A Multi-Year Rancidity Analysis of 72 Marine and Microalgal Oil Omega-3 Supplements

Abstract

There exists significant heterogeneity in the ‘freshness’ of consumer marine- and plant-derived omega-3 (Ω3) supplements. Fears of rancidity, or the oxidation of consumer Ω3 supplements, has been debated in the literature with several prior authors reporting contradictory findings. We report the peroxide value (PV), para-anisidine value (p-AV) and total oxidation values (TOTOX) associated with 72 consumer Ω3 supplements sold in the United States sampled from 2014–2020. The effect of flavoring on the oxidation of the supplements was examined in an adjusted fixed effects model controlling for type of delivery system (enteric, liquid, animal- and vegetable-derived gelatin softgel, spray), source (algae, calamari, fish, krill, mussels), and certifications assigned by third-party organizations (e.g. USP). Overall, our results revealed that 68% (23/34) of flavored and 13% (5/38) unflavored consumer Ω3 supplements exceeded the TOTOX upper limit set by the Global Organization for EPA and DHA (GOED) voluntary monograph standard of ≤ 26, with 65% (22/34) flavored supplements and 32% (12/38) unflavored supplements failing the PV upper limit of ≤ 5 and 62% (21/34) flavored supplements exceeding the p-AV upper limit of ≤ 20. “Our findings show flavorings can dramatically alter the reported oxidation of consumer fish oil supplements such that products containing such additives are not currently indicated for the testing of secondary oxidation determined by the p-AV.” To our knowledge, no prior authors have modeled the impact of flavoring on oxidative status in 72 marine- and plant-derived Ω3 products sold in the U.S. We present our findings in this context and discuss the clinical implications related to the consumption of oxidized consumer fish oils and their effects on human health.

Keywords:

• Fish oil
• omega-3 fatty acids
• plant
• enteric
• antioxidant
• dietary supplement
• nutraceutical
• multivitamin

Authors’ contributions

Jacob M. Hands (JMH) wrote and drafted this manuscript in partnership with Dr. Mark L. Anderson (MLA), Dr. Tod Cooperman (TC), and Dr. Leigh A. Frame (LAF). MA, TC, and LAF reviewed the manuscript extensively and contributed to its design. JMH drafted the statistics. MA and TC approved, designed and contributed to the intellectual outline of this piece from statistical outline to conceptual overview.

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This manuscript was prepared without any outside financial assistance. All data was generously provided by ConsumerLab LLC. Note: ConsumerLab does not create, manufacture or invest in supplements.

Notes on contributors

Jacob M. Hands

Jacob M. Hands is a medical student at the George Washington University School of Medicine and Health Sciences. Mr. Hands worked as a clinical research associate, contract research assistant to various companies, and continues to be an active member of the NLA and other affiliates.

Mark L. Anderson

Dr. Mark L. Anderson is the Vice President for Research at ConsumerLab.com. Dr. Anderson has over 28 years of experience in dietary supplement research in addition to 10 years of experience in pharmaceutical and biotechnology drug development. He has been actively involved in analytical testing, utilizing methods such as HPLC, ELISA, CPC, GC, GC/MS, SEC, IEF, LC/MS/MS and has developed and validated qualitative and quantitative assays in accordance with GLP/GMP regulations. Dr. Anderson has authored over 10 peer-reviewed publications in pharmacology and analytical chemistry and is an active member of AOAC International, serving as an elected member of the Executive Committee in the Technical Division on Reference Materials. He was previously the Director of Research & Development at Triarco Industries. Earlier in his career, Dr. Anderson held positions as Analytical Laboratory Director at Emisphere Technologies, Associate Senior Scientist at Purdue-Frederick Pharmaceutical Co, and a Clinical Laboratory Technologist in Toxicology at Metpath Laboratories. Dr. Anderson received his Ph.D. in Pharmacology/Toxicology from St. John’s University.

Tod Cooperman

Dr. Tod Cooperman is a nationally recognized and respected researcher, writer, and speaker on consumer healthcare issues and is the President of ConsumerLab.com LLC and CEO of PharmacyChecker.com LLC. Dr. Cooperman is a graduate of the Boston University School of Medicine, receiving his M.D. in 1987. He also received his Bachelor’s degree from Boston University with a major in Medical Sciences and a minor in Economics. Recognizing a lack of quality standards and oversight in the U.S. dietary supplement industry, Dr. Cooperman founded ConsumerLab.com in 1999, guiding it to become the leading independent evaluator of dietary supplements and nutritional products. Dr. Cooperman has been called as an expert witness by committees of U.S. House of Representatives and U.S. Senate to give testimony regarding the quality and regulation of dietary supplements and has been regularly invited to speak about dietary supplement quality at the National Institutes of Health.

Leigh A. Frame

Dr. Leigh Frame brings nutrition and immunity together through clinical, translational research. Her T-shaped expertise in health, wellness, science, and medicine was developed through her wide-ranging experience in biomedical research (from wet bench to clinical research) and overseeing research and education programs.

Dr. Frame is building a GW Integrative Medicine research program while directing the graduate education programs and the Office of Integrative Medicine and Health. She is also co-founder and Associate Director of the GW Resiliency & Well-being Center. Her interests include the role of the microbiome and nutrition in health, the consequences of malnutrition in obesity, vitamin D as an immune-modulatory hormone, research ethics, science communication, whole person care, resiliency, and well-being.

While working at the Johns Hopkins Center for Bariatric Surgery, Dr. Frame earned her PhD in Human Nutrition from the Johns Hopkins Bloomberg School of Public Health and received a Master of Health Science in Molecular Microbiology and Immunology from the same school. Dr. Frame earned Distinction in Biochemistry from Mary Baldwin College (now University).