Call for fish oil paper’s immediate retraction
Call for fish oil paper’s immediate retraction, and apology
Natural Health Products NZ says that a NZ Medical Journal paper on fish oil products is so fundamentally flawed that it should be retracted immediately, and a public apology issued to the natural health products industry.
Natural Health Products NZ is the national industry organisation representing New Zealand’s natural products, functional foods, complementary medicines, cosmeceuticals and nutraceuticals industries.
Its concerns are in relation to the paper published today: “Are over-the-counter fish oil supplements safe, effective and accurate with labelling? Analysis of 10 New Zealand fish oil supplements”, authored by Julia J Rucklidge, Shelby Hantz and Ian C Shaw.
Natural Health Products NZ Chairperson Lorraine Moser says: “The paper’s researchers have made fundamental calculation errors in the way they have interpreted the omega-3 test results. The errors have resulted in completely the wrong conclusion being drawn about the label claims made by the fish oil products tested.”
Due to the calculation errors, the paper mistakenly concluded that 40% of the products tested for omega-3 fatty acids were accurate and true to label, while five others contained between 48 and 89 per cent of the amount listed. The paper also stated that just one of the products contained the amount listed on the label.
In reality, 90% of the products met their label claims.
How did this happen?
Samples of all 10 products were analysed by a reputable independent laboratory, which always conveys its results as X amount per gram.
The tested fish oil products had different capsule sizes. Some capsules were 1 gram, some were 1.5 grams and others were 2 grams. When the laboratory analysed these capsules, in keeping with its normal testing practises, it stated all results in terms of the amount of omega-3 per gram.
When calculating the quantity of active ingredient in each capsule, the researchers failed to take account of the fact that the test results were in 1 gram units, so should therefore have been extrapolated for larger capsule sizes.
When assessing the label claims for products with 1.5 gram capsules, the researchers did not multiply the test results by 1.5 to give an accurate result.
Correctly extrapolating the test results for each capsule size has identified that all but one of the tested products were well within acceptable tolerances related to their label claims.
Ms Moser says the paper has presented label claim inaccuracy fiction as fact, needlessly damaging the industry’s reputation and needlessly giving consumers cause for concern.
“New Zealand’s natural health products industry has incredibly high standards in terms of product quality and ethical behaviour.
“Ensuring natural health products are safe, effective and contain what is stated on the label lies at the very heart of what we and our members do so it is incredibly frustrating to see shonky research like this not only being published, but also publicised,” she says.
Further questions about the research methodology
Ms Moser went on to say that Natural Health Products NZ was surprised to see that today’s NZ Medical Journal paper is based on a Masters thesis dated January 2016. That thesis has the same calculation flaws as the Medical Journal paper. The testing work for that thesis was carried out in 2015 and therefore those results are five years old.
“We would be interested to know when the testing was done for products discussed in the NZ Medical Journal paper. Was the paper referring to tests done five years ago, or was more recent testing done?
“If the test results are five years old then – regardless of the researchers’ calculation errors – we question the relevance and ethics of using such old data to draw conclusions about products sold now.”
Ms Moser went on to say there are other flaws in the research methodology, which further undermined the robustness of the research paper and the original thesis upon which it was based, but the most significant issues were the flawed calculations and questions around when the products were actually tested.
What should happen next
Natural Health Products NZ believes the NZ Medical Journal should immediately retract the paper, remove it from their website, and issue a media statement to this effect.
Natural Health Products NZ will also be contacting the researchers and requesting a public apology for damage to the industry’s local and international reputation – particularly companies that sell fish oil products. Retailers also deserve an apology because it is possible that publicity surrounding the erroneous research will affect their sales.
Media who have covered the initial research have a moral obligation to balance that coverage with the issues raised here, so that consumers are made aware of the research paper’s inaccuracies.
Natural Health Products NZ will also be drawing this matter to the University of Canterbury’s attention and request that it review processes associated with the original thesis upon which this paper is based, and the paper itself.