Fish Oil. It’s Rancid. You Knew That.

Revealed: Many Common Omega-3 Fish Oil Supplements Are ‘Rancid’, The Guardian, 17 January 2022

Independent tests find that a number of products on the market use oxidised oils, with the rancidity often masked by flavourings.

You read it first here. Years ago. Fish oil (in fact, many oils you buy in a pill) are rancid. And rancid oils are not good. They are pro-inflammatory, and inflammation is at the root of many chronic illnesses. At the bottom of this post I’ll tell you what to do instead of taking fish oil.

More than one in 10 fish oil supplements tested from among 60 large retail brands are rancid, while nearly half are just under the recommended maximum limit [an arbitrary, unscientific, established-by-industry number], according to independent tests.
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Some fish oils recorded levels 11 times higher than recommended limits.

Rancidity arises when a product becomes oxidised. In fish oil, a rancid example can involve a strong fishy taste and rotten smell.

“It was fairly frequent,” said Dan Mark, Labdoor’s research director.

The rancidity is often masked by flavourings, which are added to most fish oils to reduce the fishy taste and smell.
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Fish oils are extremely popular, particularly in the US, where they are consumed by more than a third of adults who use dietary supplements. They are touted as an alternative to eating fish for getting omega-3 nutrients, and as beneficial for heart disease, improving brain function and strengthening metabolism*.
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Albert said smell was not a reliable indicator of oxidation. “Some fish oils will smell more than others, but if they don’t smell bad, that doesn’t tell you it’s not oxidised,” he said.

The article named a few brands that contained oxidized oils, including Carlson Labs, Puritan’s Pride, Oceanblue, and Nature’s Answer.

What To Do Instead
Eat plant foods. They contain shorter-chain omega-3 (ALA or alpha-linolenic acid) which the body converts to longer-chain omega-3 (EPA and DHA). It’s the EPA and DHA in fish oil that people are after.

If the body only converted 15% of the 2 grams of shorter-chain omega 3 you might eat in a day to longer-chain omega-3, that’s 300 mg of EPA+DHA. That’s more EPA+DHA than you can get in many fish oil or algal-based pills. One tablespoon of flax seed contains about 1.8 grams omega-3. Walnuts are another good source of omega-3 at 2.5 grams in 14 halves.

* “Strengthening metabolism”. What does that even mean? It’s like “natural” and “wholesome”. There’s no definition. What “metabolism” is being “strengthened”? Which tissues and organs and processes? And what does “strengthen” mean? It’s like “cleanse”. It’s just a feel-good term.