3/3 TOP-Selling US Fish Oils Exceed Maximal Peroxide and Total Oxidation Levels - Levels Roughly 4000% Higher Than in Medical Grade N3 Supplements, Harvard Study Shows

The US' favorite fish oil supplements: Dirt cheap and still not worth the money. Better buy fish - fresh fish.
"I told you so!" That's how someone else in my position would probably start today's blogpost. In view of the fact that "smartassing" is not exactly an effective means of education, I will yet refuse from reminding you that I've been reporting about unwanted side effects of the gold-ish pills that claim to have "fish oil" in them on various occasions.

And guess what!? The publication of a recent study by scientists from the Cardiovascular Division, Brigham and Women's Hospital at the venerable Harvard Medical School, gives me yet another reason to rant against the evermore popular fish oil supplements.
You can learn more about omega-3 & co at the SuppVersity

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In their study, the scientists analyzed 3 commonly available fish oil dietary supplements and found that (a) their level of omega-3 fatty acids varied significantly, that (b) they contained tons of other fats that you would ask to be paid for to consume if you knew about them and, that (c) the caps were so full of oxidized fats that they exceeded international standards and may (d) may harm, rather than help with your health.

No, we're not talking about cheap Chinese internet purchases, bro!

The Harvard scientists bought the "three top-selling fish oil DS [dietary supplements] in the United States and to examine the extent of oxidative damage in the DS as compared with chemically characterized standards with respect to purity and ability to prevent human sdLDL oxidation in vitro" (Mason. 2016). The commonly heard excuse that this is "just a problem with the cheap Chinese stuff" is thus as useless as it is ridiculous in view of the data from the study at hand.
Figure 1: The TOP3 US fish oil products are rancid... well, mostly (right hand side) and they have almost no ability to prevent human LDL particles from oxidation, as the results of the MDA test on the left indicates (Mason. 2016).
Compared to the medical grade control, the US top-sellers look as if they had been tainted with motor oil from a fishing cutter. Speaking of which: I would not guarantee that the 34%, 21% and 24% of "other oils" in this so-called dietary supplements do not include at least tiny amounts of mineral oils.
Your fish oil contains 4000% more oxidized fats than prescription fish oil! That's a huge problem, because many of the studies you're so fond of, because they seem to prove how healthy fish oil is, have been done with medicinal grade fish oils. Accordingly, the results of these studies have ZERO predictive power with respect to what your "machine oil" fish oil will do to your health. Speaking of "your" - it is not impossible that the oxidative damage occured during storage, which reminds me to remind you NEVER to use fish oil in a bottle that's constantly exposed to pro-oxidative oxygen, whence you've opened the bottle. Note: If stored in the fridge (4°C) the shelf life of the fish oil in fresh fish is, as Boran et al. show in their 2006 paper in Food Chemistry ~ 90 days.
In fact, the scientists measured not just primary oxidation products, as the highly elevated peroxide levels, an indicator of high levels of primary oxidation and hydroperoxides, confirm, but also secondary products of the decomposition of the primary oxidation products during continued exposure to oxidative conditions, as they ar detected in the p-anisidine test.
Figure 2: Indeed, there was also some "fish oil" in the caps - emphasis on "also" and "some" (Mason. 2016)!
The total oxidation levels in Figure 1 were then derived from the peroxide and anisidine values indicate without fail that "[a]ll three DS exceeded the recommended maxima for peroxide and total oxidation values (5 meq/kg and 26, respectively) when normalized to 1 g OM3FA (based on the number of capsules needed to achieve 1 g of OM3FA)" (Mason. 2016). The latter is particularly shocking in view of the fact that the prescription product of pure OM3FA did not contain significant levels of these oxidation products under identical test conditions. Any studies on the health effects of fish oil - mostly conducted with medical grade capsules - is thus meaningless for the average consumer who shies away from the exorbitant costs of LOVAZA and co. - a bad mistake, as it turns out, now, that the Harvard scientists' study shows that EPA and DHA containing oxidized trash fats from the dietary fish oil supplements have a >77% reduced ability to protect your LDL oxidation from (>90% protection for pure products, a meager 21 ± 4% for the "fish oil" you have probably been buying for years).

Speaking of "for years": Is it possible that you've done more harm than good in the past years of consuming copious amounts of fish oil to your health? Yes, it is, but in view of the fact that even the "motor oil" version of fish oil in the average US dietary fish oil supplement (the brand names are obviously undisclosed = not mentioned in the paper) was still anti- and not pro-oxidative, it's more likely that you have only wasted time and money.
Only three brands, but unfortunately in line with previous research: The scientists make no secret of the fact that a major limitation of their study "is that, although [they] evaluated the top-selling DS in the United States, [they] only assessed three products given the scope of this initial investigation" (Mason. 2016). Bad luck for fish oil fans: e results of this study are consistent with previously published analyses of DS with respect to content and oxidative damage" (ibid.) - studies that didn't just find oxidized fatty acids, but also heavymetals and cholesterol in the pills.
So what do we make of these results? Well, I guess it depends on how indoctrinated you've already been about fish oil being an essential supplement (the word "supplement" already implies that it cannot be essential). If you actually believe in the magic of fish oil (imho bogus for healthy individuals), you should go and buy pharma grade fish oil spending your whole monthly supplement budged on fish. If, on the other hand, you've any sanity left, you simply do what I've been recommending for years: eat your fatty fish once or twice per week (doesn't have to be wild-caught | Farmed Fish is Less Poluted and Has More Omega-3) | Comment!
  • Boran, Gökhan, Hikmet Karaçam, and Muhammet Boran. "Changes in the quality of fish oils due to storage temperature and time." Food chemistry 98.4 (2006): 693-698.
  • Mason, PR and Sherrat SCR. "Omega-3 fatty acid fish oil dietary supplements contain saturated fats and oxidized lipids that may interfere with their intended biological benefits." Biochemical and Biophysical Research Communications - Available online 21 December 2016 | In Press, Corrected Proof
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