Shoot forward another hundred years or so, and those same omega-3 fatty acids staked out another claim to fame when it was discovered that there was an inverse association between omega-3 fatty acid ingestion (through fatty fish) and cardiovascular disease in certain Eskimos.

This led to omega-3 fatty acids from fish oil being inextricably linked to heart health. But, in a case of double-irony or, hell, I don't know, history kind of repeating itself, there are now whispers of fish oil being just another "snake oil," at least when it comes to preventing cardiovascular disease.

That's the result of different randomized controlled trials finding conflicting results when it comes to the effectiveness of fish oil in reducing the risk for cardiovascular disease. It seems they ignored two recent meta-studies (studies that compile the findings of a bunch of related studies) that found significant reductions in risk for myocardial infarctions in those who took supplemental omega-3 fatty acids.

Never mind all that, though. A new study has come out of South Dakota that ought to, once and for all, confer to fish oil (on Amazon) the status that it deserves. Not only did this study – another meta-study – find an inverse association between omega-3 fatty acids and cardiovascular disease, it found an inverse relationship between omega-3 intake and ALL causes of mortality.

William Harris and his colleagues collected 17 separate epidemiological studies that followed the dietary history and disease states of 42,466 men and women for 16 years.

Many of them died from various causes over the course of the 16-year period – 15,720 of them to be exact. However, Harris found that those with high or higher levels of DHA, EPA, and DPA (n-3 docosapentaenoic acid, another omega-3) were 15 to 18% less likely to die from cardiovascular disease, cancer, you name it, than those with relatively low levels of the omega-3 fatty acids.

Interestingly, those that had high levels of ALA, the plant-based omega-3, didn't appear to acquire any Methuselah-like traits.

So maybe you're asking, why should we believe this study when others have found conflicting results? Well, for a couple of reasons. For one, this was a meta-study, not just a singular study, and the compiled results of 17 studies carry more weight than the findings of one.

Secondly, and perhaps more importantly, many if not most fish oil studies have relied on self-reported fish intake. This was not the case with the Harris study. Instead, they actually measured blood levels of omega-3s.

Studies that rely on self-reported fish intake are prone to inaccuracies. You're relying on test subjects' memories of when they ate fish and how much fish they ate.

Secondly, the seafood industry is rife with corruption. Much of the time, when you order a particular fish for lunch or dinner, you get something else entirely. A study by the Oceana group a few years found that up to 74% of fish in sushi restaurants was misrepresented, while the fraud rate in restaurants was 34%.

Consider, too, the recent Subway sandwich scandal. According to reports, their famed tuna sub contained zero tuna DNA. I haven't read any reports identifying what type of fish it really contains, but my bet is on escolar, a type of snake (there's that word again) mackerel. Escolar is a cheaper, lower-omega-3 fatty acid fish that's often called the "Ex-Lax fish" for the anal leakage it causes.

My point is this: The high omega-3 fish you think you're ordering might be something else entirely.

Similarly, if you bought a package of allegedly fresh salmon in any month but June, July, and maybe part of August, it's not wild, Pacific salmon. Instead, it's probably farm-raised Coho, King, or Atlantic salmon because nearly all Pacific salmon are caught during the summer months, and they can't legally be farm raised.

This is critical because wild salmon eat their nature-intended diet and develop their pink or reddish color naturally, which indicates they're chock-full of the healthful omega-3 fatty acids we humans covet. This isn't the case with farm-raised salmon. They're fed a diet of fishmeal and grain, which makes them naturally lower in omega-3 fatty acids.

Clearly, self-reported fish intake studies are vulnerable to all kinds of errors. Measuring blood levels of omega-3 fatty acids, as the researchers in Harris' meta-study did, is a lot more accurate and a lot more convincing.

Harris and colleagues theorized that high(er) levels of omega-3 fatty acids could extend lifespan by the following mechanisms:

• High levels of omega-3 fatty acids lower blood pressure and triglycerides while making platelets less "sticky" (thus making strokes less likely).
• High levels of omega-3 fatty acids have anti-inflammatory effects.
• High levels of omega-3 fatty acids lower chronically elevated levels of mTOR, thus showing benefits against cancer and metabolic syndrome (in addition to depression).
• High levels of omega-3 fatty acids have also been linked with slowing the rate of telomere shortening, thus lengthening the "lifespan" of chromosomes and, ipso facto, you.

"In summary," wrote the researchers, "in a global pooled analysis of prospective studies, LC (long chain) n-3 PUFA (polyunsaturated fatty acids) levels were inversely associated with risk for death from all causes and from cardiovascular disease, cancer, and other causes."

In laymen's terms, fish oil (along with other sources of omega-3s) is most definitely not a snake oil.

Look for molecularly distilled, pharmaceutical-grade DHA/EPA re-esterified triglycerides with more DHA than EPA (since DHA is the real powerhouse). Obviously, I'd recommend the one we make: Biotest Flameout®.

1. Harris WS et al. Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies. Nat Commun. 2021 Apr 22;12(1):2329. PubMed.