Talk:Docosahexaenoic acid

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	Chemistry Portal Docosahexaenoic acid is within the scope of WikiProject Chemicals, a daughter project of WikiProject Chemistry, which aims to improve Wikipedia's coverage of chemicals. To participate, help improve this article or visit the project page for details on the project.
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Article Grading: The following comments were left by the quality and importance raters: (edit · history · watch · refresh) I judge DHA to be of 'High' importance due to the coverage it gets in the popular press; tho you might not cover it until a grad-level class. Good so far: Nice intro (tho it dives down into the details prematurely) Filled out chembox Many high-quality references, well formatted. At least a little bit of text on most of the important ideas. ToDo: Initial characterization and synthesis (who, when, where) Discuss how Burr and Burr first showed it was an EFA. Source of the resolvins and other docosanoids NPOV problems with 'Superiority of Algae Derived DHA in Infant Nutrition' More on dietary sources A whole lot more on its function in the brain subsection on role in the retina biosynthesis from EPA; when is this adequate? Absorption in the GI tract; transport, uptake by various tissues Use as a dietary supplement Rancidity Factor in DNA transcription Membrane fluidity Pictures UV, Mass Spec spectra? Diagram showing its release from cell membrane / action of COX Picture of natural sources - fish, seal The recent Martek patent fight over DHA as an additive The whole 'which is more important - DHA v EPA?' question needs to be addressed in detail somewhere and at least summarized here.

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B	This article has been rated as B-Class on the assessment scale.
High	This article is on a subject of high-importance within molecular and cellular biology.
Article Grading: The following comments were left by the quality and importance raters: (edit · history · refresh · how to use this template) I judge DHA to be of 'High' importance due to the coverage it gets in the popular press; tho you might not cover it until a grad-level class. Good so far: Nice intro (tho it dives down into the details prematurely) Filled out chembox Many high-quality references, well formatted. At least a little bit of text on most of the important ideas. ToDo: Initial characterization and synthesis (who, when, where) Discuss how Burr and Burr first showed it was an EFA. Source of the resolvins and other docosanoids NPOV problems with 'Superiority of Algae Derived DHA in Infant Nutrition' More on dietary sources A whole lot more on its function in the brain subsection on role in the retina biosynthesis from EPA; when is this adequate? Absorption in the GI tract; transport, uptake by various tissues Use as a dietary supplement Rancidity Factor in DNA transcription Membrane fluidity Pictures UV, Mass Spec spectra? Diagram showing its release from cell membrane / action of COX Picture of natural sources - fish, seal The recent Martek patent fight over DHA as an additive The whole 'which is more important - DHA v EPA?' question needs to be addressed in detail somewhere and at least summarized here.

Removed link to fish oil blog .com which is clearly a commercial site and violates Wilepedia guidelines.

Contents 1 Commercial Site? 2 Pageblanking 3 Preferred Dietary Sources of DHA for Humans 4 Is the formula correct? 5 Nevada Study 6 Nevada Study Changes 7 Vegan/vegetarian study 8 Autism??

[edit] Commercial Site?

It doesn't appear to be a commercial site to me. I would like to hear your reasons for saying this is a commercial site.

[edit] Pageblanking

Same site has removed Talk discussions of fishoilblog link from this page and the Talk pages for EPA, Fish oil and Cod liver oil

[edit] Preferred Dietary Sources of DHA for Humans

I moved this section and text to talk:

Fish oil has long been touted as a superior form of DHA compared to non-marine vegetable sources. A recent study showed that infants fed DHA derived from algae did better than children fed DHA from fish oil.

because

• Using 'tout' isn't in keeping with NPOV
• No citation for the claim that fish oil is perceived as superior to non-marine sources
• Algae is a marine source; fish oil is (largely?) derived from algae in the food chain
• No citation for a recent study
• No indication as to by what measure the infants 'did better'.

David.Throop 14:45, 9 April 2006 (UTC)

I have cleaned up the language and placed the reference back in the doc with a specific citation. --Rjms 16:54, 11 April 2006 (UTC)

Thanks for the improvement. But the cited study compares a mixture of algal/fungal mixture to a fish-oil/algal mixture. Also, from the citation, it's not possible to tell if the amounts of AA/EPA/DHA in the mixtures were identical. The full study is behind the Elsiver subscription wall. Has anybody seen the full study? The citation alone doesn't establish that algal DHA is superior to fish-oilP DHA. David.Throop 01:26, 30 October 2007 (UTC)

The study cited compares four groups: breast-fed infants, formula-fed infants, formula-fed infants with algal DHA and fungal AA, and formula-fed infants with fish-derived DHA and fungal AA. The conclusion in the abstract only states that formulas supplemented with DHA and AA result in "enhanced growth", and does not differentiate between the performance of the fish oil DHA and the algal DHA. mordel (talk) 22:39, 8 January 2008 (UTC)

I have added the POV flag on the algae source section. Just for the sake of transparency, the cited study was sponsored by Mead Johnson Nutritionals... Guess which blend of DHA they put in their infant formula... Shall I suggest to rename this section: "Current controversies on impact of purity of DHA on its benefits" or anything alike... Jerome Samson (talk) 09:36, 20 December 2007 (UTC)

[edit] Is the formula correct?

