8 kinds of omega 3?
I am currently taking Marks Omega 3 supplement, but I just can across an article that says there are 8 members of the omega 3 family. These are the EPA and DHA listed on the bottle of PB fish oil capsules I have, as well as: DPA SDA, ETA(3), ETA, HPA, and ALA. Now, at the end of the article, the author links to their product, but still, I am now wondering of my supplement is truly beneficial. Help
here is the site I got my info from
ALA (alpha-linolenic acid) is the form of omega-3's found in flax, hemp seed, leafy greens, seaweed, etc - basically it is the 'raw' form found in plant life. The human body will convert ALA to DHA/EPA at a very inefficient rate - I've heard anything from 1% to 15% - in any case, it isn't worth wasting the time and digestion on flax/hemp based omega-3 supplements. Leafy greens have dietary value, but not for this reason.
Other animals are more efficient than we are at converting to DHA/EPA; this is why we eat things like fish, grass fed ruminants, and naturally fed eggs.
If you check out wikipedia, it looks like DHA can be synthesized from EPA, which is first broken into DPA. I think they're all basically sub-forms of each other via the oxidation process. DHA is the most important fatty acid, as a majority of the brain and retina consists of it.
Okay, that makes sense, and is consistent with what I have read elsewhere. However, if anyone knows for certain about SDA ETA and HPA, please do post. Meanwhile, I'll do some more digging, and post what I find for others.
ALA is an 18 carbon long fat with 3 double bonds. DHA at the end is a 22 carbon long fat with 6 double bonds. To convert ALA to DHA it must be elongated (add two carbons) twice and desaturated (add double bond) 3 times.
That's 6 omega 3s already. I hope this helps you understand some part of why the conversion of ALA to DHA (the good stuff) is so difficult and almost non-existant. The ones to focus on are EPA, DHA and incidental DPA. The rest have limited use. Standard fish oil covers these bases well.
as Stevenhamley said, most of those omega 3's are intermediate steps in the conversion process from ALA into DHA and are less common in diet than EPA/DHA/ALA
I have read some interesting stuff about SDA tho, apparently some claim that it's the first step from ALA to SDA that is the major limiting factor in conversions leading to DHA in humans, and starting with SDA is far more efficient.
Development of plants rich in SDA is underway as a potential alternative to fish oils for dietary supplements. IIRC Monsanto is working on GMO Soybean traits that produce SDA, and field trials of Echium are underway.
Well, here I go digging through various bio-chemistry articles, just to find a very good explanation from Stevenhamley.
I must conclude from all of this that the supplement company on whose website I read about the lesser-known variations of Omega 3, is merely leveraging the supposed ignorance of prospective customers against them. As I am understanding all of this, the supplementation of the initial and intermediate forms Omega 3 in a human being, is redundant and lacking in benefit. What a great Sisson Blog Post topic this would be....