fbpx
Wikipedia

Conjugated linoleic acid

February 15, 2024

Conjugated linoleic acids (CLA) are a family of isomers of linoleic acid. In principle, 28 isomers are possible. CLA is found mostly in the meat and dairy products derived from ruminants. The two C=C double bonds are conjugated (i.e., separated by a single bond). CLAs can be either cis-fats or trans-fats.

Rumenic acid, an example of conjugated linoleic acid

CLA is marketed as a dietary supplement on the basis of its supposed health benefits.[1]

Biochemistry edit

CLA describes a variety of isomers of octadecadienoic fatty acids.[2]

Commonly, CLAs are studied as some mixture of isomers wherein the isomers c9,t11-CLA (rumenic acid) and t10,c12-CLA were the most abundant.[3] Studies show however that individual isomers have distinct health effects.[4][5]

Conjugated linoleic acid is both a trans fatty acid and a cis fatty acid. The cis bond causes a lower melting point and, ostensibly, also the observed beneficial health effects. Unlike other trans fatty acids, it may have beneficial effects on human health.[6] CLA is conjugated, and in the United States, trans linkages in a conjugated system are not counted as trans fats for the purposes of nutritional regulations and labeling.[citation needed] CLA and some trans isomers of oleic acid are produced by microorganisms in the rumens of ruminants. Non-ruminants, including humans, produce certain isomers of CLA from trans isomers of oleic acid, such as vaccenic acid, which is converted to CLA by delta-9-desaturase.[7][8]

In healthy humans, CLA and the related conjugated linolenic acid (CLNA) isomers are bioconverted from linoleic acid and alpha-linolenic acid, respectively, mainly by Bifidobacterium bacteria strains inhabiting the gastrointestinal tract.[citation needed] However, this bioconversion may not occur at any significant level in those with a digestive disease, gluten sensitivity, or dysbiosis.[9][10][11][12]

Health effects edit

CLA is marketed in dietary supplement form for its supposed anti-cancer benefit (for which there is no strong evidence or known mechanism, and very few studies conducted so far)[13] and as a bodybuilding aid.[1] A 2004 review of the evidence said that while CLA seemed to benefit animals, there was a lack of good evidence of human health benefits despite the many claims made for it.[14]

Likewise, there is insufficient evidence that CLA has a useful benefit for overweight or obese people as it has no long-term effect on body composition.[15] Although CLA has shown an effect on insulin response in diabetic rats, there is no evidence of this effect in humans.[16]

Dietary sources edit

Food products from grass-fed ruminants (e.g. mutton and beef) are good sources of CLA and contain much more of it than those from grain-fed animals.[17] Eggs from chickens that have been fed CLA are also rich in CLA, and CLA in egg yolks has been shown to survive the temperatures encountered during frying.[18] Some mushrooms, such as Agaricus bisporus and Agaricus subrufescens, are rare non-animal sources of CLA.[19][20]

However, dietary punicic acid—which is abundant in pomegranate seeds—is converted to the CLA rumenic acid upon absorption in rats,[21] suggesting that non-animal sources can still effectively provide dietary CLA.

History edit

In 1979 CLAs were found to inhibit chemically-induced cancer in mice [22] and research on its biological activity has continued.[23]

In 2008, the United States Food and Drug Administration categorized CLA as generally recognized as safe (GRAS).[24]

