September 19, 2019

On Fish Oil and Snake Oil

Nicholas W. White, DO


As physicians, we are constantly being bombarded with new guidelines, protocols, and studies that are often thrown out or contradicted in the next publication.  We spend our free time sifting through pseudoscience and statistical witchcraft, pulling out what we can and discarding the fluff.  With drug and supplement companies marketing directly to the consumer, 1-800-EVIL-MED commercials, and of course Dr. Google, patient access to information and misinformation alike has led to concerns about medication safety.  Many are seeking more “natural” remedies not always discussed with their providers. 

Americans spend $30 billion annually on substances not approved by the FDA to diagnose, treat, cure, or prevent any disease.  Labeling and purity standards are not enforced with the same rigor as conventional medications, leaving providers questioning the role of supplements in modern medicine.  Most likely, they do neither harm nor good, with the exception of cost and interaction potential, exposing an interesting concern: if a supplement has little chance of harm but is of questionable benefit, should it be addressed?  

Enter Fish Oil
For over a decade, fish oil has been a staple supplement for patients favoring more “natural” remedies.  The emergence of fish oil as a therapy was a result of studies noting lower incidence of CHD death among Greenland Eskimos, a population known for consuming large amounts of fish.  Subsequent investigation found that fish oils, specifically DHA+EPA, have antithrombotic and antiarrhythmic effects, reduce blood pressure and heart rate, and lower triglycerides.

The safety profile of fish oil supplements is fantastic.  Below 3g/day, 4% report nausea.  At 4g/day or more, 20% reported nausea.  The main complaint is unpleasant, “fishy” burps.  

Outcome data suggests the benefits of fish oil are realized at an intake of 250mg to 500mg EPA+DHA daily, with a steep initial response that plateaus above these levels.  Triglyceride reduction demonstrates a more linear dose-response relationship.  Standard 1g daily doses may contain anywhere from 200mg to 800mg of DHA+EPA, the same amount provided by consumption of 1-2 servings of oily fish per week.  

You read that correctly.  Standard daily fish oil supplements are no more beneficial than a diet incorporating fish in 1 or 2 meals per week.  

As a family medicine physician, I see fish oil on medication lists and in pill boxes of patients with statin-worthy cholesterol profiles and triglyceride levels far below the ever-increasing pancreatitis risk threshold.  Often these patients are unaware that fish oil may not be the cardiovascular panacea as was once thought.  Many will leave their statin at the pharmacy and head for the supplement aisle.  

Addressing supplements is challenging when time is at a premium, but it must be done.  Ask patients to bring in information they find and review it with them.  It will surprise you.  They will appreciate the validation and are more likely to follow safe and effective plans they better understand.  For patients seeking a more “natural” approach, making diet recommendations (eat fish 2x/week) always seems to be a welcomed suggestion.  Try to slip some exercise in there, too.

Nicholas White, DO is a family medicine physician at TPMG Tidewater Family Medicine.