Posted by Larry Hoover on April 5, 2003, at 17:37:12
In reply to Re: Another fish oil question! » Larry Hoover, posted by Viridis on April 5, 2003, at 16:03:30
> Hi Larry,
>
> Thanks very much, and sorry for making my question so open-ended. I guess what I'd really like to know in sorting through all of this are the relative utilities of the various unsaturated fats and the functional differences between omega 3s vs. omega 6s.In general terms, most people get far too much omega-6, relative to omega-3. Estimates of the ratio between them run from 15:1 to 50:1, based on assessments of typical Western diets. "Ideal" ratios would be somewhere around 2:1. Your diet sounds like it's closer to the latter than the former.
Omega-6s are pro-inflammatory. That's probably the biggest issue.
> Not that that's a simple question either, but here's my current approach:
>
> I have a fairly low intake of saturated fats, but don't really worry about them (e.g., I'll use butter over margarine any day). I avoid artificially hydrogenated oils as much as possible and am pretty alert to where they're used. In cooking, we use mostly monounsaturates (primarily olive oil, some peanut), and occasionally canola. I take fairly high doses of fish oil, with an intake of around 1.2 g EPA and 1 g DHA/day.
>
> Now, I think all of this is pretty sensible.Looks good to me.
>Where I really get confused is with the multitude of other oils that are touted for their health benefits. I use various oils (hemp, walnut, grapeseed etc.) as flavorings, in salad dressings, and so on, and I assume that adding this variety has some benefits.
The whole idea of flavour helps to describe the benefits; it's the components that give flavour that confer extra health benefits, e.g. the flavonoids and terpenes and so on. You've already covered the fatty acid profiles nicely. You don't need large quantities of anything else, with one possible exception (below). So, go ahead and use these oils as you have been. Most people touting all the health benefits of e.g. hemp oil also sell it, right? Go figure.
>But what about additional supplementation with flaxseed, borage, evening primrose, etc. -- is there anything special about these that "rounds out" the range of lipids that your body needs, or do I have it pretty much covered anyway?
What makes borage, evening primrose and black currant seed oils special is their high GLA (gamma-linoleic acid) content. Although this is an omega-6 fatty acid, in the presence of sufficient omega-3 intake (you've got that well covered), this particular fatty acid will be diverted into the production of anti-inflammatory prostaglandins. So, you might get a little bit of a health benefit from adding one of the three I mentioned. Flax oil has high ALA (alpha-linoleic acid), the omega-3 version. You won't get appreciable benefit from flax oil because you're male. There's a gender difference in the ability to elongate and desature.
> And, finally, just what is the significance of the position of the C=C bonds -- why is it their precise location apparently so important?One of the ways that polyunsaturates are turned into signalling compounds is by the formation of a ring structure. The enzyme we know as COX (cyclo-oxygenase) does that. The ring takes up six carbons, so for a 20-carbon fatty acid like EPA, you'll have these two tails comprising 14 carbons in total sticking out. Something about just what sticks out has meaning to your body. After the ring is formed, other modifications occur which further change the "information" carried by the molecule. You can get cytokines, interleukins, prostaglandins,....all kinds of stuff, depending on the modifications. I don't pretent to know anything about the coding per se, but the three-dimensional configuration, surface electron density and so on can switch biological systems on and off.
Just to show you how little we really know, it is only recently that the natural signalling chemical for what we call the cannabinoid receptor was identified. It's called anandamide, and it's an amide derivative of the 20:4 polyunsaturate arichidonic acid. The arichidonic acid is itself derived from neuronal membrane fatty acid stores.
> I guess I've still left you with a huge amount of material that potentially could be covered, but I'd appreciate your insights into the above.
>
> Thanks again,
>
> ViridisIf I've missed the mark, try some new questions.
Lar
poster:Larry Hoover
thread:216119
URL: http://www.dr-bob.org/babble/20030402/msgs/216502.html