Talk:Docosahexaenoic acid

Mechanisms

This article could strongly benefit from the inclusion of molecular mechanisms under the health benefits section. This would include its absorption in the lipid membrane; modulation of the AA cascade resulting in anti-inflammatory response; metabolism toward resolvin and neuroprotectins that contribute to cardiac function; modulation of vascular flow by upregulating expression of nitric synthase; reduction in TAGS; and strong control of NDP1. Will do it myself in a few weeks if no one can be bothered.

Untitled

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

**Confusion about IUPAC name**

What is going on: why is it DocosAhexaenoic acid?

Where is the extra "A" coming from?

IUPAC rules are that an A becomes an E if there are double bonds.

See: pentane --> pentene butanoic acid --> butenoic acid octadecanoic acid --> octadecenoic acid (for oleic acid, 18:1).

So, why is it not Docoshexenoic acid, as the rules indicate it should be (it comes from docosane, C22)?

Does it have to do with the harsh SH sound, which people avoided by putting an A in there?

99.251.82.235 (talk) 20:28, 12 April 2009 (UTC)

The "a" is not dropped when there is a prefix indicating multiple double bonds. For example, butane -> butene but butAdiene. Hexanoic acid -> hexenoic acid but hexAdienoic acid. Etc. --Itub (talk) 15:57, 19 August 2009 (UTC)

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.

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

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)

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)

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)

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)

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)

---

This might be useful. There is this vegan website: http://www.vegsource.com/news/2010/11/study-vegans-have-more-dha-and-omega-3-than-fish-eaters.html that has a link to a seafood company website with interesting information about it: http://newsletter.vitalchoice.com/e_article001932826.cfm?x=b11,0,w

it says: "The average EPA level in fish eaters was 64.7 micromoles per liter, compared with 57.1, 55.1, and 50 micromoles per liter for non-fish-eating meat-eaters, vegetarians, or vegans, respectively. Meanwhile, the average DHA level in fish eaters was 271 micromoles per liter, compared with 241.3, 223.5, and 286.4 micromoles per liter for non-fish-eating meat-eaters, vegetarians, or vegans, respectively."

is it a trustful source? Arthurfragoso (talk) 20:01, 11 December 2011 (UTC)

I found the medical article: doi: doi:10.3945/ajcn.2010.29457 and PMID 20861171 --Arthurfragoso (talk) 16:29, 31 December 2011 (UTC)

I just added the study to the article:

--
Although another study showed that those who don't get enough DHA or no DHA (vegans) had a higher conversion ratio of ALA to EPA and DHA, women showed an even higher ratio of conversion. The study participants who had intake of DHA and those who don't (vegans) ended up having about the same amount of EPA and DHA plasma concentration.

Reference: Welch, Ailsa A (September 22, 2010). "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 α-linolenic acid to long-chain n−3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort". The American Journal of Clinical Nutrition. 92 (5): 1040–1051. doi:10.3945/ajcn.2010.29457. PMID 20861171. {{cite journal}}: |access-date= requires |url= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help); Unknown parameter |month= ignored (help)CS1 maint: date and year (link)
--
--Arthurfragoso (talk) 23:08, 1 January 2012 (UTC)

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)

- That is a side area that has not been well studied, nor is there a clear mechanistic argument. n-3 Fa's have been studied in relation to thousands of things, and it is far beyond the scope of any wiki to present all but the primary and most well documented areas.

Errors, misstatements

The current form of this article includes:

"Of all the fatty acids, DHA has the largest effect on brain PUFA composition.[6] DHA is found in three phospholipids: phosphatidylethanolamine, ethanolamine plasmalogens, and phosphatidylserine (PS)."

However, the first sentence makes no sense while the second is an outright error. There certainly is DHA in PG, PI, PA, and PC lipids, as well as cardiolipins. I'll fix it when I get a chance. —Preceding unsigned comment added by Verytas (talk • contribs) 04:07, 6 June 2009 (UTC)

This article is so full of BS, but I couldn't help at least addressing this one:

"DHA is the most abundant omega 3 fatty acid (polyunsaturated fatty acids, PUFAs) in the brain and retina."

