The Study
Omega-3 fatty acid fish oil dietary supplements contain saturated fats and oxidized lipids that may interfere with their intended biological benefits.
This study checked three fish oil pills in a lab and found they had some bad stuff mixed in. It also saw that when the good stuff in the pills got old, it didn't work as well in a test tube. But it didn't test people, so we don't know if it affects anyone who takes them.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Many fish oil supplements you buy at the store have bad fats and spoiled oils mixed in, which might stop them from working like they should.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 55 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — if your supplement is oxidized, it may not protect your heart like you think it should.
- 2Supplements had 10–14 types of saturated fats (up to 36% of total fat), omega-3s varied from 33% to 79%, and oxidized fats exceeded safety limits.
- 3Non-oxidized omega-3s blocked LDL damage by over 95%; oxidized ones did nothing.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Biochemical and biophysical research communications
Year
2017
Authors
R. Preston Mason, S. Sherratt
Related Content
Videos (2)
Claims (10)
Eating oxidized omega-3 fatty acids causes more harm to health than it provides benefit.
Omega-3 fatty acids in dietary supplements break down chemically when exposed to air, heat, or light during production and storage.
Most omega-3 supplements on the market contain oxidized fats, less omega-3 than stated on the label, and traces of heavy metals such as mercury or lead.
Many fish oil supplements sold commercially do not contain the amount of EPA and DHA claimed on their labels, show signs of degraded fats beyond safe limits, and may contain harmful contaminants like heavy metals.
Fish oil supplements sold over the counter have more oxidized fats than prescription omega-3 products that meet international quality standards.
Fish oil supplements on the market may contain high levels of saturated fats and damaged lipids that exceed safety standards, which could reduce their effectiveness in preventing the oxidation of small dense LDL particles in laboratory tests, potentially limiting their heart health benefits.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.