See also edit

References edit

  1. ^ a b Talbott SM, Hughes K (2007). "Conjugated linoleic acid". The Health Professional's Guide to Dietary Supplements. Lippincott Williams & Wilkins. pp. 14–. ISBN 978-0-7817-4672-4.
  2. ^ Weiss, M.F.; Martz, F.A.; Lorenzen, C.L. (2004-04-01). "REVIEWS: Conjugated Linoleic Acid: Historical Context and Implications". The Professional Animal Scientist. 20 (2): 127–135. doi:10.15232/S1080-7446(15)31287-0. ISSN 1080-7446.
  3. ^ "Fatty Acid Profiles of Liver, Adipose Tissue, Speen, and Heart of Mice Fed Diets Containing T10, C-12-, and C9, T11-Conjugated Linoleic Adic". from the original on 2007-03-01.
  4. ^ Tricon S, Burdge GC, Kew S, et al. (September 2004). "Opposing effects of cis-9,trans-11 and trans-10,cis-12 conjugated linoleic acid on blood lipids in most healthy humans". Am. J. Clin. Nutr. 80 (3): 614–20. doi:10.1093/ajcn/80.3.614. PMID 15321800.
  5. ^ Ulf Risérus, MMed; Samar Basu; Stefan Jovinge, MD; Gunilla Nordin Fredrikson; Johan Ärnlöv, MD; Bengt Vessby, MD (September 2002). "Supplementation With Conjugated Linoleic Acid Causes Isomer-Dependent Oxidative Stress and Elevated C-Reactive Protein". Circulation. 106 (15): 1925–9. doi:10.1161/01.CIR.0000033589.15413.48. PMID 12370214. 01.CIR.0000033589.15413.48v1. from the original on 2007-02-28. Retrieved 2007-02-19.
  6. ^ . Dairy Council. Archived from the original on 8 August 2016. Retrieved 23 April 2018.
  7. ^ Kuhnt K, Kraft J, Moeckel P, Jahreis G (April 2006). "Trans-11-18 : 1 is effectively Delta9-desaturated compared with trans-12-18 : 1 in humans". Br J Nutr. 95 (4): 752–761. doi:10.1079/BJN20051680. PMID 16571155.
  8. ^ Banni S, Angioni E, Murru E, Carta G, Melis M, Bauman D, Dong Y, Ip C (2001). "Vaccenic acid feeding increases tissue levels of conjugated linoleic acid and suppresses development of premalignant lesions in rat mammary gland". Nutr Cancer. 41 (1–2): 91–7. doi:10.1080/01635581.2001.9680617. PMID 12094634. S2CID 2920114.
  9. ^ Estelle Devillard; Freda M. McIntosh; Sylvia H. Duncan; R. John Wallace (March 2007). "Metabolism of Linoleic Acid by Human Gut Bacteria: Different Routes for Biosynthesis of Conjugated Linoleic Acid". Journal of Bacteriology. 189 (6): 2566–2570. doi:10.1128/JB.01359-06. PMC 1899373. PMID 17209019.
  10. ^ E. Barrett; R. P. Ross; G. F. Fitzgerald; and C. Stanton (April 2007). "Rapid Screening Method for Analyzing the Conjugated Linoleic Acid Production Capabilities of Bacterial Cultures". Applied and Environmental Microbiology. 73 (7): 2333–2337. Bibcode:2007ApEnM..73.2333B. doi:10.1128/AEM.01855-06. PMC 1855641. PMID 17277221.
  11. ^ Gorissen L, De Vuyst L, Raes K, De Smet S, Leroy F (April 2012). "Conjugated linoleic and linolenic acid production kinetics by bifidobacteria differ among strains". International Journal of Food Microbiology. 155 (3): 234–240. doi:10.1016/j.ijfoodmicro.2012.02.012. PMID 22405353.
  12. ^ Esther Jiméneza; M. Antonia Villar-Tajadurab; María Marína; Javier Fontechab; Teresa Requenac; Rebeca Arroyoa; Leónides Fernándeza; Juan M. Rodrígueza (July 2012). "Complete Genome Sequence of Bifidobacterium breve CECT 7263, a Strain Isolated from Human Milk" (PDF). Journal of Bacteriology. 194 (14): 3762–3763. doi:10.1128/JB.00691-12. PMC 3393482. PMID 22740680.
