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One in 10 fish oil supplements marketed in the US are chemically decomposed


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Fish oil supplements are hard to trust, warned Ben Albert, fellow at the University of Auckland.

More than one in 10 fish oil supplements tested among 60 large retail brands are rancid.

Rancidity arises when a product becomes oxidised, and can involve a strong fishy taste and rotten smell.

Labdoor measured branded fish oils in the US against international standards of rancidity.

The GOED set a recommended limit at 26, an arbitrary and unitless measure of oxidation.

Half of all products bordered at an average of 24.4.

Carlson’s Norwegian cod liver oil - 281.8; Puritan Pride’s soft-gel fish oil - 37.1; Oceanblue - 73.9; Nature’s Answer - 34.4.

Global studies published in Nutrition Reviews showed that 20% of fish oil products have excess oxidation.

Studies published in Scientific Reports by Albert noted that 92% and 20% of products exceeded recommended limits in 2015 and 2017, respectively.

Nature’s Answer responded that results over 25 indicate improper handling and storage before being tested.

Labdoor's report indicate only the freshness of supplements; toxicity effects remain unclear

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Paediatrician and Paediatric Endocrinologist, as well as Senior research fellow at Liggins Institute


Tests and ranks supplements, helping consumers to buy the best product


Journal providin information about nutrition and dietetics.


Scientific Journal providing information from all areas of the natural sciences.