Myth: A stale fish oil supplement works just as well as a fresh fish oil supplement at lowering cholesterol.
Truth: This is false.
According to a recent study published in the British Journal of Medicine, fresh fish oil supplements have been proven to be more effective at reducing low-density lipoproteins (LDL) and intermediate-density lipoproteins (IDL) in comparison to sunflower oil and stale fish oil supplements. The freshness of the fish oil supplement plays an effect on how much cholesterol can be lowered because the supplements experience degrees of oxidation over time.
Fish oils contain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that oxidize due to peroxide formations, reducing the efficacy of fish oils. This research study divided experimental groups into fresh fish oils, oxidized fish oils, and sunflower oils to determine the difference in cholesterol levels. The study found that fresh fish oils were better able to reduce the number of total lipids, phospholipids and total cholesterol esters in IDL and small LDL in comparison to sunflower oil and oxidized fish oil. This study yields important implications in taking high-quality fish supplements and those that are not expired on the market. Oxidation of fresh fish oil supplements occurs as soon as the supplement makes contact with the air and will remain fresh depending on the manufacturer’s guidelines.
For more information about this study, click here.
Reference
- Rundblad A, Holven KB, Ottestad I, Myhrstad MC, Ulven SM. High-quality fish oil has a more favourable effect than oxidised fish oil on intermediate-density lipoprotein and LDL subclasses: a randomised controlled trial. Br J Nutr. 2017;117(9):1291-1298. doi:10.1017/S0007114517001167
 and intermediate density lipoproteins (IDL) in comparison to sunflower oil and stale fish oil supplements.){kind=link}