natural Medicines Comprehensive Database
  4. Xun P, Fish oil, selenium and mercury in relation to incidence of hypertension:  20-year follow-up study,  J. Intern Med. 2010 Dec 10
  5. Hartweg J, Omega-3 polyunsaturated fatty acids (PUFA) for type 2 diabetes mellitus, Cochrane Database of Systematic Reviews 2008
  6. Turner D, Maintenance of remission in inflammatory bowel disease using omega-3 fatty acids (fish oil): a systematic review and meta-analyses,  Inflamm Bowel Dis. 2011 Jan 17(1):336-45
  7. Kremmyda LS, Atopy Risk in Infants and Children in Relation to Early Exposure to Fish, Oily Fish, or Long-Chain Omega-3 Fatty Acids: A Systematic Review, Clin Rev Allergy Immunol, 2009 Dec 9
  8. Rosenbaum CC, Antioxidants and anti-inflammatory dietary supplements for osteoarthritis and rheumatoid arthritis, Altern Ther Health Med,2010 Mar-Apr 16(2):32-40
  9. Sommerfield T, Omega-3 fatty acids for intermittent claudication, Cochrane Database Syst Rev, 2007 Oct 17;(4)
  10. Montmayeur JP, le Coutre J, editors, What Is the Link between Docosahexaenoic Acid, Cognitive Impairment, and Alzheimer’s Disease in the Elderly?  Fat Detection: Taste, Texture, and Post Ingestive Effects. Boca Raton (FL): CRC Press:2010
  11. Makrides M. et al, Effect of DHA supplementation during pregnancy on maternal depression and neurodevelopment of young children: a randomized controlled trial, JAMA 2010 Oct 20;304(15):1675-83
  12. Jans Nick, Farmed salmon can't beat wild, USA Today, 10/2002
  13. Pollutants found in fish oil capsules, April 2002, BBC News Health
  14. Leamy E, Lawsuit raises fish oil supplement concerns, March 2010, ABC news
  15. Padgett T, The Trouble with Fish Oil, January 2010, Time
  16. Farmed Salmon Facts,
  17. Melik J, Is GM salmon swimming against the tide?  BBC News Business, September 2010
  18. Benson J, California to mandate labeling for GMO salmon,  May 2011

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