Are over-the-counter fish oil supplements safe, effective and accurate with labelling? Analysis of 10 New Zealand fish oil supplements.

AIM: Fish oil supplements are regulated in New Zealand under the Dietary Supplement Regulations (Section 42, Food Act 1981) and therefore are not subject to the same level of scrutiny and regulations as medicines. We investigated accuracy of labelling, stated health benefits of fish oil supplements sold in New Zealand, and risks relating to possible mercury content. METHOD: The amounts of omega-3 fatty acids contained per capsule were determined by an independent laboratory using gas chromatography on 10 of the most popular over-the-counter fish oil supplements sold in New Zealand and were compared with amounts stated on product labels. Information on doses recommended to achieve a specific health benefit were taken from the 10 labels as well as the company websites. These recommended doses were compared with published recommended doses identified as being effective in those health areas stipulated on the labels, based on either systematic reviews, meta-analyses and/or consensus statements. Mercury was analysed by an independent laboratory using inductively coupled plasma mass spectrometry. RESULTS: The actual amounts of EPA and DHA per capsule in 90% of the over-the-counter fish oil supplements analysed were within 10% of the amount stated on the product labels. Only one product was greater than 10% below the stated dose on the label. All products suggested benefit across heart, brain and joint health and all but two products stated a range of capsules required to achieve that health benefit (eg, 2-6 capsules). Based on the maximum number of capsules recommended (which ranged from 3-6 capsules), only three products would likely confer the dose identified as optimal for achieving a health benefit across all three health areas. Only two products recommended doses that would likely confer a health benefit both at the minimum and maximum number of capsules. More products would likely benefit brain and heart health than joint health. Mercury was not detected in any sample. CONCLUSIONS: It is reassuring that the doses of 90% of the products were accurate and that mercury was not detected in any sample; however, less than a third of the supplements would likely confer all the health benefits stated, even at the highest recommended daily doses. This paper has highlighted the ongoing challenges associated with the regulation of "health claims" associated with dietary supplements in New Zealand. Indeed, the literature on health effects is contradictory at best. Clearer definitions of the types of health statements that can be made and the research necessary to support them requires regulatory clarification.

Determining quality parameters of fish oils by means of 1H nuclear magnetic resonance, mid-infrared, and near-infrared spectroscopy in combination with multivariate statistics.

Fish oil is becoming increasingly popular as a dietary supplement as well as for its use in animal feed, which is mainly due to its high contents of the health promoting omega-3 fatty acids. However, these polyunsaturated fatty acids are highly susceptible to oxidation, which results in a decrease of the fish oil quality. This study investigated the potential of 1H NMR, FT-MIR, and FT-NIR spectroscopy in the quality assessment of fish oils. A total of 84 different fish oils, of which 22 were subjected to accelerated storage with varying temperature and light exposure, were used to develop models for predicting the peroxide value (PV), the anisidine value (AnV), and the acid value (AV). Predictions were based on comprehensive spectroscopic data in combination with Artificial Neural Networks (ANN) as well as Partial Least Squares Regression (PLSR). The best ANN model for PV was obtained from NMR data, with a predictive coefficient of determination (Q2) of 0.961 and a Root Mean Square Error of Prediction (RMSEP) of 1.5meqO2kg-1. The combined MIR/NIR data provided the most reliable ANN model for AnV (Q2=0.993; RMSEP=0.74). For AV, the ANN model based on the MIR data yielded a Q2 of 0.988 and an RMSEP of 0.43mgNaOHg-1. In most cases, the accuracy of the ANN models was superior to the respective PLSR models. Variable selection and data dimensionality reduction turned out to improve the performance of the ANN models in some cases. The application of 1H NMR, FT-MIR, and FT-NIR spectroscopy in combination with ANN can be considered very promising for a rapid, reliable, and sustainable assessment of fish oil quality.

Development of botanical and fish oil standard reference materials for fatty acids.

