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

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. 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.

Marked variability of monacolin levels in commercial red yeast rice products: buyer beware!

BACKGROUND: Red yeast rice (RYR) is a widely available dietary supplement used by millions of patients as an alternative therapy for hyperlipidemia. It contains 14 active compounds called monacolins that inhibit hepatic cholesterol synthesis. Although studies have suggested that some formulations of RYR may be effective and safe for lipid lowering, monacolin levels are not standardized among marketed products and are generally not published on labels. We evaluated monacolin levels in 12 commercial RYR formulations and tested for citrinin, a mycotoxin that is nephrotoxic in animals. METHODS: Each formulation of RYR was labeled "600 mg/capsule" of active product. Analyses for monacolins and citrinin were performed between August 2006 and June 2008 using high-performance liquid chromatography with mass spectroscopy-mass spectroscopy detection. Laboratory analyses of RYR products were conducted by ConsumerLab.com, White Plains, New York. RESULTS: There was marked variability in the 12 RYR products in total monacolins (0.31-11.15 mg/capsule), monacolin K (lovastatin) (0.10-10.09 mg/capsule), and monacolin KA (0.00-2.30 mg/capsule). Four products had elevated levels of citrinin. CONCLUSIONS: We found striking variability in monacolin content in 12 proprietary RYR products and the presence of citrinin in one-third of the formulations tested. Although RYR may have potential as an alternative lipid-lowering agent, our findings suggest the need for improved standardization of RYR products and product labeling. Until this occurs, physicians should be cautious in recommending RYR to their patients for the treatment of hyperlipidemia and primary and secondary prevention of cardiovascular disease.