Fish oil capsules and supplements fail on Omega-3 claims and freshness, University research study
Most fish oil supplements sold in Australia and New Zealand are lower in omega-3 fatty acids than their labels claim, according to new research the University of Newcastle and the University of Auckland.
Looking at 32 brands of fish oil capsules marketed in Australia and New Zealand, the researchers found that only three contained the same concentrations of omega-3 fatty acids as listed on the label. The study was published in the journal Nature on 21 January 2015.
Health benefits of fish oil and omega-3s
The researchers said fish oils were among the most popular dietary supplements in the world, with more than a third of the 17.7 per cent of US adults who use dietary supplements taking fish oil. Fish oils contain significant quantities of omega-3 long-chain polyunsaturated fats.
Omega-3 fatty acids have been associated with several health benefits, including lowering inflammation, improving cognition and lower cardiovascular disease risk. Australian Food News reported in September 2014 that a study had found fish oil may help with heart health and seizure frequency in adults with epilepsy. In August 2014, Australian Food News reported that another study had found omega-3 fatty acids may help lessen the severity of osteoarthritis, and in August 2013, Australian Food News reported that a lack of omega-3 fatty acids had been associated with an increase in anxiety levels and hyperactivity in teenagers.
In contrast, Australian Food News reported in July 2013 that omega-3 fatty acids had been associated with an increased risk of prostate cancer.
Fish oils ‘highly oxidised’
The researchers from the University of Newcastle and the University of Auckland found that the vast majority of supplements tested exceeded recommended levels of oxidisation markers. Only 8 per cent of the tested fish oil supplements met international recommendations.
The researchers said that surprisingly, best-before date, cost, country of origin and exclusivity were “all poor markers of supplement quality”.
Health and nutrition experts have responded to the study, with some calling for regulators to get involved.
“This is very useful, interesting and important information,” said Professor Peter Clifton, Head of the Nutritional Interventions Laboratory at Baker IDI Heart and Diabetes Institute and Professor of Nutrition at the University of South Australia. “Clearly the bulk fish oil producers have been deceiving the public and the encapsulators about the EPA and DHA content of their oil and the ACCC and the Therapeutic Goods Administration need to get involved,” he said.
Professor Clifton said that for those consumers trying to get an anti-inflammatory or triglyceride lowering effect from fish oil, the study could explain why the product “may not be working for them”, even if they were taking the recommended number of capsules.
“Similarly, the high oxidation products may be interfering with how well the pills work but we really don’t know the long term implications of high oxidation products,” Professor Clifton said.
“As the paper points out it is possible very oxidised fish oil may promote the formation of fatty deposits in the arteries and thus the opposite of what the consumer is expecting, and may even account for some of the recent negative clinical trials if the EPA and DHA were significantly oxidised,” Professor Clifton said.
Professor Murray Skeaff, Professor in Human Nutrition at the University of Otago called for the researchers to publish the brand names of the fish oils supplements that were analysed “so that consumers may be able to identify the supplements of highest quality”.
“If the results are accurate, then fish oil supplements in New Zealand can be added to a long list of dietary supplements for which there are serious discrepancies between what the manufacturer claims the consumer is getting and what is actually in the supplement,” Professor Skeaff said. “Of additional concern is that the vast majority of the fish oil supplements contain amounts of oxidised fats that exceed recommended levels, in other words the oils are on the road to becoming rancid if not already so,” he said.