  13. ^ Ochoa JJ, Farquharson AJ, Grant I, Moffat LE, Heys SD, Wahle KW (2004). "Conjugated linoleic acids (CLAs) decrease prostate cancer cell proliferation: different molecular mechanisms for cis-9, trans-11 and trans-10, cis-12 isomers". Carcinogenesis. 25 (7): 1185–91. doi:10.1093/carcin/bgh116. PMID 14976130.
  14. ^ Rainer L, Heiss CJ (June 2004). "Conjugated linoleic acid: health implications and effects on body composition". J Am Diet Assoc (Review). 104 (6): 963–. doi:10.1016/j.jada.2004.03.016. PMID 15175596.
  15. ^ Onakpoya IJ, Posadzki PP, Watson LK, Davies LA, Ernst E (March 2012). "The efficacy of long-term conjugated linoleic acid (CLA) supplementation on body composition in overweight and obese individuals: a systematic review and meta-analysis of randomized clinical trials". Eur J Nutr (Systematic review). 51 (2): 127–34. doi:10.1007/s00394-011-0253-9. PMID 21990002. S2CID 39625058.
  16. ^ Davì G, Santilli F, Patrono C (August 2010). "Nutraceuticals in diabetes and metabolic syndrome". Cardiovascular Therapeutics (Review). 28 (4): 216–26. doi:10.1111/j.1755-5922.2010.00179.x. PMID 20633024.
  17. ^ T. R. Dhiman; L. D. Satter; M. W. Pariza; M. P. Galli; K. Albright; M. X. Tolosa (1 May 2000). "Conjugated Linoleic Acid (CLA) Content of Milk from Cows Offered Diets Rich in Linoleic and Linolenic Acid". Journal of Dairy Science. 83 (5): 1016–1027. doi:10.3168/jds.S0022-0302(00)74966-6. PMID 10821577. Retrieved 2006-05-27.
  18. ^ Lin Yang; Ying Cao; Zhen-Yu Chen (2004). "Stability of conjugated linoleic acid isomers in egg yolk lipids during frying". Food Chemistry. Elsevier. 86 (4): 531–535. doi:10.1016/j.foodchem.2003.09.006.
  19. ^ Chen, S.; Oh, SR; Phung, S; Hur, G; Ye, JJ; Kwok, SL; Shrode, GE; Belury, M; et al. (2006). "Anti-aromatase activity of phytochemicals in white button mushrooms (Agaricus bisporus)". Cancer Res. 66 (24): 12026–12034. doi:10.1158/0008-5472.CAN-06-2206. PMID 17178902.
  20. ^ W. J. Jang S. W. Hyung. . Division of Applied Life Science (BK21), Graduate School, Gyeongsang National University, Jinju, 660-701, South Korea. Archived from the original on 2010-05-04. {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: location (link)
  21. ^ Tsuzuki T, Kawakami Y, Abe R (1 August 2006). "Conjugated linolenic acid is slowly absorbed in rat intestine, but quickly converted to conjugated linoleic acid". J Nutr. 136 (8): 2153–9. doi:10.1093/jn/136.8.2153. PMID 16857834. Retrieved 2007-01-23.
  22. ^ Ha YL, Grimm NK, Pariza MW (1987). "Anticarcinogens from fried ground beef: heat-altered derivatives of linoleic acid". Carcinogenesis. 8 (12): 1881–7. doi:10.1093/carcin/8.12.1881. PMID 3119246.
  23. ^ Pariza MW (June 2004). "Perspective on the safety and effectiveness of conjugated linoleic acid". Am. J. Clin. Nutr. 79 (6 Suppl): 1132S–1136S. doi:10.1093/ajcn/79.6.1132S. PMID 15159246.
  24. ^ "CLA approved as food ingredient". University of Wisconsin Madison. July 25, 2008. from the original on June 30, 2015. On July 24, the U.S. Food and Drug Administration announced its finding that conjugated linoleic acid, known as CLA, is "generally regarded as safe" for use in foods

