Omega 3 supplements New Zealand and Australia: less EPA and DHA than claimed

Nearly all fish oil supplements produced in New Zealand and Australia have fewer fatty acids than stated on the 'label: only 3 out of 32 contain Omega 3s corresponding to the levels indicated. In addition, most of the products exceed the recommended oxidation level. Evidence prompting authorities to review guidelines on fish oil supplements.

This was revealed in a scientific report published in the journal Nature and carried out by researchers at the University of Auckland (New Zealand).

Fish oil: important health effects

Fish oil supplements are among the most popular dietary supplements worldwide. They contain significant amounts of omega-3 polyunsaturated fatty acids including EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Fish oil supplements have shown promising effects in reducing inflammation, improving cognitive ability, and reducing the risk of cardiovascular disease. Mega-3 fatty acids are highly prone to oxidation because of the large number of double bonds in their structure. In a poor-quality omega-3 supplement, oxidation replaces omega-3 fatty acids with lipid peroxides and secondary oxidation products. 

The addition of antioxidants alone reduces but does not prevent oxidation. The degree of oxidation can be described by measurement of several parameters that are used to estimate the total oxidation value. A number of organizations around the world have recommended maximum levels for these indices, however, these are based on palatability, as there is no clear data of health effects.

Omega-3 contents lower than those reported on labels

During the study 32 different brands of supplements, almost all produced in New Zealand and Australia, were analyzed for their Omega-3 content by gas chromatography before their expiration date. The values of peroxides and other metabolites were measured in order to calculate the degree of total oxidation. The analyses showed a discrepancy between the EPA and DHA contained in the samples and that stated on the packaging, and showed that 92 percent of the supplements exceeded the content of oxidation products. According to Ian Musgrave, a toxicologist and pharmacologist at the University of Adelaide, this last finding is very important; while a lower than expected dose of Omega-3 may not be harmful, oxidation byproducts could be, especially in supplements that greatly exceed international guideline values. 

The 'excess of oxidation products in a supplement is considered contamination, and should be taken into consideration by the Therapeutic Goods Administration (TGA), the Australian authority that regulates on drugs and medical devices while also disseminating information on regulations and safety. In this regard, it should be considered that there are currently 683 fish oil-containing products on the TGA registry, but also some containing fish oil that may be sold in Australia as food, and therefore unregulated.

Consumers may take smaller doses than they believe

According to Ken Harvey, drug policy expert and associate professor at Monash University's School of Public Health, the study reported long-standing deficiencies in the regulation of complementary medicines in Australia and New Zealand. These include some pre-market evaluations of products, limited and poorly targeted post-market surveillance, and a lack of effective provisions to deter violations of TGA regulations. 

Numerous reports over the past decade have highlighted the lack of penalties for manufacturers who lie to consumers about the contents of their items. Those who take fish oil supplements do so because they aim to achieve an anti-inflammatory effect or keep triglyceride levels low, but in reality they may be taking less effective doses, as pointed out by Peter Clifton, professor at the Baker Heart and Diabetes Institute in Melbourne. In addition, this study suggests that high amounts of oxidation products may interfere with the benefits of Omega-3s, although the long-term implications are unknown. According to the researchers, it is possible that highly oxidized fish oil may promote fatty deposits in the arteries and thus the opposite of what consumers expect from supplements.   

Source: Benjamin B. Albert, Jose G. B. Derraik, David Cameron-Smith, Paul L. Hofman, Sergey Tumanov, Silas G. Villas-Boas, Manohar L. Garg & Wayne S. Cutfield "Fish oil supplements in New Zealand are highly oxidized and do not meet label content of n-3 PUFA" Scientific Reports 5, Article number 7928. doi:10.1038/srep07928