Is the formula correct? I think it perhaps should be C22 H32 O2 (not C22 H34 O2 as at present). The molecular mass of 328.488 and the diagram of the molecule agree, but are not consistent with the formula given; see also the sigmaaldrich or PDR health sites where the formula is given as C22 H32 O2. I think the CAS number is 6217-54-5. (added by a newcomer - apologies if the protocol of this posting is incorrect - and I'm too new to actually dare changing the page itself, although a number of Open University students with this molecule in an assignment may not thank me for not immediately making the correction!) Stephenet 22:35, 18 April 2007 (UTC)

[edit] Nevada Study

Although I agree with the original poster's POV, I've removed the commercial references from the mainspace text and have summarised the study to state what it does show - not what it *might* show. If one claims *proof* beyond the scope of the referenced study, then one is also obliged to evaluate all similar studies and address alternate explanations. István 14:55, 14 June 2007 (UTC)

[edit] Nevada Study Changes

I changed "plant-derived" to "algae-derived" to avoid confusing people who do not realize that the only known source of plant derived DHA is from algae, not flax or another land based source. --RJMS 02:10, 15 June 2007 (UTC)

[edit] Vegan/vegetarian study

The line "This, and features of the production and distribution of DHA in pregnant and lactating women, indicates that DHA per se is an essential nutrient." does not seem to belong in the section of DHA studies of Vegans and Vegetarians; the fact that vegans' DHA levels do not rise when given ALA supplements doesn't indicate the "essentialness" of DHA. The citation leads to an article about whether DHA is essential, with only a note about vegans:

"In contrast to the ease by which DHA status is influenced by dietary intake, it has become clear that humans are rather poor DHA synthesizers. This notion comes from studies showing the following:

... The inability of dietary ALA supplements to augment DHA status in vegans has been observed despite their low baseline DHA status (25). "

which, is actually another reference to the actual study: [1]

Maybe there should be separate sections discussing DHA/veganism and whether DHA is essential?

Also, the study seems to only have included vegans, and though vegetarians wouldn't be eating fish/meat either, it would probably be more accurate to leave it at just "vegans". Faunablues 22:07, 8 September 2007 (UTC)

There a tremendous fallacy gap here: There is no citation that shows excess levels of DHA in the bloodstream is of greater benefit than excess levels of ALA in the bloodstream. For example, I could increase the amount of engine oil in a car tenfold, but it would still function the same. But low levels of the oil is clearly problematic.

In other words, the body synthesizes what is needed from the ALA, so excess levels of DHA would not be present. Though pumping vast amounts of DHA into the bloodstream would show high levels of DHA in the bloodstream. What missing is the gap -- that extra amounts of DHA in the bloodstream a better condition then the equilibrium level provided by ALA.

---

The above discussion was not signed. Regarding this discussion post, I have not been able to find information whether the body synthesizes what is needed from ALA or not, do you have a citation for this? Perhaps the poster intended to write 'if the body synthesizes what is needed form the ALA, then excess levels of DHA..." Although there is also a section in this article which indicates the body can convert other compounds into DHA, the jury appears to be out whether this is 'what is needed' or not. Also, in the into to the DHA article, the content indicates that 'very little DHA is manufactured by the body', also seemingly without citation, then mentions 'mounting evidence' (at the end of the intro) for supplementation, referencing non-specific links at the end of the page, which I can't find. Is there sourced material for these areas of content? DHA is also mentioned in the 'prostate cancer' article in Wikipedia, linking to this page, with inferences that supplementation may be useful in prostate cancer prevention (there was a link for that, which I didn't explore). That article did not mention ALA at all. Ongoing research into DHA and related compounds would appear to make this and related compounds rather dynamic. Keeping this article up to date and factual may be somewhat challenging, as much of it is seems to be based on what is currently being researched, rather than what is currently known. A very interesting compound though. Lcph88 (talk) 23:22, 2 March 2008 (UTC)

[edit] Autism??

This article should have some reference to reduced levels of DHA observed in autistic patients, as shown in studies by Bell (2004); Vancassel (2001); Clark-Taylor (2004), and the benefits of DHA supplementation shown by Amminger (2007). The mechanism is unknown as yet, but there is clearly a correlation of some sort. I will add this section in a week or so if it hasn't been done by then (when I've finished my report on it!) Virtualt333 (talk) 16:33, 6 June 2008 (UTC)