It’s been a long time since I published the Definitive Guide to Fish Oils .
Oh sure, here and there I’ve cited some research supporting the beneficial effects of fish fat, but it almost goes without saying that omega-3s are important. Everyone knows it. Even the most curmudgeonly, conventional wisdom-spouting, statin script-writing, lifestyle modification-ignoring doc will tell you to take fish oil . And research in the last few years has not only continually confirmed the health advantages but illuminated new applications—and new physiological explanations—for their essential function in the body.
But what are those benefits, exactly? Why should we be eating fatty fish or, barring access to high quality edible marine life, taking fish oil supplements ?
A major reason is that fish oil can help us reclaim our ancestral omega-3:omega-6 ratio and thus restore the inflammatory backdrop of the human body.
Polyunsaturated fats convert to eicosanoids in the body. Both omega-6 and omega-3-derived eicosanoids are important signaling molecules, but each has different effects, both figuring prominently in the body’s response to inflammation. Omega-6 eicosanoids are generally pro-inflammatory, while omega-3 eicosanoids are anti-inflammatory. Omega-3-derived eicosanoids (the type we get from taking fish oil or eating fatty fish) actually reduce inflammation; in an unbalanced diet heavy in vegetable oils, the omega-6 eicosanoids far outnumber the omega-3s and contribute to a lot more inflammation.
The best available evidence points to ancient humans having an omega-3:omega-6 ratio of around 1 to 1 . A typical ratio these days is 1 to 16!
As most diseases and health conditions have an inflammatory component, such lopsided ratios can predispose us to any number of health problems. Conversely, correcting those ratios with smart supplementation of fish oil  has the potential to correct or prevent those health problems.
Let’s look at some of them and what the most recent research tells us.
How Omega-3s Benefit Health
Arthritis is an inflammatory disease, whether we’re talking autoimmune arthritis or wear-and-tear arthritis.
The potential mechanisms are there . In vitro studies using isolated joint tissue show that both DHA and EPA increase joint lubrication. Studies in people show that fish oil reduces inflammatory markers and may even stop the progression of inflammation into inflammatory arthritis .
In a recent study  out of Thailand, knee arthritis patients who took fish oil improved their walking speed. “Everyone felt good and happy with the fish oil.” In psoriatic arthritis, fish oil reduced inflammatory markers and lowered patients’ reliance  on pain meds.
Fish oil also helps reduce the symptoms of autoimmune rheumatoid arthritis (RA). In one paper , fish oil supplements had additive effects on top of RA drugs. 3-6 grams appears to be an effective dose  range. If that sounds high, it is—but you need that much to quell the exaggerated inflammatory responses of RA.
Depression is another one of those conditions that we don’t often think of as an inflammatory disease, but it is. The evidence is considerable. Vets with the most severe depression also have the highest levels of inflammatory markers . Among Type 2 diabetes, depression and inflammation go hand in hand, with the latter appearing to play a causative role  in the former.
There’s considerable evidence that the causation goes both ways: depression can increase inflammation, and inflammation can increase depression. Thus, treating one may treat the other . Since omega-3s are potent and broad-reaching anti-inflammatories, could fish oil treat depression?
Fish oil has proven effective with EPA having a greater effect than DHA . It’s even effective  in patients with and without an official diagnosis of major depressive disorder. It’s effective in type 2 diabetics with depression .
The stress response is an inflammatory one. A healthy omega-3:omega-6 ratio—the foundation of our inflammatory response system—should produce a healthy stress response. Does it?
In response to mental stress, fish oil promotes  a healthy, less reactive neurovascular response. It lowers resting heart rate , a good indicator of general stress resilience. When taken post-trauma, it even reduces psychophysiological symptoms (like pounding heart) in car accident survivors . And in alcoholics, fish oil reduces  both perceived (subjective) stress and basal cortisol (objective).
General Inflammatory and Immune Responses
Name a disease and “elevated inflammation” or “exaggerated immune response” is probably part of the pathology. What effect does fish oil have on some of these inflammatory pathologies?
- Reduced inflammatory markers  (HS-CRP) in Type 2 diabetes patients.
- Improved inflammatory markers in colorectal cancer , including HS-CRP .
- Reduced airway inflammation  in asthma patients.
- Pre-op fish oil improved post-op inflammatory and immune markers in cancer surgery patients .
- Reduced inflammatory marker IL-10  in chronic Chagas cardiomyopathy, a serious heart condition.
- Reduced inflammatory gene expression  in humans.
I could go on and on. And these are just studies done in the last year or two.
Fish Oil and Cardiovascular Disease
Not everything is so cut and dry. When it comes to certain conditions, like cardiovascular disease, the fish oil literature is confusing. Sometimes it helps, sometimes it doesn’t. What are we to make of it ?
One thing that is unequivocal is that a high omega-3 index—the proportion of omega-3 fatty acids in the red blood cell membrane—is protective against cardiovascular disease (see the chart ; as omega-6 content goes up, so does cardiovascular mortality). So the question isn’t if long chain fatty acids from fish oil are helpful. It’s: Are those fatty acids reaching your red blood cell membranes and being incorporated?
How To Improve Bioavailability
Several factors affect whether fish oil will increase omega-3 index and thus have the effects we’re looking for:
Omega-6 fats and omega-3 fats compete for space in the red blood cell membranes. If omega-6 intake is too high, fewer omega-3s will make it into the membranes, thereby inhibiting or even abolishing the positive effects of fish oil.
If omega-3 index is low, we’ll see effects. If it’s high enough, further fish oil has no additive effect. We see this in studies such as this one , where only older adults with a low omega-3 index experienced cognitive benefits from omega-3 supplementation. In another study  of older adults and cognition that didn’t control for omega-3 index, they found no benefit.
Or in this study , where fish oil had benefits in congestive heart failure patients because they had low baseline levels of omega-3.
Or this study , where autistic patients—who tend to have lower omega-3 statuses than the general population—improved some behavioral measures after taking fish oil.
To take advantage of the full effects of fish oil, however, one must also limit the amount of omega-6 fats they eat. In one study, taking fish oil with saturated fat increased incorporation of omega-3s into red blood cell membranes , while taking it with omega-6 prevented omega-3 incorporation. The best way to do it is to eliminate seed oils—the most concentrated source of omega-6 fatty acids in the modern diet. If you don’t limit seed oils and other dense sources of omega-6s, you’ll have to consume extremely high doses of fish oil to make a dent in your inflammatory status.
Making It Easier To Get Your Omega-3s…
Thanks for reading today, folks. I take this information very personally in my life and business. To that end, we released a new formula of Primal Omega-3s  that enhances bioavailability and adheres to stricter environmental sustainability standards—all in a smaller capsule. The idea was to optimize benefits and maximize ease. And right now I’m also offering a deal to make this level of quality more affordable….
Thanks again, everybody. Have a great end to the week.