Fuel your life with the purest vitamins
Nov 3rd 2025
The Case of the Fishy Fish Oil/Heart Disease Studies
. . . flawed studies suggest fish oil is ineffective in treating heart disease
It’s become an all-too familiar story. Studies of healthy populations find that a natural substance, let’s call it “substance X,” provides protection against one or more diseases. A significant body of research accumulates validating substance X’s health benefits. It becomes popular with the public, and even doctors begin prescribing it. Sales boom. But then studies begin to appear in prestigious medical journals saying substance X is ineffective and may even be dangerous. The media jump on the story like flies to a sticky bun, and the public is led to believe that none of the so-called experts really knows what they’re talking about. A confused public gives up on being proactive about their health and simply waits to get sick. When they do, they are scared enough to suspend critical judgment and blindly trust their doctor and his or her expertise in administering pharmaceutical drugs.
All of this serves the interests of the drug industry, but it severely undermines individual and collective health and drives our healthcare costs up into the stratosphere.
The latest natural substance to fall prey to such a scenario is fish oil. Based on 40 years of solid scientific research, fish oil supplement sales reached $1 billion in the US in 2010. Sales were especially supported by evidence that fish oil prevented and treated heart disease through multiple mechanisms. Fish oil has been shown to “thin the blood” – making it less likely to form dangerous clots; to moderately lower bad cholesterol and raise the good, and to significantly lower triglycerides; to lower blood pressure; to prevent and normalize irregular heartbeat; and to improve the flexibility and health of blood vessels, helping to prevent fatty deposits and fibrosis causing atherosclerosis. As I’ve written about elsewhere (see “Heart Disease” and “The Cholesterol Myth” on the Beyond Health website), the fundamental cause of heart disease is inflammation, and fish oil powerfully helps to reduce inflammation.
But three studies published last year in prestigious medical journals concluded that fish oil supplements are ineffective in preventing cardiac deaths in heart patients. In May of 2012, the Archives of Internal Medicine published a meta-analysis of previous studies on using fish oil supplements to prevent cardiac events in people with already existing heart disease. In July, the New England Journal of Medicine published a study on using fish oil supplements to prevent cardiac events in people with both heart disease and poor blood glucose control (diabetes and pre-diabetic conditions). In September, the Journal of the American Medical Association published another meta-analysis of studies on the relationship between fish oil and heart disease mortality. In the wake of these three studies, headlines such as “Fish Oil No Lifesaver,” “Fish Oil Delivers Few Heart Benefits,” and “Fish Oil Supplements Don’t Prevent Heart Attacks” began to litter the landscape.
The three studies have been criticized by Harvard researchers Frank B. Hu, MD, PhD and JoAnn E. Manson, MD, DrPH and others for methodological flaws. The patients involved were high-risk heart patients taking multiple drugs, which makes it hard to draw firm conclusions, and many of the studies included in the metaanalyses were short-term. However the fundamental error I see in these studies and some of the critiques made of them is that fish oil is seen as a drug – a magic bullet that either can or cannot “fix” the heart. Fish oil cannot be properly evaluated in this way. The true life-saving value of fish oil is that it addresses a widespread nutritional deficiency.
Fish oil (like flax oil) is rich in omega-3 fatty acids, and up to 90% of our population may be deficient in omega-3 fatty acids! The significance of this deficiency in our current epidemic of chronic disease, including heart disease, is staggering. Omega-3 fatty acids are vital to the health of every cell in our bodies, including those in our cardiovascular system. The heart itself is 60% fat, and the largest components of this fat are the essential fatty acids (EFAs) omega-3 and omega-6. (“Essential” refers to the fact that our bodies cannot manufacture them; we must ingest them.)
Whereas Americans get plenty of omega-6 fatty acids, the vast majority is deficient in omega- 3s. As explained more fully in my article, “The Oil Crisis” (found on the Beyond Health website), healthy cell chemistry requires both the 6s and the 3s, AND that they be present in the correct balance of approximately 1:1 (the current ratio is more like 20:1, and in many people as much as 50:1). The 6s tend to be proinflammatory, whereas the 3s are anti-inflammatory. Heart disease has become an epidemic primarily because of the inflammatory modern diet, and this unfavorable ratio is a significant factor in that diet.
Another problem with these studies was that the quality of the fish oil supplements involved is highly questionable. Supplement quality has everything to do with effectiveness and safety. For a long time I advised against using fish oil supplements because all of the ones I tested were rancid. Rancid oil is detrimental rather than beneficial to the body. The oils in fish oil are extremely delicate and have to be handled just right in order to prevent rancidity. These precautions have been taken for the Fish Oil Formula and the cod liver oil we carry at Beyond Health, but such care is the exception, not the rule. It is also extremely important that anyone taking fish oil take vitamin E too, since vitamin E protects the oil from becoming rancid inside the body. Whether patients in these studies were advised to take vitamin E is unknown, but chances are good they were not.
Unfortunately doctors who once prescribed fish oil are backing away from it as a result of uncertainties created by these new studies. But since heart disease is almost always in part caused by omega-3 deficiency, if you have heart disease, it is imperative to correct this deficiency in order to get well. Fish and flax oil should be used not as magic bullets but as part of a complete health-building program including an anti-inflammatory diet (The Big Four – sugar, wheat, processed oils and dairy/ excess animal protein are ALL inflammatory), plus antioxidant nutrients like vitamins C and E, CoQ10, curcumin and quercitin. The B vitamins, especially B6, B12 and folate, should be taken to reduce homocysteine, and magnesium (75% of Americans are deficient in magnesium) to normalize heart rhythms and reduce inflammation. Vitamins D and K must be taken with calcium so that the calcium is directed towards the bones and not the arteries.
Almost everyone is deficient in omega-3 fatty acids and would do well to supplement with high-quality fish and flax oils (Udo’s Choice is our recommended source of flax oil). Some people have difficulty converting the omega-3s found in flax oil into EPA and DHA, which are found in fish oil. Therefore I recommend taking both; I take a teaspoon of cod liver oil and a tablespoon of Udo’s Choice daily, and it’s what I recommend for most people. Those with diabetes, congestive heart failure or chronic recurrent angina need to be cautious about supplementing with omega-3s and should do so under supervision.