As part of a collaboration with the National Institutes of Health's Office of Dietary Supplements and the Food and Drug Administration's Center for Drug Evaluation and Research, the National Institute of Standards and Technology has developed Standard Reference Material (SRM) 3274 Botanical Oils Containing Omega-3 and Omega-6 Fatty Acids and SRM 3275 Omega-3 and Omega-6 Fatty Acids in Fish Oil. SRM 3274 consists of one ampoule of each of four seed oils (3274-1 Borage (Borago officinalis), 3274-2 Evening Primrose (Oenothera biennis), 3274-3 Flax (Linium usitatissimum), and 3274-4 Perilla (Perilla frutescens)), and SRM 3275 consists of two ampoules of each of three fish oils (3275-1 a concentrate high in docosahexaenoic acid, 3275-2 an anchovy oil high in docosahexaenoic acid and eicosapentaenoic acid, and 3275-3 a concentrate containing 60% long-chain omega-3 fatty acids). Each oil has certified and reference mass fraction values for up to 20 fatty acids. The fatty acid mass fraction values are based on results from analyses using gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS). These SRMs will complement other reference materials currently available with mass fractions for similar analytes and are part of a series of SRMs being developed for dietary supplements.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in fish, seafood products and fish oil in Spain.

A total of 84 samples of wild and farmed fish, cephalopods and fish oils for animal feeding, traded in Spain, were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in 2009-2012, by gas chromatography-ion trap tandem mass spectrometry (GC-MS-MS). The method was optimised for screening at moderate costs, allowing PCDD/Fs determination at 1 pg World Health Organization-toxic equivalent quantities (WHO-TEQ) g⁻¹ wet weight (w w) and dl-PCBs at 0.02 pg WHO-TEQ g⁻¹ w w. Concentrations in fish and cephalopods ranged from values below the limit of detection to 1.7 pg g⁻¹ WHO-TEQ sum PCDD/Fs and dl-PCBs, considered as safe with regard to EU legislation. Higher levels were found in cod livers (5.4-54.2) and fish oils (3.3-30.7), with one noncompliant sample in each group.

Quality analysis of commercial fish oil preparations.

BACKGROUND: Fish oil supplements have grown in popularity in recent years owing to their multiple health benefits, leading to rapid growth in the number of fish oil supplements available for consumers. When choosing a product, it is important that label claims for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are met, especially when a specific dosage is required. In this study the amounts of EPA and DHA in 16 of the top-selling liquid fish oil products from the American marketplace were analysed and compared with their label claims. Peroxide value, a measure of oxidation, was also determined, along with lipid class. RESULTS: This study found that over half of the supplements did not meet their label claims for EPA and DHA, and a quarter exceeded recommended limits for peroxide value. CONCLUSION: These results suggest that more stringent regulation is required for fish oil products.

Droplet-size distribution and stability of commercial injectable lipid emulsions containing fish oil.

PURPOSE: The droplet size of commercial fish oil-containing injectable lipid emulsions, including conformance to United States Pharmacopeia (USP) standards on fat-globule size, was investigated. METHODS: A total of 18 batches of three multichamber parenteral products containing the emulsion SMOFlipid as a component were analyzed. Samples from multiple lots of the products were evaluated to determine compliance with standards on the volume-weighted percentage of fat exceeding 0.05% (PFAT(5)) specified in USP chapter 729 to ensure the physical stability of i.v. lipid emulsions. The products were also analyzed to determine the effects of various storage times (3, 6, 9, and 12 months) and storage temperatures (25, 30, and 40 °C) on product stability. Larger-size lipid particles were quantified via single-particle optical sensing (SPOS). The emulsion's droplet-size distribution was determined via laser light scattering. RESULTS: SPOS and light-scattering analysis demonstrated mean PFAT(5) values well below USP-specified globule-size limits for all the tested products under all study conditions. In addition, emulsion aging at any storage temperature in the range studied did not result in a significant increase of PFAT(5) values, and mean droplet-size values did not change significantly during storage of up to 12 months at temperatures of 25-40 °C. CONCLUSION: PFAT(5) values were below the USP upper limits in SMOFlipid samples from multiple lots of three multichamber products after up to 12 months of storage at 25 or 30 °C or 6 months of storage at 40 °C.

Analysis of omega-3 fatty acid content of South African fish oil supplements.