PUFA ≠ omega 3. Omega-3 is a kind of polyunsaturated fat. This mistake renders the whole paragraph unintelligible, because you don't even know which (if either) is correct.--65.0.192.82 (talk) 11:05, 28 June 2010 (UTC)

Agree with 65.0.192.82! I just did some editing to remove and correct some of the more egregious errors (including the subsection on sustainable sources of DHA, which seemed to be more about toxins than DHA). However, many remain and overall this remains a very poor article. Verytas (talk) 11:33, 30 June 2011 (UTC)

Misinterpretation of a study:

"For example, one study[49] found that the use of DHA-rich fish oil capsules did not reduce postpartum depression in mothers or improve cognitive and language development in their offspring during early childhood."

What the article actually said

"Efficacy The percentage of women reporting high levels of depressive symptoms (EPDS score >12) during the first 6 months postpartum did not differ between the DHA and control groups (9.67% vs 11.19%; adjusted RR, 0.85; 95% CI, 0.70-1.02; P = .09) (Table 2). Depressive symptoms were more common among women with a previous or current diagnosis of depression at trial entry but did not differ between groups. The percentage of women with a new medical diagnosis for depression during the trial or a diagnosis requiring treatment also did not differ between groups."

Note that the sudy found a 15% reduction in those with depressive scores, but the P level of 9% barely failed significance. That is, the study provides evidence, though not conclusive evidence, that DHA helps with post-natal depression.

Suggest the wording be changed as follows:

"One study[49] suggested, but at P=0.09 fell short of statistical significance, that the use of DHA-rich fish oil capsules did not reduce postpartum depression in mothers or and found no evidence that it improves cognitive and language development in their offspring during early childhood." —The Preceding unsigned comment added by 121.217.201.172 (contribs) 04:07, 6 June 2009 (UTC)

I concur, the study does not definitively show what is stated in the article. DeadFire999 (talk) 06:12, 2 June 2015 (UTC)

Serotonin

This, this and this support DHA's relation to serotonin. "5-HT receptors are known to be modified by omega-3 fatty acids." There are also several articles on pubmed (look at "related articles" in the last link of the three) explaining that omega-3 can be used to treat schizophrenia (and psychosis). MichaelExe (talk) 21:50, 7 September 2009 (UTC)

Sources

I've done some fixing of the LEDE/LEAD, which gave a false impression. While it is true that microalgae are the ultimate source of most DHA in oceanic animals, that simply is NOT true of land animals that live far enough inland to get no seafood. The deer in the forests of Colorado has a brain high in DHA (and a fair amount of it in body fat) but NONE of it comes from microalgae. The deer makes it from ALA made by the plants it eats. Vegan humans make it the same way. SBHarris 18:30, 24 August 2010 (UTC)

Humans cannot convert ALA to DHA in the same ratio that other mammals can regardless of vegetarian or vegan status. The average conversion rate is less than 5% for males and only slightly higher for females. Please provide source of Colorado deer ALA to DHA conversion example. — Preceding unsigned comment added by MBC2011 (talk • contribs) 18:28, 6 July 2011 (UTC)

DHA is bad for you (metastudy)

--Regarding the possible reasons why EPA and not DHA may be more effective in depression, there is increasing evidence that DHA supplementation may have damaging effects on the nervous system. DHA, the most highly unsaturated ω3 LC-PUFA in the body, is very susceptible to lipid peroxidation and can damage DNA [84], increase production of reactive oxygen species in glial cells [85], and worsen neurologic state in rat perfusion-injury models [86]. Highly reactive A4/J4 neuroprostanes produced from DHA in vivo under conditions of oxidative stress [87] may explain some of the above negative findings. In addition, although retro-conversion of DHA to EPA can occur to a certain extent, DHA is at the end of the biosynthetic pathway of ω3 LC-PUFAs and therefore supplementation may boost DHA to levels that cannot be adequately handled by metabolic pathways, which in turn, may further exacerbate production of damaging reactive derivatives. It is noteworthy that under normal circumstances, the rate of conversion of dietary α-linolenic acid to DHA is about 1% [88] and daily turnover of DHA in the adult human brain is only 4.6 mg [89], suggesting that it may not be desirable to boost DHA levels to such an extent as occurs during supplementation [82].