February 15, 2024
conjugated, linoleic, acid, family, isomers, linoleic, acid, principle, isomers, possible, found, mostly, meat, dairy, products, derived, from, ruminants, double, bonds, conjugated, separated, single, bond, clas, either, fats, trans, fats, rumenic, acid, examp. Conjugated linoleic acids CLA are a family of isomers of linoleic acid In principle 28 isomers are possible CLA is found mostly in the meat and dairy products derived from ruminants The two C C double bonds are conjugated i e separated by a single bond CLAs can be either cis fats or trans fats Rumenic acid an example of conjugated linoleic acidCLA is marketed as a dietary supplement on the basis of its supposed health benefits 1 Contents 1 Biochemistry 2 Health effects 3 Dietary sources 4 History 5 See also 6 ReferencesBiochemistry editCLA describes a variety of isomers of octadecadienoic fatty acids 2 Commonly CLAs are studied as some mixture of isomers wherein the isomers c9 t11 CLA rumenic acid and t10 c12 CLA were the most abundant 3 Studies show however that individual isomers have distinct health effects 4 5 Conjugated linoleic acid is both a trans fatty acid and a cis fatty acid The cis bond causes a lower melting point and ostensibly also the observed beneficial health effects Unlike other trans fatty acids it may have beneficial effects on human health 6 CLA is conjugated and in the United States trans linkages in a conjugated system are not counted as trans fats for the purposes of nutritional regulations and labeling citation needed CLA and some trans isomers of oleic acid are produced by microorganisms in the rumens of ruminants Non ruminants including humans produce certain isomers of CLA from trans isomers of oleic acid such as vaccenic acid which is converted to CLA by delta 9 desaturase 7 8 In healthy humans CLA and the related conjugated linolenic acid CLNA isomers are bioconverted from linoleic acid and alpha linolenic acid respectively mainly by Bifidobacterium bacteria strains inhabiting the gastrointestinal tract citation needed However this bioconversion may not occur at any significant level in those with a digestive disease gluten sensitivity or dysbiosis 9 10 11 12 Health effects editCLA is marketed in dietary supplement form for its supposed anti cancer benefit for which there is no strong evidence or known mechanism and very few studies conducted so far 13 and as a bodybuilding aid 1 A 2004 review of the evidence said that while CLA seemed to benefit animals there was a lack of good evidence of human health benefits despite the many claims made for it 14 Likewise there is insufficient evidence that CLA has a useful benefit for overweight or obese people as it has no long term effect on body composition 15 Although CLA has shown an effect on insulin response in diabetic rats there is no evidence of this effect in humans 16 Dietary sources editFood products from grass fed ruminants e g mutton and beef are good sources of CLA and contain much more of it than those from grain fed animals 17 Eggs from chickens that have been fed CLA are also rich in CLA and CLA in egg yolks has been shown to survive the temperatures encountered during frying 18 Some mushrooms such as Agaricus bisporus and Agaricus subrufescens are rare non animal sources of CLA 19 20 However dietary punicic acid which is abundant in pomegranate seeds is converted to the CLA rumenic acid upon absorption in rats 21 suggesting that non animal sources can still effectively provide dietary CLA History editIn 1979 CLAs were found to inhibit chemically induced cancer in mice 22 and research on its biological activity has continued 23 In 2008 the United States Food and Drug Administration categorized CLA as generally recognized as safe GRAS 24 See also editConjugated fatty acidsReferences edit a b Talbott SM Hughes K 2007 Conjugated linoleic acid The Health Professional s Guide to Dietary Supplements Lippincott Williams amp Wilkins pp 14 ISBN 978 0 7817 4672 4 Weiss M F Martz F A Lorenzen C L 2004 04 01 REVIEWS Conjugated Linoleic Acid Historical Context and Implications The Professional Animal Scientist 20 2 127 135 doi 10 15232 S1080 7446 15 31287 0 ISSN 1080 7446 Fatty Acid Profiles of Liver Adipose Tissue Speen and Heart of Mice Fed Diets Containing T10 C 12 and C9 T11 Conjugated Linoleic Adic Archived from the original on 2007 03 01 Tricon S Burdge GC Kew S et al September 2004 Opposing effects of cis 9 trans 11 and trans 10 cis 12 conjugated linoleic acid on blood lipids in most healthy humans Am J Clin Nutr 80 3 614 20 doi 10 1093 ajcn 80 3 614 PMID 15321800 Ulf Riserus MMed Samar Basu Stefan Jovinge MD Gunilla Nordin Fredrikson Johan Arnlov MD Bengt Vessby MD September 2002 Supplementation With Conjugated Linoleic Acid Causes Isomer Dependent Oxidative Stress and Elevated C Reactive Protein Circulation 106 15 1925 9 doi 10 1161 01 CIR 0000033589 15413 48 PMID 12370214 01 CIR 0000033589 15413 48v1 Archived from the original on 