INTRODUCTION: Substantial evidence describes the protective effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFA) on cardiovascular diseases as well as many other conditions. Numerous fatty acid preparations are marketed for supplementing the Western diet, which is low in n-3 fats. Since these preparations may vary in their n-3 PUFA content, we tested 45 commercially available products on the South African market for their fatty acid composition. METHOD: Forty-five commercially available n-3 fatty acid supplements were analysed using gas-liquid chromatography to determine their fatty acid content. RESULTS: More than half of the n-3 supplements available on the South African market contained ≤ 89% of the claimed content of EPA and/or DHA as stated on the product labels. To meet ISSFAL's recommendation of 500 mg EPA + DHA/day can cost consumers between R2 and R5 per person per day (R60 to R150 p/p/month). Regarding rancidity, the majority of capsules contained conjugated diene (CD) levels higher than that of vegetable oil obtained from opened containers (three months) used for domestic cooking purposes, despite the addition of vitamin E as antioxidant. CONCLUSION: Since no formal regulatory structure for dietary supplements currently exists in South Africa, consumers depend on self-regulation within the nutraceutical industry for assurance of product quality, consistency, potency and purity. Our results indicate that more than half of the n-3 fatty acid supplements on the South African market do not contain the claimed EPA and/or DHA contents as stated on product labels, and they contained CD levels higher than that in unused vegetable oils obtained from opened containers used for domestic cooking purposes.

Varying quality of fish oil capsules: fatty acids and tocopherol.

OBJECTIVES: To assess the content and composition of fatty acids and tocopherols in commercially available oil capsules, and to assay thiobarbituric acid reactive substances (TBARS) as a marker of oxidation in these oils. METHODS: Fish and seal oil capsules were analyzed for their contents of long-chain omega-3 fatty acids (DPA, EPA, and DHA), tocopherols, and malondialdehyde. RESULTS: Large variations were found in the levels of EPA (6.5-40.9%), and DHA (8.1-26.4%), α-tocopherol (117-10282 µg/g), γ-tocopherol (406-2352 µg/g) and δ-tocopherol (127-978 µg/g). The level of malondialdehyde was very low in all capsules. CONCLUSION: The tested samples of oil capsules showed large variation in quality with respect to long-chain n-3 polyunsaturated fatty acids and tocopherols. The low levels of malondialdehyde indicated a successful oxidation protection strategy.

Pharmacopeial compliance of fish oil-containing parenteral lipid emulsion mixtures: Globule size distribution (GSD) and fatty acid analyses.

Recently, the United States Pharmacopeia (USP) has established Chapter 729 with GSD limits for all lipid emulsions where the mean droplet size (MDS) must be <500 nm and the percent of fat larger than 5 microm (PFAT(5)) must be <0.05%, irrespective of the final lipid concentration. As well, the European Pharmacopeia (EP) Monograph no. 1352 specifies n3-fatty acid (FA) limits (EPA+DHA> or =45%; total n3 or T-n3> or =60%) for fish oil. We assessed compliance with USP physical and EP chemical limits of two fish oil-containing lipid emulsion mixtures. All lipid emulsions passed USP 729 limits. No samples tested had an MDS >302 nm or a PFAT(5) value >0.011%. Only one product met EP limits while the other failed. All emulsions tested were extremely fine dispersions and easily met USP 729 GSD limits. The n3-FAs profiles were lower in one, despite being labeled to contain 50% more fish oil than the other product. This latter finding suggests the n3-FA content of the fish oil source and/or the applied manufacturing processes in these products is different.

Comparisons of chemical and physical properties of catfish oils prepared from different extracting processes.

Four different catfish oil extraction processes were used to extract oil from catfish viscera: process CF1 involved a mixture of ground catfish viscera and water, no heat treatment, and centrifugation; process CF2 involved ground catfish viscera (no added water), heat treatment, and centrifugation; process CF3 involved a mixture of ground catfish viscera and water, heat treatment, and centrifugation; process CF4 involved ground catfish viscera, enzymatic hydrolysis, and centrifugation. Chemical and physical properties of the resulting of catfish oils were evaluated. The CF4 process recovered significantly higher amounts of crude oil from catfish viscera than the other 3 extraction methods. The CF4 oil contained a higher percent of free fatty acid and peroxide values than CF1, CF2, and CF3 oils. Oleic acid in catfish oil was the predominant fatty acid accounting for about 50% of total fatty acids. Weight loss of oils increased with increasing temperatures between 250 and 500 degrees C. All the catfish oil samples melted around -32 degrees C regardless of the extraction methods. The flow behavior index of all the oil samples was less than 1, which indicated that the catfish oils exhibited non-Newtonian fluid behavior. The apparent viscosity at -5 and 0 degrees C was significantly higher (P < 0.05) than those at 5, 10, 15, 20, 25, and 30 degrees C. The average magnitude of activation energy for apparent viscosity of the oil was higher for CF2 than CF1, CF3, and CF4.

Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated biphenyls and organochlorine insecticides.

Fish and seal oil dietary supplements, marketed to be rich in omega-3 fatty acids, are frequently consumed by Canadians. Samples of these supplements (n = 30) were collected in Vancouver, Canada, between 2005 and 2007. All oil supplements were analyzed for polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) and each sample was found to contain detectable residues. The highest SigmaPCB and SigmaDDT (1,1,1-trichloro-di-(4-chlorophenyl)ethane) concentrations (10400 ng/g and 3310 ng/g, respectively) were found in a shark oil sample while lowest levels were found in supplements prepared using mixed fish oils (anchovy, mackerel, and sardine) (0.711 ng SigmaPCB/g and 0.189 ng SigmaDDT/g). Mean SigmaPCB concentrations in oil supplements were 34.5, 24.2, 25.1, 95.3, 12.0, 5260, 321, and 519 ng/g in unidentified fish, mixed fish containing no salmon, mixed fish with salmon, salmon, vegetable with mixed fish, shark, menhaden (n = 1), and seal (n = 1), respectively. Maximum concentrations of the other OCs were generally observed in the seal oil. The hexachlorinated PCB congeners were the dominant contributors to SigmaPCB levels, while SigmaDDT was the greatest contributor to organochlorine levels. Intake estimates were made using maximum dosages on manufacturers' labels and results varied widely due to the large difference in residue concentrations obtained. Average SigmaPCB and SigmaDDT intakes were calculated to be 736 +/- 2840 ng/d and 304 +/- 948 ng/d, respectively.

Seasonal variation in the fatty acid composition and quality of sardine oil from Sardinops sagax caeruleus of the Gulf of California.

One of the few sources of long-chain n-3 polyunsaturated fatty acids is fish oil, but considerable variation may exist according to species and season. In this study, the fatty acid profiles of sardine oils from Sardinops sagax caeruleus of the Gulf of California, Mexico, were evaluated in three seasonal catch periods. Oil quality was also evaluated by peroxide and free acid values. The most abundant fatty acids found in the oils were palmitic acid (19.3%), oleic acid (14.3%), eicosapentaenoic acid (EPA, 20.4%), and docosahexaenoic acid (DHA, 12.2%). There was no significant difference in the composition and quality among the six reduction plants where the samples were obtained. However, a significant difference in the proportion of EPA and DHA in one of the catch seasons analyzed was observed.

The combined influence of dietary flaxseed variety, level, form, and storage conditions on egg production and composition among vitamin E-supplemented hens.

Trial 1 tested the effects of ground vs whole flaxseed at dietary levels of 5, 10, or 15% compared to a corn-soybean or fish oil control on egg production of Leghorn hens over a period of 8 wk. Dietary flaxseed decreased feed consumption, weight gain, and egg weights compared to the control diets; however, flaxseed and fish oil significantly improved egg production (88.9 and 93.0%, respectively) compared to the control (83.1%). Incorporation of linolenic acid (C18:3n-3) into the egg increased linearly as the level of dietary flaxseed increased (2.31, 4.18, or 6.83% of the yolk fatty acids for 5, 10, and 15% flaxseed diets, respectively). In Trial 1, flaxseed and fish oil significantly increased percentage white and decreased percentage yolk compared to the control treatment but had no effects on egg cholesterol. Trial 2 was a factorial design of varieties of flaxseed (brown vs golden), types (ground vs whole), levels of dietary vitamin E (27 vs 50 IU/kg), and feed storage temperatures (4 vs 21 C) fed to hens for 6 wk. Brown flaxseed significantly increased egg weight and egg production compared to the golden variety. There was no difference in whole vs ground flaxseed for measured production variables. Vitamin E (50 IU) significantly improved egg production (96.1 vs 94.3%) compared to 27 IU. Storage temperature of flaxseed did not significantly affect any production variables. In conclusion, dietary flaxseed can be safely added whole to layer diets up to 15% without any detrimental effects on hen-day egg production. Levels of 10 to 15% flaxseed yield eggs with 4 to 7% yolk n-3 fatty acids, respectively, making these eggs rich sources of n-3 fatty acids.

Coconut oil and beef tallow, but not tricaprylin, can replace menhaden oil in the diet of red drum (Sciaenops ocellatus) without adversely affecting growth or fatty acid composition.

