RE: Another EFA question

November 19, 2001

> Thanks for all your responses about Chelation. I finally

understand

> it.

>

> My next question is What is the difference between Complete Omega

> from Nordic Naturals and ProEFA?

>

> Thanks in advance.

>

November 19, 2001

basically nothing, one is a professional label the other is a

commercial.

See message #5612 from

February 5, 2003

>>>>>Are linoleic and alpha linolenic acid really essential? That is,

assuming

hypothetically that one could consume EPA, DHA, GLA, and AA in isolation,

would it still be necessary to consume LA and ALA?

----->brandon, i don't know for sure, but i'd think so. the parent efas -

ALA and LA play more rolls than just serving as eicosanoid precursors. they

play structural rolls in membranes, and LA in particular is concentrated in

the skin. I would rather have a two double bond fatty acid concentration in

my skin than a 4 double bond fatty acid. i would guess AA (or DHA

especially) would be more prone to oxidation induced by UV light than LA. as

well, an 18 carbon two double bond FA may make any given cell membrane just

the right amount of rigidity in the way that a 20 carbon 4 double bond FA

couldn't do (might make it too fluid). i'm just guessing that since the body

has this pool of different carbon length and double bond PUFAs to draw from

to make each cell membrane just the right amount of rigidity, while still

maintaining fluidity (for materials to pass through), that having the larger

pool is somehow important. otherwise i can't imagine why ALA and LA would be

ubiquitous in both the animal and plant kingdom (er, queendom :-)

aside from that it would be virtually impossible to avoid LA and ALA unless

you ate a totally synthetic diet since they are present in all plants and

animals, AFAIK.

Suze Fisher

Lapdog Design, Inc.

Web Design & Development

http://members.bellatlantic.net/~vze3shjg/

mailto:s.fisher22@...

February 6, 2003

At 01:55 PM 2/5/03 -0800, you wrote:

>Are linoleic and alpha linolenic acid really essential? That is, assuming

>hypothetically that one could consume EPA, DHA, GLA, and AA in isolation,

>would it still be necessary to consume LA and ALA?

>

>--

> Berg

>bberg@...

From The Nutrition Almanac pg. 56

The need for lineolic acid increases in proportion to the amount of solids

eaten. If the intake of saturated fat is high,a deficiency of lineolic acid

can

occur even though oils are included in the diet,and increased consumption of

foods as butter, cream and saturated fat increases the need for vitamin F.

Eating a great deal of carbohydrates also increases the need for unsaturated

fatty acids. When there is sufficient lineolic acid in the diet, the other two

essential fatty acids can be synthesized from it.

In the beginning of this Vitamin F (unsaturated fatty acids) it says " The body

cannot manufacture the essential unsaturated fatty acids, lineolic,linolenic

and arachidonic,and they must be obtained from food.

If this is so where was the lineolic acid say with the Masai? In their

livestock's meat or milk? They didn't eat any of the food sources listed here.

Wheat germ, seeds, natural golden vegetable oils such as safflower, soy, corn

and cod liver oil.

Wanita

February 6, 2003

-

>Are linoleic and alpha linolenic acid really essential? That is, assuming

>hypothetically that one could consume EPA, DHA, GLA, and AA in isolation,

>would it still be necessary to consume LA and ALA?

That's a good question. I think the answer is yes, but not necessarily for

the reasons usually cited. LA and ALA are commonly deemed essential

because the body can't synthesize them, and EPA, DHA et al unessential

because the body can synthesize them, but the body can't synthesize nearly

enough of the latter, so I think the nomenclature is actually rather

misleading in this case.

Another point to consider is that there are small quantities of LA and ALA

in meat.

When faced with shortages of the fats it really needs, the body will turn

to whatever fats it can find or make, so the mere fact that LA and ALA are,

for example, used in cell membranes doesn't necessarily mean they're

essential. After all, the body will incorporate trans fats from

hydrogenated vegetable oils into cell membranes if that's what it has to

work with -- and we certainly don't consider trans fats essential. But

since LA and ALA do occur at least in small quantities in foods we

unquestionably evolved to eat, it certainly wouldn't be surprising if they

were essential, at least in some quantity. How much, though... well,

that's a harder question.

-

February 6, 2003

>>>>That's a good question. I think the answer is yes, but not necessarily

for

the reasons usually cited. LA and ALA are commonly deemed essential

because the body can't synthesize them, and EPA, DHA et al unessential

because the body can synthesize them, but the body can't synthesize nearly

enough of the latter, so I think the nomenclature is actually rather

misleading in this case.

