Differentiation of ALA (plant sources) from DHA + EPA (marine sources) as Dietary Omega-3 Fatty Acids for Human Health

It is truly annoying and mind boggling to keep hearing the vegans claim you get enough Omega 3 from non-meat sources. They refer to flax, walnuts, canola oil, etc. as sufficient sources. In their foolish quest to rid the world of meat eating they fail to realize that this Omega 3 is ALA (a-linolenic acid) not the superstars DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). All of the research showing the myriad benefits of Omega 3 oils is based on DHA/EPA not ALA!

Omega-3 fatty acids (n-3 polyunsaturated fatty acids)…Certain plant sources (and derived vegetable oils) such as flaxseed, canola oil, walnuts, etc. contain significant amounts of the plant-based omega-3 fatty acid known as a-linolenic acid (ALA, 18:3n-3). …Flaxseed and other plant-derived oils are totally lacking in DHA/EPA combined whereas DHA/EPA are found in fish/fish oils which contain very minor amounts of ALA. ….

…A recent study seeing flaxseed oil rich in ALA has confirmed a moderate rise in circulating plasma lipid levels of EPA plus DPA (but not DHA); the authors suggest that this rise, although moderate, in EPA plus DPA might possibly mediate any beneficial effects towards cardiovascular health derived by the consumption of flaxseed oil. It should be noted herein that the published literature using deuterated ALA suggests conversion efficiencies of dietary ALA to EPA plus DHA (combined) ranging from 5-15% overall….

While the claim is made that ALA supplementation does seem to improve cardiovascular outcomes I find the claim rather dubious. A 5% -15% conversion rate? And what about DHA which is essential for the development of the brain?

Furthermore:

Several factors inhibit conversion of ALA to it's long-cchain Metabolites (EPA and DHA)

• A diet high in LA (common in US) can inhibit conversion by as much as 40%
• A high maternal intake of linoleic acid (Omega 5 from corn, safflower oil, etc.) inhibits conversion to EPA and DHA reduces n-3 availability to the developing fetus
• increasing the ratio of n-3 to n-6 fatty acids in the diet with ALA may not enhance neuronal DHA levels in infants
• Saturated and trans fatty acids inhibit ALA desaturation and elongation
• Ethanol inhibits conversion of ALA to EPA and DHA
• a deficiency of any of the vitamins and mineral co-factors (vitamin B3, B6, C, Zinc and Magnesium) required by elongase and Delta-6 desaturase may inhibit conversion of EPA and DHA
• Loss of Delta-6 desaturates activity that occurs during norman aging
• Certain health conditions such as diabetes and drugs, inhibits Delta - 6 saturase activity and prevents conversion of EPA and DHA
• Certain populations, such as North American natives, Inuit, Orientals, Norwegians, and Welsh-Irish may not effectively convert ALA to EPA in the body

I think I have heard enough about how wonderful ALA is as an Omega 3 source. Have you?

Eat your meats!