http://www.jacn.org/content/28/5/525.full — Preceding unsigned comment added by 71.194.190.179 (talk) 06:00, 11 December 2011 (UTC)

Should be mentioned in the article ? (or was it, and then deleted ?) - Rod57 (talk) 08:43, 3 May 2016 (UTC)

Now this was interesting information! Any new information? The comment was written in 2011.

I am not an expert in this EPA/DHA/α-linolenic acid thing, but this is what I currently do. I am ready to change my habbits if anyone says this is not optimal for health:

• 1700mg of EPA a day from softgels. No DHA from any food. I hope RBC=Red Blood Cell DHA correlates well with brain DHA?? Any animal studies about this? My RBC blood test claims I have a good EPA/DHA ratio even when eating no DHA.
• 1-2 tablespoons a day extra virgin hemp oil.
• 1-2 tablespoons a day extra virgin olive oil
• 150-300 grams a day roasted nut mix including about 5 different nuts. (Roasted, but not a signicant source of trans fats, because my fatty acid RBC blood test found almost no trans fats).
• Berry fats for berry powders, like omega-7 (berry seeds have some fat). — Preceding unsigned comment added by 91.155.24.127 (talk) 11:25, 8 April 2017 (UTC)

I follow my RBC = Red Blood Cell fatty acids, it is possible to measure at least about 20 fatty acids from RBC. (One can also measure at least about 10 minerals from RBC! I don't much yet about optimal RBC mineral amounts, perhaps the ratios are most important like zinc/copper ratio)

Background info: I am a healty 40 year white=caucasian male with blue eyes, 180cm/70kg so about average size for a man with low body fat. 23andme gene test says I am at least 98% Finnish. Apoe4 gene shows I have a very low alzheimer risk and I take a lot of supplements that reduce Alzheimer risk, so Alzheimer is not my main concern. What I would like to do is reduce stress-related aggression & hostility.

91.155.24.127 (talk) 11:13, 8 April 2017 (UTC)

Studies of vegetarians and vegans - apparent contradiction

In the first paragraph, there's written that "Vegetarians and vegans have substantially lower levels of DHA in their bodies". However, the second paragraph reads "In a study of over 14,000 men and women, vegans with no intake of dietary EPA or DHA still had very high levels of plasma DHA" and "Male vegans had only slightly lower levels of DHA […] than fish-eaters". Does it mean that the cited studies lead to contradictory results, or should one of the paragraphs be reworded (perhaps by changing or omitting the word "substantially" in the first one or "slightly" in the second one)? 90.176.211.48 (talk) 13:24, 1 March 2012 (UTC)

              Vegans and vegetarians consumes a lot of ALA from which DHA is later produced in large quantities, so meat-eaters are depleted of DHA, not vegans or vegetarians

-DHA is not produced in 'large quantities' from ALA. The biosynthesis pathway incorporates DHA and EPA production, and the ratio between them is species limited. Humans make extremely low levels of DHA compared to EPA from an ALA precursor (about 1:15, compared to the 1:4 thought to be optimal) - hence why there is argument for fish oil supplementation to begin with (otherwise why bother?)

Furthermore, much of this page seems pretty poorly informed, and I might just do a massive scrap/rewrite when I have time - at least as concerns the biology/health benefits side of things.

Assessment comment from Nov 2007

The comment(s) below were originally left at Talk:Docosahexaenoic acid/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Comment(s)

Press [show] to view →

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.