---->i agree, and there are numerous factors that can interfere with the

synthesis of longer chain PUFAs from the parent PUFAs, so it's not a good

idea, imo, to rely on LA and ALA for your total EFA requirements.

>>>>>>When faced with shortages of the fats it really needs, the body will

turn

to whatever fats it can find or make, so the mere fact that LA and ALA are,

for example, used in cell membranes doesn't necessarily mean they're

essential.

------>well, the point i was making is that they are unique in their

configuration and ability to keep cell membranes just fluid enough to allow

materials to be transported in and out, but without being so fluid that cell

contents spill out. i can't think of any other fatty acids that could

replace them due to their unique configuration of multiple double bonds -

which other fatty acids don't have. i'm ignoring brandon's hypothetical of

eating the long chain PUFAs and not the shorter chain ones, because it's not

doable in any practical sense since LA and ALA are present in both animal

and plant foods. imo, they are likely there for a reason. we can eat tons of

fish and organ meats to get the longer chain PUFAs. so why would we need the

shorter chain ones at all? why has nature 'put them' in virtually all the

natural foods that humans eat?

there are so many factors that affect the body's need to make some cell

membranes more fluid than others, and i don't think monounsaturates could

take the place of PUFAs in doing so under all possible conditions. take the

case of a study of PUFA distribution in reindeer - the researchers found

that the apendages and skin, as well as fat depots closest to the skin's

surface had the highest PUFA concentration which allowed the

triacylglycerols to be metabolically usable. this was at -20C, well below

the temp of an average refrigerator. if those external triglycerides had the

higher ratio of saturated fat that surrounds the deer's internal organs,

they'd solidfy at that cold temperature. the PUFAs are necessary in such

cold climates for appendages to NOT solidify and to allow outer fat stores

to be metabolically usable. I'm guessing these external depots might also

solidfy, at least partially, or no longer be as metabolically usable as

necessary to maintain normal bodily functions, if those PUFAs were replaced

by MUFAs.

I think it's also likely that *humans* in such cold climates also require a

relatively high proportion of PUFAs to maintain normal cellular function in

depots close to the skin's surface in such a cold climate. it makes sense

when you consider that arctic animals and plants naturally have high PUFA

content. It's there for a reason, or two.

Suze Fisher

Lapdog Design, Inc.

Web Design & Development

http://members.bellatlantic.net/~vze3shjg/

mailto:s.fisher22@...

February 6, 2003

Suze-

>there are numerous factors that can interfere with the

>synthesis of longer chain PUFAs from the parent PUFAs, so it's not a good

>idea, imo, to rely on LA and ALA for your total EFA requirements.

Exactly. I don't have the figures handy, but even under the best of

circumstances, our ability to elongate LA and ALA is somewhere around 1%,

so we're really getting very little EPA and DHA and whatnot from elongation

no matter what, and many things can interfere with that already-minimal

ability.

>why has nature 'put them' in virtually all the

>natural foods that humans eat?

Well, that's just it -- I expect that since they're there naturally, we

need them. But not huge amounts of them (LA and ALA) probably.

>I think it's also likely that *humans* in such cold climates also require a

>relatively high proportion of PUFAs to maintain normal cellular function in

>depots close to the skin's surface in such a cold climate.

Yes and no. The problem is that modern man has indoor heating, so he's

either going to be adapted to his home and hearth -- and his office, and

the heated interior of his car, and so on -- or to the cold outside, but

not to both. Since excess PUFA has so many ill effects, I'd be inclined to

eat more for the inside than for the outside. Ray Peat has some

interesting comments on the Eskimos too, though I don't think he has the

whole story about lipid chemistry, and Steffanson also noted that the

Eskimos actually keep extremely warm in their igloos and furs. So unlike

animals which are actually indigenous to such frigid regions (and which

therefore will face less oxidative stress on their large depots of PUFAs)

we don't necessarily need or make nearly so much of a metabolic and

physiological adaptation.

-

February 7, 2003

>I think it's also likely that *humans* in such cold climates also require a

>relatively high proportion of PUFAs to maintain normal cellular function in

>depots close to the skin's surface in such a cold climate.

>>>>>Yes and no. The problem is that modern man has indoor heating, so he's