Translations:Omega-3 fatty acid/44/en

Rancidity

A 2022 study found that a number of products on the market used oxidised oils, with the rancidity often masked by flavourings. Another study in 2015 found that an average of 20% of products had excess oxidation. Whether rancid fish oil is harmful remains unclear. Some studies show that highly oxidised fish oil can have a negative impact on cholesterol levels. Animal testing showed that high doses have toxic effects. Furthermore, rancid oil is likely to be less effective than fresh fish oil.