Many fish oil supplements sold commercially do not contain the amount of EPA and DHA claimed on their labels, show signs of degraded fats beyond safe limits, and may contain harmful contaminants like heavy metals.
Evidence from Studies
Supporting (5)
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Fish oil supplements in New Zealand are highly oxidised and do not meet label content of n-3 PUFA
Most fish oil pills sold in New Zealand don’t have as much healthy omega-3s as they say, and many are already spoiled or rancid by the time you buy them.
This study found that many fish oil pills in China don’t have as much EPA and DHA as they say, smell bad because they’re going rancid, and sometimes contain harmful metals — exactly what the claim says.
This study found that many fish oil pills don't have the amount of healthy fats they say they do on the label. That means you might not be getting what you paid for, but it didn't check for bad stuff like mercury or spoiled oil.
This study checked fish oil pills sold in Bahrain and found that most didn't have as much healthy omega-3s as they claimed, and many were already spoiled from exposure to air — just like the claim says.
Omega-3 fatty acid fish oil dietary supplements contain saturated fats and oxidized lipids that may interfere with their intended biological benefits.
This study found that many fish oil pills don't have as much healthy omega-3s as they say, have gone bad (oxidized), and are filled with other fats that shouldn't be there — meaning they might not work and could even be harmful.
Contradicting (0)
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Gold Standard Evidence Needed
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