Talk:Linoleic acid/Archive 1

Comment
The footnote giving the reference for the chemical formula was removed. Should it be reinstated, or should the footnote be removed? Ged3000 19:55, 24 January 2006 (UTC)

"Food"
This section is disorganized and somewhat confusing. I will replace the list (which I find awkward) with a table, organized by percent values (as on http://en.wikipedia.org/wiki/Alpha-Linolenic_acid). For the moment, I will not be researching any new information or adding citations. I will average ranged values (i.e. 21-33% becomes 27%) and omit sources that have no value until they can be provided at a later date (these are grain-fed cows milk, spirulina, okra and castor oil).

I will also change the title of this section to 'Dietary Sources'; 'Food' is too vague.Rhø (talk) 21:36, 21 June 2009 (UTC)

This table appears to refer to alpha linoleic acid, not linoleic acid. The two are far from equivalent. The former is an omega-3 fatty acid and the latter an omega-6. This table should be removed. —Preceding unsigned comment added by 74.95.127.189 (talk) 20:21, 27 July 2009 (UTC)

No, the table appeared to refer to ALA (&alpha;–linolenic acid) because the heading was "ALA" instead of "LA". However, the values are for linoleic acid, not &alpha;–linolenic acid. I have returned the table and corrected the heading to read "LA" instead of "ALA"   Jay L09 (talk) 18:41, 28 July 2009 (UTC)

You are correct. Thanks for clarifying. —Preceding unsigned comment added by 74.95.127.189 (talk) 22:36, 28 July 2009 (UTC)

Chemical Formula of Linoleic acid
For some reason, the Chemical Formula of Linoleic acid (and precisely calculated Molar mass) was identified (I think by an automated anti-vandal bot) to be unnecessary to the description of Linoleic acid. As it took me a good deal of time to calculate (mainly for the purpose of calculating the CO2 emissions of the acid after combustion (as in Biofuel), then for critically comparing it to other fatty acids (as a learning exercise: to further expand the info in other pages on fatty acids)), I would greatly appreciate it if this info was re-entered as I believe that it would save myself and many others a good deal of time in researching the chemistry of fatty acids in future. I hereby insert my expanded line of text preceeded by the appropriate line of comparison text: (Linoleic acid (LA) is an unsaturated omega-6 fatty acid with the molecular formula C18H32O2)( AND/OR the chemical formula CH3-CH2-CH2-CH2-CH2-CH=CH-CH2-CH=CH-CH2-CH2-CH2-CH2-CH2-CH2-CH2-COOH of Molar mass 280.44548(1724) g/mol.) P.S.  I honestly believe that this additional & precise information would be of help to students studying the chemistry of fatty acids (by reading the Wikipedia, reluctant as I am to troll the net via Google-esque search programs). If you believe that this one line of data constitutes either vandalism, or is so un-helpful, that it might as well be vandalism, then please comment thusly. Otherwise, if you might think that this data is no more un-helpful than any of the other data listed on this page (or similar pages), then please feel free to re-insert the above line. P.P.S. As I have saved my research locally, your (pending) decision doesn't really affect me much, but I would hope that my thorough attention to detail would preclude any future attempts to reverse or nullify my contributions to a community that seems centered around mutual cooperation to understand the world's detailed structures and chemistries.
 * I don't understand why it was removed either, but your contribution appeared to be very useful. I would put it back in. If the bot tries to remove it again, we should probably complain to whomever is running it. Frankg 19:21, 30 April 2006 (UTC)

Anticarcinogenic effect
User:Panos AGR has been attempting to add a reference to an article on linoleic acid as a cancer preventitive. I have had a look at the article, and it's not in a peer reviewed journal, it cites research selectively (for example saying that the effect of fibre on colon cancer is "in question", citing two studies, neither of which is a large review) and advances the Warburg hypothesis of carcinogenesis (lack of cellular oxygen). --Slashme 09:53, 7 September 2007 (UTC)

Is linoleic acid a precursor for prostaglandins?
It says on this page that linoleic acid is used in prostaglandin synthesis. I was under the impression that arachidonic acid was the main substrate for prostaglandin synthesis. Does anyone know for certain whether linoleic acid is used as well? My instinct is that it isn't a substrate, because prostaglandins are 20 carbons long and linoleic acid is only 18, so it would need to be extended before being used in prostaglandin synthesis. Can anyone comment on this?