Last edited at 22:53, 5 November 2007 (UTC). Substituted at 13:33, 29 April 2016 (UTC)

Need a section on how it is metabolised eg to EDPs

We need a section on how it is metabolised, eg. by CYP2C9..., where, at what rate, and to what. eg. CYP2C9 says "It likewise metablizes docosahexaenoic acid to epoxydocosapentaenoic acids (EDPs; primarily 19,20-epoxy-eicosapentaenoic acid isomers [i.e. 10,11-EDPs]) " ... I'll start one. - Rod57 (talk) 08:25, 3 May 2016 (UTC)

What are normal and deficient plasma DHA levels

Article mentions levels and deficiency but doesn't say what they are [numerically], or how they are tested. - Rod57 (talk) 08:39, 3 May 2016 (UTC)

'Vegan/vegetarian study' comment above (Dec 2011) above says " the average DHA level in fish eaters was 271 micromoles per liter, compared with 241.3, 223.5, and 286.4 micromoles per liter for non-fish-eating meat-eaters, vegetarians, or vegans, respectively." with source. - Rod57 (talk) 13:32, 3 May 2016 (UTC)

Seems to counteract the epigenetic effects of fructose in rats

DHA seems to counteract the [bad] epigenetic effects of fructose in rats says : Fructose Disrupts Brain Gene Networks, Omega-3 Restores Them. April 2016 - Rod57 (talk) 13:30, 3 May 2016 (UTC)

They gave rats only huge amounts fructose and DHA. They did not test is sufficient EPA enough. EPA converts to DHA.

91.155.24.127 (talk) 11:32, 8 April 2017 (UTC)

Toxicology in fish oil

Tardispower added this content below which I removed with the edit comment: "rv unsourced; rv "brain damage" content & ref not stated in the article and not confirmed; rv PCB statement which is not confirmed as toxic in supplements"

Tardispower's edit: "However, fish oil supplement manufacturing introduces considerable amounts of PCBs and other pollutants to such an extent that the recommended daily dosages would exceed the tolerable daily intake of toxicity.PMID 20692313

The PCB comment has two issues: 1) it does not state that all fish oil supplements are contaminated with PCBs; 2) it does not state that DHA levels in the supplement would be affected if PCBs were present, and that if PCBs were present, the daily intake ceiling for DHA would be affected. This is unclear reasoning and there are no data to support such a statement.

Tardispower's further comment: "I noticed that Zefr removed my edits on this page. You will note that while claiming that what I wrote in the article was "unsourced", despite the citation which clearly makes it sourced, you have kept the primary studies which are in favour of fish oils in the paragraph below. I would also note that Polychlorinated biphenyl are definitely considered a toxic substance. The toxicology report cited focuses solely on supplements, which counters your comment "PCB statement which is not confirmed as toxic in supplements." I would also recommend going over the PCB page to actually see how it has been proven to be a toxic compound. In the future, I recommend that we use the talk page where significant and important information can be discussed and shaped without outright removing it since the citations I made meet the notability and reliable source criteria. I urge the user to use this page to discuss further and clearly justify the removal of what the user calls unsourced claims."Tardispower (talk) 14:41, 13 October 2016 (UTC)

Tardispower also wrote that "brain damage" resulted from consuming contaminated fish oil by this edit and this source, PMID 22079313. That is not what the source reported (a study of IQ decreases) and the source has not been confirmed by more substantial numbers of subjects in a more rigorous clinical trial design; this source is WP:PRIMARY and is not useable for these claims. --Zefr (talk) 15:00, 13 October 2016 (UTC)

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Helical structure when in membrane's bilayer

it forms not a ring, but linear helix and in this way forms or fits into a membrane making it very fluid and very flexible and still very strong (gum-like) without even cholesterol which helps DHA to act as an anti-aging agent

Mention what it looks like

Say if in its pure state is is hard, soft, green, blue, etc. Jidanni (talk) 03:34, 18 February 2019 (UTC)

Scientific fraud

See here. Count Iblis (talk) 12:09, 29 August 2019 (UTC)