The ability of juvenile red drum (Sciaenops ocellatus) to utilize medium-chain triglycerides (MCT) and other saturated dietary lipids was investigated in two 6-wk feeding experiments. Diets contained solvent-extracted menhaden fish meal to which menhaden fish oil (control), coconut oil, corn oil, beef tallow or various levels of MCT as tricaprylin (30, 46, 65 and 80% of total lipid) were added. Diets were fed to triplicate groups of juvenile red drum in aquaria containing brackish (6%) water. In the first feeding experiment, red drum fed the control diet had the greatest weight gains and feed efficiencies. Weight gain, but not feed was slightly, of fish fed corn oil and fish fed coconut oil was slightly (P < 0.05) lower. In the second feeding experiment, fish fed coconut oil and those fed beef tallow had significantly higher weight gains and feed efficiencies than did fish fed the control diet. Fish fed the diets containing tricaprylin at all inclusion levels in both feeding experiments had significantly lower weight gains and feed efficiencies and higher levels of beta-hydroxybutyric acid in plasma. Fish fed diets with high levels of MCT also had lower (n-3) and greater (n-6) fatty acid levels in the neutral lipid fraction of muscle tissue compared with fish fed the control diet. Coconut oil and beef tallow consistently resulted in greater liver lipid deposition but had variable effects on other tissue indices. Saturated dietary lipids had variable effects on fatty acid composition of muscle polar and neutral lipid fractions.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of n-3 PUFAs (fish oil) in enteral nutrition.

Severely ill patients in need of enteral nutrition support must obtain all essential nutrients in at least the amounts recommended for daily intake (RDA) by healthy populations. Until recently essential fatty acids have been entirely omitted from enteral solutions or included only in the form of n-6 PUFAs which are structurally important for cell membranes and play a significant role as precursors (esp. arachidonic acid, AA) of eicosanoids (prostaglandins, thromboxanes, leukotrienes). However, in the absence of n-3 PUFAs, these eicosanoids may produce exaggerated effects in acute stress responses causing immunosuppression, platelet aggregation and excessive or chronic inflammation. n-3 PUFAs act as precursors of complementary eicosanoids which counteract the exaggerated responses of AA-derived eicosanoids. Therefore, n-3 PUFAs should be part of any optimally balanced diet and must be included also in enteral solutions. Since the transformation of the n-3 parent fatty acid, alpha-linolenic acid, to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is slow and unreliable, it is necessary to provide them as preformed nutrients as they occur in fish oil. The British Nutrition Foundation recommends a daily intake of EPA and DHA in amounts corresponding to the intake of 3 to 4 g standardized fish oil. The requirements can also be covered by the weekly consumption of 2 to 3 portions of fatty fish. Preliminary clinical trials have shown certain beneficial effects of fish oil intakes in diseases associated with inflammatory reactions such as rheumatoid arthritis or inflammatory bowel disease, in conditions with impaired immune competence such as burns, post-operative situations and cyclosporine treatment after renal transplants, and in conditions with enhanced platelet aggregation such as after coronary angioplasty. While these findings must be verified in strictly controlled trials, the intake of fish oil n-3 PUFAs in a balanced ratio to n-6 PUFAs can be recommended for all patients including those in need of enteral nutrition support.

[An objective index of quality and prognostication of the storage time for cod liver oil]. / Ob'ektivnyi pokazatel' kachestva i prognozirovanie srokov khraneniia meditsinskogo treskovogo zhira

Through a series of tests an objective indicator of the degree of the cod oil oxidation-the content of aldehydes reacting with benzidine-has been established. Mathematic processing of experimental data helped determine the limits of the aldehydes content in the oil of different quality, while the maximum permissible standards were fixed following biological tests carried out by the Institute of Nutrition of the AMS of the USSR. These data and investigations into the quality of the oil during its preparation and subsequent storage under different conditions formed a background to be establishing maximum permissible content of aldehydes in the half-finished and final products. Through experiments there were found the increment of aldehydes and the fall of the A-vitamin activity over a storage period of one month in large bottles of 9 1 capacity at temperatures of 10+/-2 and 20+/-2 degrees. The available data enabled it to deduce a formula for fixing approximate storage periods for medicinal oil both on shipment from the production site and at the time of control checking of its quality. The maximum permissible content of aldehydes in the medicinal oil and the method of establishing storage time are recommended to be included into the corresponding intem of the state standards-GOST, or in the pharmacopeia.