The linoleic acid is a precursor to the arachidonic acid. DarkWolf9 (talk) 05:38, 24 October 2008 (UTC)

linoleic acid is also an alternative substrate for cyclooxygenase (PGHS), the first step in prostaglandin biosynthesis. Pelirojopajaro (talk) 02:35, 12 July 2010 (UTC)

Vasoconstrictive?
"For example, both Thrombaxane and LeukotrieneB4 are proaggretory and vasoconstrictive eicosanoids."

If Leokotriene contributes to inflammatory response, wouldn't it be vasodilative as opposed to vasoconstrictive?

Royal Wulff (talk) 08:38, 2 May 2009 (UTC)

Yes, "vasoconstrictive" is the correct word. See the abstract from the following paper:

John E. Kinsella, Belur Lokesh, and Richard A. Stone (1990) “Dietary n-3 polyunsatruated fatty acids and amelioration of cardiovascular disease: possible mechanisms.” American Journal of Clinical Nutrition. 52: 1-28.

Logan Rutherford (talk) 12:42, 7 May 2009 (ET)

More info about the dietary sources....
--222.67.208.221 (talk) 06:32, 19 May 2010 (UTC)
 * http://scholar.google.com.hk/scholar?as_q=linoleic+acid+wholemeal&num=10&btnG=Search+Scholar&as_epq=&as_oq=&as_eq=&as_occt=title&as_sauthors=&as_publication=&as_ylo=&as_yhi=&as_sdt=1.&as_sdtp=on&as_sdts=5&hl=en

Can we please find sources or delete the uncited percentages of linoleic acid? It is extremely deceiving, and I can't find sources online that concretely give evidence for these. — Preceding unsigned comment added by 165.123.239.222 (talk) 05:50, 21 February 2013 (UTC)

Clarification Needed
Alcoholic liver disease Consumption of linoleic acid facilitates the generation of alcoholic liver disease.[citation needed].

The above text appears under the head 'Possible role in diseases'

How is the above to be interpreted? Does LA help in the progression of the disease and thereby adding to the problem or does it help improve the condition and is therefore has a beneficial role.

Please clarify.

Spicierboar (talk) 14:37, 12 June 2010 (UTC)


 * Removed    Jay L09 (talk) 07:14, 15 June 2010 (UTC)

Table Reference
Does anyone have a reference for the table featuring % found in various crops? The values listed conflict with (Srivastava, A.; Prasad, R. Triglycerides-based diesel fuels. Renewable and Sustainable Energy Reviews 2000, 4, 111-133.) not that that's the best journal. Thanks.--134.20.11.89 (talk) 22:44, 18 October 2011 (UTC)

Linoleic acid is the major regulator reducing levels of "bad" low-density lipoprotein (LDL)-Cholesterol by downregulating production and enhancing clearance
[Note: emphasis below is supplied]

Wijendran V, Hayes KC.

Dietary n-6 and n-3 fatty acid balance and cardiovascular health.

Annu Rev Nutr. 2004;24:597-615.

Abstract

Epidemiological and clinical studies have established that the n-6 fatty acid, linoleic acid (LA), and the n-3 fatty acids, linolenic acid (LNA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) collectively protect against coronary heart disease (CHD). LA is the major dietary fatty acid regulating low-density lipoprotein (LDL)-C metabolism by downregulating LDL-C production and enhancing its clearance. Further, the available mass of LA is a critical factor determining the hyperlipemic effects of other dietary fat components, such as saturated and trans fatty acids, as well as cholesterol. By contrast, n-3 fatty acids, especially EPA and DHA, are potent antiarryhthmic agents. EPA and DHA also improve vascular endothelial function and help lower blood pressure, platelet sensitivity, and the serum triglyceride level. The distinct functions of these two families make the balance between dietary n-6 and n-3 fatty acids an important consideration influencing cardiovascular health. Based on published literature describing practical dietary intakes, we suggest that consumption of ~6% en LA, 0.75% en LNA, and 0.25% en EPA + DHA represents adequate and achievable intakes for most healthy adults. This corresponds to an n-6/n-3 ratio of ~6:1. However, the absolute mass of essential fatty acids consumed, rather than their n-6/n-3 ratio, should be the first consideration when contemplating lifelong dietary habits affecting cardiovascular benefit from their intake.

