Omega 3: EPA versus DHA

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Thomas
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Omega 3: EPA versus DHA

Post by Thomas »

With regard to long-chain omega 3 fatty acids, which is more beneficial in terms of strengthening/expanding neural tissue, 22:5 or 22:6?

I can buy DHA omega 3 eggs, but our only source of EPA seems to be fish.
How much of a difference does it make?
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RRM
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Re: EPA versus DHA

Post by RRM »

Thomas wrote:With regard to long-chain omega 3 fatty acids, which is more beneficial in terms of strengthening/expanding neural tissue, 22:5 or 22:6?
Both DPA (22:5) and DHA (22:6) are essential in neural (re)generation, but the influence of DHA seems to be bigger. (Mozzi et al, Neurochem Res 28(2): 195-214.)
I can buy DHA omega 3 eggs, but our only source of EPA seems to be fish.
How much of a difference does it make?
Both EPA (20:5) and DHA (22:6) can partially be made by our own body (from LNA); but men are less capable than women though Bakewell L et al. So, you do need dietary EPA and DHA indeed.
As far as I know, in egg yolks, the amount of EPA is unknown, not "0". So, maybe there is no issue regarding egg yolks at all. To be on the safe side, you better eat some raw fish occasionally as well.
avalon
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Omega 3s

Post by avalon »

Here's an interesting bit:
Eating oily fish and seeds in pregnancy can boost children's future brain power and social skills, research suggests.

A study of 9,000 mothers and children in Avon suggested those who consumed less of the essential fatty acid Omega-3 had children with lower IQs.
From:

http://news.bbc.co.uk/2/hi/health/4631006.stm

Sure wish my Mom had known this :shock:
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Post by RRM »

Copied from another thread:
Mr. PC wrote:I was told by my doctor that your body can convert omega 3 into 6 and 9
No, thats not possible.
Both the omega-3 ALA (alpha-linolenic acid) and the omega-6 LA (linoleic acid) are essential nutrients; the body cannot convert one into the other.
Thats is why they are called essential fatty acids (EFAs).
If the body could convert ALA into LA, LA would not be an essential fatty acid.
The reason why omega-3s and omega-6s are competitive, is because they share the same enzymes required for further conversions.
The body can, for example, convert the omega-6 LA (18 carbon) into a "longer chain" omega-6 fatty acid: arachidonic acid (20 carbon).
The body can also convert some of the "short chain" (18 carbon) omega-3 ALA into "long chain" (20 and 22 carbon) omega-3 fatty acids (like EPA and DHA).

Eventually, all fatty acids (including omega-3s and omega-6s) are eliminated / used for energy through beta-oxidation
(the sequential removal of 2-carbon units by oxidation at the β-carbon position of the fatty acyl-CoA molecule).
Thus the long carbon chains get increasingly shorter.
Changing the number of double bonds in those long chains of fatty acids (which defines them as omega-3, -6 or -9) is a whole different process.
Mr. PC wrote:it's basically impossible to have too much omega 3.
Not really; everything in the body is about balance.
In 2000 the FDA issued a warning that excessive intakes (dietary + more than 2 grams from supplements) of EPA and DHA may result in
hemorrhagic stroke and reduced glycemic control among diabetics.

What is important is the omega 3 ratio.
Both EPA (20:5) and DHA (22:6) can partially be made by our own body (from LNA; about 5% conversion rate).
DPA (22:5) is an intermediary between EPA and DHA, and DPA limits DHA synthesis, and vice versa. Both DPA and DHA are essential in neural (re)generation.
So, i believe that its important to balance the omega 3 fats by consuming them from natural sources (fish, eggs, meat).

http://www.waiworld.com/waidiet/nut-omega3.html
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Re: Omega 3: EPA versus DHA

Post by RRM »

From http://www.raw-food-health.net/Vegetarian-DHA.html
The only two essential fatty acids the body cannot do without are the the omega-3, alpha linolenic acid (ALA) and the omega-6, linoleic acid (LA). The body is fully equipped to manufacture as much DHA as it needs using ALA.
So where do Omega-3 and 6 come from? The only life forms that can create these two fats are plants. All animals (including humans and fish) are unable to make the fats themselves and must eat plant foods to get enough, although excess fatty acids can be stored in the body, and a predator can obtain them by eating another animal.

