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| PMID 9733537</ref> Erucic acid is broken down into shorter-chain fatty acids in the human liver by the long-chain ] ]. | PMID 9733537</ref> Erucic acid is broken down into shorter-chain fatty acids in the human liver by the long-chain ] ]. | ||
| == Health concerns == | |||
| == Health effects == | == Health effects == | ||
| Epidemiological studies suggest that, in regions where mustard oil is still used in a traditional manner, mustard oil may afford some protection against cardiovascular diseases. In this sense 'traditional' means that (a) the oil is used fresh and (b) vegetable fats count only as a small percentage of the total caloric intake. Whether this effect is due to the nature of erucic acid ''per se'' to make the blood platelets less sticky, or to the presence of a reasonably high percentage of α-linolenic acid, or to a combination of properties of fresh unrefined oil, is as yet uncertain. Care needs to be taken with such epidemiological studies to exclude the possibility of early deaths from other causes skewing the results. The fact that early asymptomatic coronary disease is readily detectable post mortem and is absent in the mustard oil cohorts tends to add weight to the hypothesis that mustard oil is protective.<ref>{{cite journal |author=Rastogi T, Reddy KS, Vaz M, ''et al.'' |title=Diet and risk of ischemic heart disease in India |journal=Am. J. Clin. Nutr. |volume=79 |issue=4 |pages=582–92 |year=2004 |month=April |pmid=15051601 |doi= |url=http://www.ajcn.org/cgi/content/full/79/4/582 }}</ref> | Epidemiological studies suggest that, in regions where mustard oil is still used in a traditional manner, mustard oil may afford some protection against cardiovascular diseases. In this sense 'traditional' means that (a) the oil is used fresh and (b) vegetable fats count only as a small percentage of the total caloric intake. Whether this effect is due to the nature of erucic acid ''per se'' to make the blood platelets less sticky, or to the presence of a reasonably high percentage of α-linolenic acid, or to a combination of properties of fresh unrefined oil, is as yet uncertain. Care needs to be taken with such epidemiological studies to exclude the possibility of early deaths from other causes skewing the results. The fact that early asymptomatic coronary disease is readily detectable post mortem and is absent in the mustard oil cohorts tends to add weight to the hypothesis that mustard oil is protective.<ref>{{cite journal |author=Rastogi T, Reddy KS, Vaz M, ''et al.'' |title=Diet and risk of ischemic heart disease in India |journal=Am. J. Clin. Nutr. |volume=79 |issue=4 |pages=582–92 |year=2004 |month=April |pmid=15051601 |doi= |url=http://www.ajcn.org/cgi/content/full/79/4/582 }}</ref> | ||
Revision as of 01:10, 24 January 2012
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| Names | |
|---|---|
| IUPAC name (Z)-Docos-13-enoic acid | |
| Identifiers | |
| CAS Number | |
| 3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.003.647 
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| KEGG | |
| PubChem CID | |
| UNII | |
| CompTox Dashboard (EPA) | |
InChI
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SMILES
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| Properties | |
| Chemical formula | C22H42O2 |
| Molar mass | 338.576 g·mol |
| Appearance | White waxy solid |
| Density | 0.860 g/cm |
| Melting point | 33.8 °C (92.8 °F; 306.9 K) |
| Boiling point | 381.5 °C (decomposes) |
| Solubility in water | Insoluble |
| Solubility in methanol and ethanol | Soluble |
| Hazards | |
| Flash point | 349.9 °C (661.8 °F) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).
 Y verify (what is ?)
Infobox references
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Erucic acid is a monounsaturated omega-9 fatty acid, denoted 22:1 ω-9. It has the formula CH3(CH2)7CH=CH(CH2)11COOH. It is prevalent in rapeseed, wallflower seed, and mustard seed, making up 4.1% of their oils. Erucic acid is also known as cis-13-docosenoic acid and the trans isomer is known as brassidic acid.
Uses
Erucic acid has many of the same uses as mineral oils, but it is more readily biodegradable than some. It has limited ability to polymerize and dry for use in oil paints. Like other fatty acids, it can be converted into surfactants, lubricant and is a precursor to bio-diesel.
Derivatives of erucic acid have many further uses, such as behenyl alcohol (CH3(CH2)21OH), a pour point depressant (enabling liquids to flow at a lower temperature), and silver behenate, for use in photography. It is also used as an ingredient in appetite suppressants.
Sources of erucic acid
The name erucic means: of or pertaining to eruca; which is a genus of flowering plants in the family Brassicaceae. It is also the Latin for coleworth, which today is better known as kale.