Source

Foster Biomedical Research Lab, Brandeis University, Waltham, Massachusetts 02254, USA. vwijen@brandeis.edu — Preceding unsigned comment added by Ocdnctx (talk • contribs) 02:49, 25 November 2011 (UTC)

Linoleic acid is the major regulator reducing levels of "bad" low-density lipoprotein (LDL)-Cholesterol by downregulating production and enhancing clearance
[Note: emphasis below is supplied]

Wijendran V, Hayes KC.

Dietary n-6 and n-3 fatty acid balance and cardiovascular health.

Annu Rev Nutr. 2004;24:597-615.

Abstract

Epidemiological and clinical studies have established that the n-6 fatty acid, linoleic acid (LA), and the n-3 fatty acids, linolenic acid (LNA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) collectively protect against coronary heart disease (CHD). LA is the major dietary fatty acid regulating low-density lipoprotein (LDL)-C metabolism by downregulating LDL-C production and enhancing its clearance. Further, the available mass of LA is a critical factor determining the hyperlipemic effects of other dietary fat components, such as saturated and trans fatty acids, as well as cholesterol. By contrast, n-3 fatty acids, especially EPA and DHA, are potent antiarryhthmic agents. EPA and DHA also improve vascular endothelial function and help lower blood pressure, platelet sensitivity, and the serum triglyceride level. The distinct functions of these two families make the balance between dietary n-6 and n-3 fatty acids an important consideration influencing cardiovascular health. Based on published literature describing practical dietary intakes, we suggest that consumption of ~6% en LA, 0.75% en LNA, and 0.25% en EPA + DHA represents adequate and achievable intakes for most healthy adults. This corresponds to an n-6/n-3 ratio of ~6:1. However, the absolute mass of essential fatty acids consumed, rather than their n-6/n-3 ratio, should be the first consideration when contemplating lifelong dietary habits affecting cardiovascular benefit from their intake.

Source

Foster Biomedical Research Lab, Brandeis University, brandeis.edu Waltham, Massachusetts 02254, USA. vwijen corresponding author Ocdnctx (talk) 02:51, 25 November 2011 (UTC)

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Large literature on this compound
According to Chemical Abstracts Service: get references (87819)>refine "Review" (857)>refine "2000-" (666). Since the year 2000, 8 publications and reports appear daily on this compound. --Smokefoot (talk) 23:47, 5 August 2019 (UTC)

Lipid Numbers
Why is it 18:2 cis-9,12 (IUPAC numbers) and not something like 18:2 cis-6,9 (omega-numbers)?

Simon de Danser (talk) 07:23, 7 November 2020 (UTC)

various problems
with structure HO(O=)C-(CH2)7CH=CH-CH2-CH=CH-(CH2-)3H - should the final - (in (CH2-) be deleted?

Metabolism - For example, both AA-derived thrombaxane?

The oxidized metabolic products of linoleic acid, such as 9-hydroxyoctadecanoic acid and 13-hydroxyoctadecanoic acid - these are reduced (& hydrated) rather than oxidized (should they be hydroxyoctadecadienoic instead?)

to their keto metabolites, 13-oxo-octadecadienoic acid and 9-oxo-octadecdienoic? acid

Dietary sources - Hemp oil is out of order (54.3%) 71.163.180.156 (talk) 08:02, 10 November 2020 (UTC)

Brazil nuts
The wikipedia article on Brazil nuts says they are high in linoleic acid, but they don't appear in the table. Is there a reason for this?

Fustbariclation (talk) 09:44, 17 September 2023 (UTC)

Omega numbering in illustration
https://en.wikipedia.org/wiki/Fatty_acid#Nomenclature seems to say the omega-6 carbon is the same as the alpha-12 carbon. Yellowdesk60 (talk) 04:16, 28 December 2021 (UTC)

IP claiming conflict of interest
This edit by an claimed removed a review, and claimed it is "a study with conflict of interest - The California Walnut Association is a benefactor highly interested in positive claims about nut and seed oils' positive health benefits". However, the review was not funded by the California Walnut Association, nor any other nut company. The paper was not industry funded. The review received funding from the American Diabetes Association Fellowship Award. The review was co-written by Frank Hu. Psychologist Guy (talk) 16:03, 10 January 2023 (UTC)