When animals have enough omega 3 and 6 fatty acids, they convert them into the derivatives need for the proper function of the body, including EPA and DHA.
Humans have no difficulty in converting ALA into DHA in the liver, thus supply our needs (1).
Although vegetarians and vegans test lower in DHA, nutritional researchers have concluded that it's not an issue.

Researcher Thomas Sanders, author of the "DHA status of vegetarians," which appeared in the August-September 2009 issue of the journal of Prostaglandins Leukotrienes and Essential Fatty Acids, wrote that "…the relatively lower intake of linoleic acid and the presence of preformed DHA (fish) in the diet of omnivores explain the relatively higher proportion of DHA in blood and tissue lipids compared with vegetarians. In the absence of convincing evidence for the deleterious effects resulting from the lack of DHA from the diet of vegetarians, it must be concluded that needs for omega-3 fatty acids can be met by dietary ALA (alpha linolenic acid).” (2).

Because ALA is derived from plant sources, there's nothing to worry about as long as you're eating enough fruits and vegetables.
One study looking at women on Vegan Diets showed they have more long-chain Omega-3s, compared with fish eaters, meat eaters, and ovo-lacto vegetarains. Vegan men did not have quite the as high of levels as the women (3).
Yet despite zero intake of long-chain DHA, vegan participants converted robust amounts of shorter-chain fatty acids into these long-chain fatty acids (3).

1) Langdon JH. Has an aquatic diet been necessary for hominin brain evolution and functional development? Br J Nutr. 2006 Jul;96(1):7-17.
2) Sanders TA. DHA status of vegetarians. Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):137-41.
3) Welch AA, Shakya-Shrestha S, Lentjes MAH, Wareham NJ, Khaw KT. Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans and the precursor-product ratio of a-linolenic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort. Am J Clin Nutr. 2010;92:1040-1051.
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Re: Omega 3: EPA versus DHA

Post by RRM »

The only two essential fatty acids the body cannot do without are the the omega-3, alpha linolenic acid (ALA) and the omega-6, linoleic acid (LA). The body is fully equipped to manufacture as much DHA as it needs using ALA.
That requires a study about the optimal DHA levels.
Vegetarians have lower DHA levels.
Whether that lower level or a higher level is optimal, remains to be investigated.
"...infants born to mothers with higher plasma phospholipid DHA suggest greater central nervous system maturity" Cheruku SR et al
Humans have no difficulty in converting ALA into DHA in the liver, thus supply our needs (1).
...
(1) Langdon JH. Has an aquatic diet been necessary for hominin brain evolution and functional development? Br J Nutr. 2006 Jul;96(1):7-17.
The study quoted (Langdon JH) did not measure anything like that.
Its just a review of hypotheses.
It actually says that "both the maternal and infant bodies have mechanisms to store and buffer the supply of DHA, so that functional deficits are generally resolved without compensatory diets."
In other words:
Consuming no DHA for a while (resulting in "functional deficits") is overcome by eating (for example) fish later....
The study does not claim that humans "have no difficulty in converting ALA into DHA in the liver, thus supply our needs".
It merely claims that:
the hypothesis that DHA has been a limiting resource in human brain evolution must be considered to be unsupported.

