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The flax seed oil scam

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Marketing droids try to make you believe that their stuff is as good as fish oils. They're wrong, and they know it.

First, there is the ratio of omega 3 fatty acids to omega 6 fatty acids: most cold-pressed oils, most grain-fed meat animals, and most farm-fed fish have an abundance of omega-6 fats and very little omega-3 fats.

We'd need these two in a ratio of 1 part omega 3 to 1 part omega 6. We get them, in a typical diet, in a ratio of 1:6 or so. Hence the need for omega-3 fatty acids.

Next, there's the two types of omega-3 fatty acids:

Some plant oils (linseed (= flax seed) oil, among others) contain alpha-linolenic acid (ALA), a short-chain omega-3 fatty acid.

The fats in cold-water fish (cod, salmon, herring and the like) contain long-chain omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

The scam is in flax seed oil folks trying to maintain that we can convert ALA into EPA and DHA in anything like relevant amounts.

We can't. We convert at most 10 %, but usually less than half that.

Here's a study from 1998, but this has been fairly common knowledge with nutritionists since at least 1985:

Gerster H: Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?
Int J Vitam Nutr Res 1998;68(3):159-73

A diet including 2-3 portions of fatty fish per week, which corresponds to the intake of 1.25 g EPA (20:5n-3) + DHA (22:6n-3) per day, has been officially recommended on the basis of epidemiological findings showing a beneficial role of these n-3 long-chain PUFA in the prevention of cardiovascular and inflammatory diseases. The parent fatty acid ALA (18:3n-3), found in vegetable oils such as flaxseed or rapeseed oil, is used by the human organism partly as a source of energy, partly as a precursor of the metabolites, but the degree of conversion appears to be unreliable and restricted. More specifically, most studies in humans have shown that whereas a certain, though restricted, conversion of high doses of ALA to EPA occurs, conversion to DHA is severely restricted. The use of ALA labelled with radioisotopes suggested that with a background diet high in saturated fat conversion to long-chain metabolites is approximately 6% for EPA and 3.8% for DHA. With a diet rich in n-6 PUFA, conversion is reduced by 40 to 50%. It is thus reasonable to observe an n-6/n-3 PUFA ratio not exceeding 4-6. Restricted conversion to DHA may be critical since evidence has been increasing that this long-chain metabolite has an autonomous function, e.g. in the brain, retina and spermatozoa where it is the most prominent fatty acid. In neonates deficiency is associated with visual impairment, abnormalities in the electroretinogram and delayed cognitive development. In adults the potential role of DHA in neurological function still needs to be investigated in depth. Regarding cardiovascular risk factors DHA has been shown to reduce triglyceride concentrations. These findings indicate that future attention will have to focus on the adequate provision of DHA which can reliably be achieved only with the supply of the preformed long-chain metabolite.

Try his other study as well:

Gerster H.: The use of n-3 PUFAs (fish oil) in enteral nutrition.
Int J Vitam Nutr Res. 1995;65(1):3-20.

Severely ill patients in need of enteral nutrition support must obtain all essential nutrients in at least the amounts recommended for daily intake (RDA) by healthy populations. Until recently essential fatty acids have been entirely omitted from enteral solutions or included only in the form of n-6 PUFAs which are structurally important for cell membranes and play a significant role as precursors (esp. arachidonic acid, AA) of eicosanoids (prostaglandins, thromboxanes, leukotrienes). However, in the absence of n-3 PUFAs, these eicosanoids may produce exaggerated effects in acute stress responses causing immunosuppression, platelet aggregation and excessive or chronic inflammation. n-3 PUFAs act as precursors of complementary eicosanoids which counteract the exaggerated responses of AA-derived eicosanoids. Therefore, n-3 PUFAs should be part of any optimally balanced diet and must be included also in enteral solutions. Since the transformation of the n-3 parent fatty acid, alpha-linolenic acid, to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is slow and unreliable, it is necessary to provide them as preformed nutrients as they occur in fish oil. The British Nutrition Foundation recommends a daily intake of EPA and DHA in amounts corresponding to the intake of 3 to 4 g standardized fish oil. The requirements can also be covered by the weekly consumption of 2 to 3 portions of fatty fish. Preliminary clinical trials have shown certain beneficial effects of fish oil intakes in diseases associated with inflammatory reactions such as rheumatoid arthritis or inflammatory bowel disease, in conditions with impaired immune competence such as burns, post-operative situations and cyclosporine treatment after renal transplants, and in conditions with enhanced platelet aggregation such as after coronary angioplasty. While these findings must be verified in strictly controlled trials, the intake of fish oil n-3 PUFAs in a balanced ratio to n-6 PUFAs can be recommended for all patients including those in need of enteral nutrition support.


Ditch the linseed oil in favor of fish oils.

I dislike flax seed oil for another reason as well: it oxidizes (goes rancid) pretty much the minute it's pressed, and unless it's been refrigerated ALL the way from press to consumer, it's ALWAYS rancid.

And it's never a very good idea to add rancid fats to an already inflammatory body.

In fact, flax seed oil goes rancid so fast that a rag drenched in it heats up, if left to itself. Cottonseed oil does the same. Many a school has gone up in flames because the woodworking evening class teacher hasn't paid attention to what his students have used in their furniture polishings ... and hasn't checked the bins for oily rags, before turning off the lights of an evening.

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