Dr. Deborah’s MD blog
I like bacon, but….
”…One of the problems with the standard American diet is that we have switched dramatically in recent decades from a traditional balance of omega-6 and omega-3 fats. Paleolithic diets and modern hunter-gatherers boast a 6/3 ratio of as low as 1/1, as high as 3-5/1, the entire range excellent and in fact deemed optimal by international agreement. By comparison, the conventional American diet, with a bit of fast food thrown in, ranges fro 15 to 30/1, WAY too much omega 6’s. …”
”…Now, bringing all this home: I recently did some nutritional testing and found out that despite eating excellent sources of omega-3 fats, my omega-3 index was not up to par. Looking through the lists of foods and their 6/3 ratios, the two problems I identified are perhaps too much pork and nut proteins, and not enough omega 3’s. …” .…More
Why the Omega-3/Omega-6 Ratio May Not Matter After All By Mark Sisson
Here’s how it’s supposed to work:
Linoleic acid converts to arachidonic acid (AA), a precursor for inflammatory cytokines.
Alpha linolenic acid (ALA; plant omega-3) converts to the anti-inflammatory precursors EPA and DHA, the omega-3 fatty acids we usually associate with fish oil.
Both of these conversions occur along the same rate-limited enzymatic pathway, which means they “compete” for a spot.
If we eat too much linoleic acid, the story goes, our tissue levels of AA will spike and predispose us to excessive inflammation and all the disease fallout that entails. Actually, increasing dietary linoleic acid doesn’t really increase the tissue level of arachidonic acid. Instead, since both linoleic acid and ALA use the same conversion pathway, an excess of linoleic acid does inhibit the conversion of ALA into EPA and DHA, leading to potential deficiencies in the latter nutrients and promoting an inflammatory environment – if you don’t eat preformed EPA and DHA in the form of seafood, pastured animal products, and/or supplements to make up for it.
That’s right: people for whom a fish dinner means battered and fried tilapia sticks are at risk of an inflammatory omega-3/omega-6 ratio, but people following a Primal way of eating are probably safe. Just eating some salmon, sardines, mussels, and pastured eggs can undo a lot of the damage caused when linoleic acid hogs the conversion pathway. Linoleic acid, however, is not directly increasing tissue omega-6 levels.
It appears as if the problem with low ratios of omega-3 to omega-6 is the lack of omega-3, not so much the omega-6. In studies that replace saturated fats with omega-6 fats, the only ones that show benefit are those that also include omega-3s with the omega-6s, while those that replace SFA with just omega-6 increase the risk of death. As long as you’re eating enough fish and other seafood, pastured animals and their fat (and eggs), and/or high quality fish oil supplements, whole food sources of omega-6 shouldn’t increase inflammation. The ratio is a helpful way to monitor your omega-3 and omega-6 intake, but it’s not a physiological law.
That’s not our only issue with linoleic acid, though. Where do we get our omega-6 fats?
No, not you reading this. Not the guy who asks that his eggs be cooked in butter or olive oil at the diner. Not the lady who shudders at the sight of one of those three gallon Costco jugs of corn oil. Where do most people living in industrialized nations get their omega-6s? You know, “normal” people.
Americans get almost 70% of their PUFA (mostly omega-6) from oils, shortening, and margarine and just 6% from beans, seeds, and nuts, 1% from eggs, and 13% from meat, poultry, and fish as of 2004 (PDF). So when we talk about omega-6 intake, we’re really talking about french fries (cooked in vegetable oil), packaged pastries (made with shortening), and processed, high-sugar, high-(vegetable)fat junk food intake.
If most of our omega-6 is coming from the linoleic acid found in cooking oils and processed baked goods, most of the omega-6 we’re eating is highly oxidized, rancid, and maybe even worse. …More
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