Fish Oil is Dead… or Is It?

If you’re a patient or a regular reader of my articles, you know that one supplement that I often recommend is fish oil — a good source of omega-3 fatty acids.  These fats are essential to our health, because our bodies cannot make them from any other type of fat.  The many benefits of omega-3 fats include:

  • Cardiovascular health benefits
  • Immunomodulation
  • Anti-inflammatory effects
  • Psychological and behavioral health improvement
  • Improved bone density
A large study published recently in the New England Journal of Medicine (1) has called into serious question the well-established cardiovascular benefits of fish oil.  Italian researchers divided a group of over 12,000 subjects into two groups:  one received 1 gram of omega-3 fats from fish oil per day, the other 1 gram of placebo (olive oil).  These were high-risk patients:  people with multiple cardiovascular risk factors such as high cholesterol, type 2 diabetes, or even established atherosclerosis.  The outcome?  After 1 year, there was no difference in the rates of death, non-fatal heart attack, or stroke between the two groups.
What are we to conclude from this?  The sound-bite headlines trumpet “Fish Oil is Worthless!”  Some eminent cardiologists agree.  But let’s peel back the layers, and examine the flaws in this otherwise large and impressive study.
  1.  Dose.  1 gram of omega-3 fats is not a high dose at all, especially in this population of high-risk patients.  For my patients with any cardiovascular risk factors, I recommend 1.5-2.5 grams of omega-3 fats per day.  And remember, a 1 gram (1000 mg) fish oil softgel only contains about 300 mg of omega-3s.  For cardiovascular health, 5-8 softgels per day are required.  An alternative would be to take a concentrated form of fish oil, or to use liquid cod liver oil.  I take about 2 teaspoons of cod liver oil daily, which supplies around 2.5 grams (2500 mg) of omega-3s.
  2. Quality.  There is a wide variability in the quality of fish oil products.  A pharmaceutical-grade form is best, which is screened for impurities, and has less chance of being rancid.  The form used in the study is not specified.
  3. Lab Values.  One of the main ways that omega-3 fats benefit the cardiovascular system is by lowering triglyceride levels — data about patients’ triglyceride levels were not included in the study.  Also, how well were the diabetic patients maintaining blood sugar control?  Poorly controlled blood sugar is a major risk factor that a little fish oil won’t overcome.
  4. Choice of “Placebo.”  A placebo (inactive pill) is necessary in research studies to compare to the active intervention, to account for the fact that people’s expectations about receiving care can have a strong therapeutic effect.  This is know as the placebo effect.  But is olive oil a good choice as an inert comparison?  There is a mountain of research about the cardiovascular benefits of the Mediterranean Diet, whose foundation is daily olive oil use.  Just a few weeks ago, I wrote about the PREDIMED study, which found that an olive oil-supplemented Mediterranean diet resulted in a 30 percent decreased risk of cardiovascular disease
  5. Other Benefits of Omega-3 Fats.  Now granted, the list of other benefits was not being looked at in this study, but some commentators really threw the baby out with the bathwater on this point.  Cardiologist Eric Topol, MD, called fish oil a “no-go,” a “nada effect,” and even “implores” his patients to stop taking it.  Really?  That’s quite an exercise in ignoring the large body of research on fish oil for multiple body systems.
As always, I urge you to look past the headlines, and consider the whole research picture.  Don’t throw out your fish oil on the basis of this one flawed study.

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