2007 02 28 Retrieved 2007 02 19 II International Congress on CLA from Experimental Models to Human Application Dairy Council Archived from the original on 8 August 2016 Retrieved 23 April 2018 Kuhnt K Kraft J Moeckel P Jahreis G April 2006 Trans 11 18 1 is effectively Delta9 desaturated compared with trans 12 18 1 in humans Br J Nutr 95 4 752 761 doi 10 1079 BJN20051680 PMID 16571155 Banni S Angioni E Murru E Carta G Melis M Bauman D Dong Y Ip C 2001 Vaccenic acid feeding increases tissue levels of conjugated linoleic acid and suppresses development of premalignant lesions in rat mammary gland Nutr Cancer 41 1 2 91 7 doi 10 1080 01635581 2001 9680617 PMID 12094634 S2CID 2920114 Estelle Devillard Freda M McIntosh Sylvia H Duncan R John Wallace March 2007 Metabolism of Linoleic Acid by Human Gut Bacteria Different Routes for Biosynthesis of Conjugated Linoleic Acid Journal of Bacteriology 189 6 2566 2570 doi 10 1128 JB 01359 06 PMC 1899373 PMID 17209019 E Barrett R P Ross G F Fitzgerald and C Stanton April 2007 Rapid Screening Method for Analyzing the Conjugated Linoleic Acid Production Capabilities of Bacterial Cultures Applied and Environmental Microbiology 73 7 2333 2337 Bibcode 2007ApEnM 73 2333B doi 10 1128 AEM 01855 06 PMC 1855641 PMID 17277221 Gorissen L De Vuyst L Raes K De Smet S Leroy F April 2012 Conjugated linoleic and linolenic acid production kinetics by bifidobacteria differ among strains International Journal of Food Microbiology 155 3 234 240 doi 10 1016 j ijfoodmicro 2012 02 012 PMID 22405353 Esther Jimeneza M Antonia Villar Tajadurab Maria Marina Javier Fontechab Teresa Requenac Rebeca Arroyoa Leonides Fernandeza Juan M Rodrigueza July 2012 Complete Genome Sequence of Bifidobacterium breve CECT 7263 a Strain Isolated from Human Milk PDF Journal of Bacteriology 194 14 3762 3763 doi 10 1128 JB 00691 12 PMC 3393482 PMID 22740680 Ochoa JJ Farquharson AJ Grant I Moffat LE Heys SD Wahle KW 2004 Conjugated linoleic acids CLAs decrease prostate cancer cell proliferation different molecular mechanisms for cis 9 trans 11 and trans 10 cis 12 isomers Carcinogenesis 25 7 1185 91 doi 10 1093 carcin bgh116 PMID 14976130 Rainer L Heiss CJ June 2004 Conjugated linoleic acid health implications and effects on body composition J Am Diet Assoc Review 104 6 963 doi 10 1016 j jada 2004 03 016 PMID 15175596 Onakpoya IJ Posadzki PP Watson LK Davies LA Ernst E March 2012 The efficacy of long term conjugated linoleic acid CLA supplementation on body composition in overweight and obese individuals a systematic review and meta analysis of randomized clinical trials Eur J Nutr Systematic review 51 2 127 34 doi 10 1007 s00394 011 0253 9 PMID 21990002 S2CID 39625058 Davi G Santilli F Patrono C August 2010 Nutraceuticals in diabetes and metabolic syndrome Cardiovascular Therapeutics Review 28 4 216 26 doi 10 1111 j 1755 5922 2010 00179 x PMID 20633024 T R Dhiman L D Satter M W Pariza M P Galli K Albright M X Tolosa 1 May 2000 Conjugated Linoleic Acid CLA Content of Milk from Cows Offered Diets Rich in Linoleic and Linolenic Acid Journal of Dairy Science 83 5 1016 1027 doi 10 3168 jds S0022 0302 00 74966 6 PMID 10821577 Retrieved 2006 05 27 Lin Yang Ying Cao Zhen Yu Chen 2004 Stability of conjugated linoleic acid isomers in egg yolk lipids during frying Food Chemistry Elsevier 86 4 531 535 doi 10 1016 j foodchem 2003 09 006 Chen S Oh SR Phung S Hur G Ye JJ Kwok SL Shrode GE Belury M et al 2006 Anti aromatase activity of phytochemicals in white button mushrooms Agaricus bisporus Cancer Res 66 24 12026 12034 doi 10 1158 0008 5472 CAN 06 2206 PMID 17178902 W J Jang S W Hyung Production of natural c9 t11 conjugated linoleic acid c9 t11 CLA by submerged liquid culture of mushrooms Division of Applied Life Science BK21 Graduate School Gyeongsang National University Jinju 660 701 South Korea Archived from the original on 2010 05 04 a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help CS1 maint location link Tsuzuki T Kawakami Y Abe R 1 August 2006 Conjugated linolenic acid is slowly absorbed in rat intestine but quickly converted to conjugated linoleic acid J Nutr 136 8 2153 9 doi 10 1093 jn 136 8 2153 PMID 16857834 Retrieved 2007 01 23 Ha YL Grimm NK Pariza MW 1987 Anticarcinogens from fried ground beef heat altered derivatives of linoleic acid Carcinogenesis 8 12 1881 7 doi 10 1093 carcin 8 12 1881 PMID 3119246 Pariza MW June 2004 Perspective on the safety and effectiveness of conjugated linoleic acid Am J Clin Nutr 79 6 Suppl 1132S 1136S doi 10 1093 ajcn 79 6 1132S PMID 15159246 CLA approved as food ingredient University of Wisconsin Madison July 25 2008 Archived from the original on June 30 2015 On July 24 the U S Food and Drug Administration announced its finding that conjugated linoleic acid known as CLA is generally regarded as safe for use in foods Retrieved from https en wikipedia org w index php title Conjugated linoleic acid amp oldid 1184150061, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.