It has been shown that the capacity to convert ALA into DHA is limited and not the same for all humans.
Comparing the results of various studies, women, for example, may possess a greater capacity for ALNA conversion than men. Burdge GC et al
Although vegetarians and vegans test lower in DHA, nutritional researchers have concluded that it's not an issue.
....
In the absence of convincing evidence for the deleterious effects resulting from the lack of DHA from the diet of vegetarians, it must be concluded that needs for omega-3 fatty acids can be met by dietary ALA (alpha linolenic acid).” (Sanders TA).
Sanders indeed confirms that: "The proportions of DHA in plasma, blood cells, breast milk, and tissues are substantially lower in vegans and vegetarians compared with omnivores."
and writes that "There is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians."
but actually concludes that:
"The pathophysiological significance of this difference remains to be determined.".
He did not write that "its not an issue".
He wrote that "the capacity to synthesize long-chain polyunsaturated fatty acids (in general) is not limited."
This does not mean that the capacity to convert ALA in DHA is not limited.
He actually writes that extra ALA does not result in extra DHA in blood lipids.
Whereas even the smallest increase in dietary DHA does result in extra DHA in blood lipids.
Apparently, the body gratefully accepts all the extra DHA it can get.
One study looking at women on Vegan Diets showed they have more long-chain Omega-3s, compared with fish eaters, meat eaters, and ovo-lacto vegetarains.
Yes, the ALA levels are higher.
Why?
Because the DHA levels are lower.
And potentially, ALA may get converted into DHA.
As the DHA levels remain low, it may be wise to stock up on ALA.
Yet despite zero intake of long-chain DHA, vegan participants converted robust amounts of shorter-chain fatty acids into these long-chain fatty acids (Welch AA et al).
Zero intake of DHA?
Below the header "Ratio of ALA intake to the sum of EPA and DHA intakes" (below table 7), the article says:
"Comparison of the PLLC n−3 PUFAs:DALA ratio between dietary-habit groups showed that it was 209% higher in vegan men and 184% higher in vegan women than in fish-eaters"
The source of the dietary DHA: commercial sauces etc.
But yes, naturally, the lower the omega 3 intake, the greater the percentage of ALA converted to DHA.
However, the eventual blood DHA level is substantially lower in vegans.
Also, it is said in this article that:
"The limitations of this study are that we were only able to estimate a precursor-product ratio
as a statistical estimate of potential conversion, actual conversion was not measured
"
overkees
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Re: Omega 3: EPA versus DHA

Post by overkees »

So what can we conclude? That eating fish is always good when it comes to omega 3. But if you don't there aren't a lot of problems either. As long as you consume enough yolks and fruit?

So eating some herring or mackerel once every two weeks to be sure.
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Re: Omega 3: EPA versus DHA

Post by panacea »

I don't think EPA from fish is very important. In fact I would argue that it's extremely unlikely that all of the worlds human population evolved on a diet of fish - which are hard to catch without tools. Therefore the likely conclusion is that our EFA requirements are very small and adequately covered by foods such as egg yolks or foods which would have tiny amounts of EPA in them in the wild like termites or birds eggs or whatever. Here's some interesting info!

Abstract
Current reviews and textbooks call the omega-6 linoleic acid and the omega-3 alpha-linolenic acid "essential fatty acids" (EFA) and cite the EFA requirement as one to four percent of calories. Research suggests, however, that the omega-6 arachidonic acid (AA) and the omega-3 docosahexaenoic acid (DHA) are the only fatty acids that are truly essential.

Eicosapentaenoic acid (EPA) occurs in fish products but is probably not a normal constituent of the mammalian body and in excess it interferes with essential AA metabolism. The EFA requirement cited in the scientific literature is inflated by several factors: the use of diets composed mostly of sucrose, glucose, or corn syrup; the use of diets deficient in vitamin B6; the use of purified fatty acids instead of whole foods; the use of questionable biochemical markers rather than verifiable symptoms as an index for EFA deficiency; and the generalization from studies using young, growing animals to adults.

The true requirement for EFA during growth and development is less than 0.5 percent of calories when supplied by most animal fats and less than 0.12 percent of calories when supplied by liver. On diets low in heated vegetable oils and sugar and rich in essential minerals, biotin, and vitamin B6, the requirement is likely to be much lower than this.

Adults recovering from injury, suffering from degenerative diseases involving oxidative stress, or seeking to build muscle mass mass may have a similar requirement. For women who are seeking to conceive, pregnant, or lactating, the EFA requirement may be as high as one percent of calories. In other healthy adults, however, the requirement is infinitesimal if it exists at all.

The best sources of EFAs are liver, butter, and egg yolks, especially from animals raised on pasture. During pregnancy, lactation, and childhood, small amounts of cod liver oil may be useful to provide extra DHA, but otherwise this supplement should be used only when needed to obtain fat-soluble vitamins.

Vegetarians or others who eat a diet low in animal fat should consider symptoms such as scaly skin, hair loss or infertility to be signs of EFA deficiency and add B6 or animal fats to their diets. An excess of linoleate from vegetable oil will interfere with the production of DHA while an excess of EPA from fish oil will interfere with the production and utilization of AA. EFA are polyunsaturated fatty acids (PUFA) that contribute to oxidative stress. Vitamin E and other antioxidant nutrients cannot fully protect against oxidative stress induced by dietary PUFA. Therefore, the consumption of EFA should be kept as close to the minimum requirement as is practical while still maintaining an appetizing and nutritious diet.
______

The PUFA Report Part 1: A Critical R[/b]eview of the Requirement for Polyunsaturated Fatty Acids
overkees
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Re: Omega 3: EPA versus DHA

Post by overkees »

Ah nice! Then I can eat fish just for the taste and don't need to feel bad if I don't consume it for a few days.

