The vegan omega-3 dilemma

Algal omega-3: twice as much DHA as EPA

For most people, vegetarian and vegan diets have a health halo.  The benefits are numerous, from reduced risk for chronic diseases to weight loss to better digestive function.  But there are plenty of potentially adverse nutritional consequences to consider.  Intake of several nutrients could be compromised without careful planning:

  • iron
  • protein
  • calcium
  • zinc
  • B12
  • vitamin D
  • omega-3 fats

That last one, omega 3 fatty acids, might not be on the nutritional radar screen for most people, but it’s one of the more difficult nutrients for vegetarians, and especially vegans, to consume.

But wait!  Aren’t many plant foods high in omega 3 fats?  Flax seed, chia seed, walnuts, canola oil and some other foods are known to be good sources of this extremely important fatty acid.  Why would omega-3 intake be a problem?  Here’s why.  The omega-3 from plant foods is entirely the 18-carbon alpha linolenic acid (ALA), a form of omega-3 not especially useful for all those omega-3 benefits we hear about.  In order to be effective, ALA must be metabolically elongated to 20-carbon eicosapentaenoic acid or 22-carbon docosahexaenoic acid.  These are readily available from animal-sourced foods like salmon or mackerel or tuna, but are absent in plant foods.  Humans have some ability to convert ALA to 20- or 22 carbon omega 3s, but not much.  It’s estimated that no more than 15% of the ALA consumed is ever converted.  Not a large amount, by any means.  And only if the vegan or vegetarian consumes plenty of those few omega 3 rich plant foods on a daily basis.

algal omega-3 that’s almost all DHA

Most EPA-DHA omega-3 supplements would not be suitable for vegetarians or vegans, since the omega-3 is sourced from fish.  What to do?  Recently algae has been used as a source of DHA, since certain types of algae contain this unique fatty acid.  While DHA is important for nerve, brain and eye function, EPA is equally important for other metabolic systems.  Supplements sourced from fish typically contain roughly equal concentrations of EPA and DHA, as found in nature (or EPA may be slightly higher).  Some vegan omega-3 supplements now contain algal-sourced EPA, although in lower concentrations than the DHA.  But at least these supplements have both of these important fatty acids.

What about foods fortified with algal omega 3?  Typically only very small amounts of added omega-3 will work in these foods, as the oils can go rancid or change the flavor of the food.  In many cases, the label may say “contains omega-3!”, but in fact only DHA has been added to the food, and only in a trivial amount, so again this isn’t a great reason to purchase one product over another.  If you’re considering a vegan omega-3 supplement, look for a product that includes both DHA and EPA, even if the DHA concentration is higher than EPA.  You are at least covering your bases with that choice. And even if you’re taking a supplement, don’t neglect high omega 3 foods like walnuts or canola oil.  These have a place in any meatless diet.

It might all sound complicated, but think about it this way: vegetarians and vegans now have access to good information about the importance of omega 3 fats and food sources, and can benefit from new technology that produces supplements from algae.  In fact, it may be that in the future, most omega-3 supplements will be derived from algae by default, as fish stocks dwindle, or fishing and processing becomes prohibitively expensive.

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