I like organic grass fed beef with yolks way better than the fish. I started with the fish in the beginning because wai advocates it. But when I tried raw beef a while ago, eating fish sometimes disgusts me. I was eating it against my will, for the omega 3's. Also when considering the pollutants in sea fish i prefer beef. I think eating land animals is closer to our nature and I think it is highly unlikely that we were bloating ourselves with insects. More like people who ate left overs of large animals that weren't eaten by predators. That's why we've gotten those handy hands, opponating fingers :D.
panacea
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Re: Omega 3: EPA versus DHA

Post by panacea »

why would insects 'bloat' us? I don't mean just any insects, but termites for example, is there anything suggesting they would be any more hard on our digestive system than an egg yolk, or beef?
it's pretty safe to assume we didn't evolve our type of hands so we can pick at carcasses, as is evidenced by apes having our style of hands and not using them mainly for that purpose.

I think we would certainly get sick and die in the wild if we picked at 'left overs' of large animals unless we hung out right after the kill (can you say dangerous). And I don't think they would leave any 'scraps' that we would be interested in.
overkees
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Re: Omega 3: EPA versus DHA

Post by overkees »

I'm sorry I didn't meant bloating. I meant that I couldn't believe we ate so many insects. So many to get a lot of these omega 3's. Because monkeys eat lots of m, but they don't have this bigger increase in brain capacity.

There must somewhere be a difference. And if we compare the food that chimps eat with humans, we see we eat a lot more animal food than they. So somewhere in our nature we began eating more animal foods. So I was thinking that it can't be the insects, but rather left overs. If a predator is finished he is full. It's like going to the supermarket when you just had a thanksgiving dinner. He won't hurt a fly. If you time this well, you can eat fresh food like brains, that aren't eaten by the predator. And we can easily pick it out of the skull. I think this kind of left overs caused our boost in intelligence.

Why wouldn't other monkeys do so? Because they live more in the forests. We were the monkey group that was forced to move out of our gardens in to the big empty fields. Or just went by itself? Here we were forced to eat these kind of things, because there weren't so much fruits as in the forest.

If this theory fails to explain it, then i suggest another theory: The stoned ape theory, by Terrence McKenna. Could be a possibility too. http://www.youtube.com/watch?v=hOtLJwK7kdk
panacea
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Re: Omega 3: EPA versus DHA

Post by panacea »

There would have been much more birds eggs, reptile eggs, insects and worms than there would have been safe animal brains lying around. In order for a specie to evolve based on diet you need a consistent food source spanning many thousands of years. The likelihood that dead animal brains was a significant factor for many thousands of years is very unlikely without the use of tools - and we couldn't have used sophisticated tools without some brain growth in the first place.. so logic suggests that, since eggs, insects, and worms are very rich in brain development related nutrients, that human mothers would have had richer amounts of these nutrients in their breast milk than chimpanzees, making human babies slowly more able to support a larger and more energy-consuming brain. If you look at studies done on comparing baby human/chimp brain growth, you will see that we start out very similar, and mainly the human baby's prefrontal cortex grows more rapidly and ends up much larger.
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Re: Omega 3: EPA versus DHA

Post by RRM »

panacea wrote:... the likely conclusion is that our EFA requirements are very small and adequately covered by foods such as egg yolks or foods which would have tiny amounts of EPA in them
Indeed, as the level of DHA in the blood substantially increases when a vegan person consumes a tiny bit of DHA.
Comparable to the intake of minerals; the less is consumed, the higher the percentage ending up in the blood.
And, as with minerals, there is a certain (low) minimum intake that you need to fulfill. (hence the lower blood levels in vegans)
overkees
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Re: Omega 3: EPA versus DHA

Post by overkees »

Seems like the wai site needs to update their fish section and meat section. Those should be only for taste and protein regeneration.

Going yolks all the wai. :D
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Re: Omega 3: EPA versus DHA

Post by Oscar »

Let's not forget that a) Nature tends to work in scarcity and survivability/sustainability, but we're looking at optimal, and b) we only recommend fish above meat because of the prevalent harmful bio-industry practices, not because of it actually being better.
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