Erucic acid is produced naturally (together with other fatty acids) across a great range of green plants, but especially so in members of the brassica family. It is highest in some of the rapeseed varieties of brassicas, kale and mustard being some of the highest, followed by Brussels spouts and broccoli. For industrial purposes, a Low-Erucic Acid Rapeseed (LEAR) has been developed, which contains fats derived from oleic acid instead of erucic acid.
Biochemistry
Further information: ]Erucic acid is produced by elongation of oleic acid via oleoyl-coenzyme A and malonyl-CoA. Erucic acid is broken down into shorter-chain fatty acids in the human liver by the long-chain Acyl CoA dehydrogenase enzyme.
Health effects
Epidemiological studies suggest that, in regions where mustard oil is still used in a traditional manner, mustard oil may afford some protection against cardiovascular diseases. In this sense 'traditional' means that (a) the oil is used fresh and (b) vegetable fats count only as a small percentage of the total caloric intake. Whether this effect is due to the nature of erucic acid per se to make the blood platelets less sticky, or to the presence of a reasonably high percentage of α-linolenic acid, or to a combination of properties of fresh unrefined oil, is as yet uncertain. Care needs to be taken with such epidemiological studies to exclude the possibility of early deaths from other causes skewing the results. The fact that early asymptomatic coronary disease is readily detectable post mortem and is absent in the mustard oil cohorts tends to add weight to the hypothesis that mustard oil is protective.
A four-to-one mixture of erucic acid and oleic acid constitutes Lorenzo's oil; an experimental treatment for a rare neurobiology disorder adrenoleukodystrophy. Thrombocytopenia has been seen in patients treated with Lorenzo's oil, probably related to its erucic acid content. For the reasons given above, it is not advisable for nursing mothers or babies to eat food containing erucic acid.
The high percentage of erucic acid in mustard oil has led to the latter being banned for food use in the European Union and other countries.
Health concerns
Before genetic engineering, plant breeders were aiming to produce a less-bitter-tasting multi-purpose oil from rapeseed that would appeal to a larger market by making it more palatable for cattle and other livestock. While it was possible to breed out much of the pungent-tasting glucosinolates, one of the dominant erucic acid genes would get stripped out of the genome as well, greatly reducing its valuable erucic acid content. Studies on rats show lipodosis problems when fed high quantities of erucic acid, however, so this did not hinder saleability. Later trials showed that rats had the same problems with other vegetable fatty acids, because rats are poor at metabolising some fats. The plant breeding industry later changed "low erucic acid" to be its unique selling proposition over that of its competitors.
There are not many studies done on humans with erucic acid; the majority are carried out by the food science industry on animals. Animal studies failed to show negative events occurring from feeding of erucic acid, and the studies were repeated under increasingly unnatural scenarios. In one case, neonate piglets that have a limited ability to absorb these fats had their normal sow's milk replaced solely with rapeseed oil for one hundred percent of their calorific needs. The studies showed that lipidoses suffered by the piglets proved to be only a transient effect; the liver automatically responded by increasing enzyme levels to cope with the unusual diet, and the lipidoses subsided.
A recent study recorded the higher rates of lung cancer in countries with populations that cook over solid fuel wood and biomass fires and stoves. The possibility of production of smoke from heated oil was also considered, and it was established that rapeseed oil, which contains erucic acid, can cause increased lung carcinomas through emissions under high heat. However, the report also showed a variety of cooking oils also did this at similar heats.
Cardiac concerns
The levels of erucic acid in human foods are restricted, in part, over concerns that it may adversely affect heart tissue. However, these concerns seem to have been premature: an early study had shown rapeseed oil, which contains erucic acid, promoted myocardial lesions in male adult rat animal models; but later studies revealed similar effects from other oils, containing no erucic acid ; also, the same effects were not observed in female adult rats. Choline and inositol offered some protection against this damage, while alpha-linolenic acid may have aggravated it. Erucic acid is preferentially absorbed in myocardium tissue but is not metabolized there.
As the above, these studies demonstrate, rats present a poor animal model to study the effects of erucic acid on human heart tissue due to their own poor ability to metabolize this fat.
Low erucic acid rapeseed
Before the advent of genetic engineering, plant breeders were aiming to produce a less-bitter-tasting multi-purpose crop from oil-rapeseed that would appeal to a larger market by making it more palatable and safer for cattle and other livestock. While it was possible to breed out much of the pungent-tasting glucosinolates that were the cause of the problem, the traditional methods of plant breeding resulted in one of the dominant erucic acid genes also getting stripped out of the genome in the process, thus greatly reducing its erucic acid content. Although this latter effect was an unintended consequence of the breeding program, it was noticed from studies on rats that they show signs of lipidosis when fed high quantities of erucic acid.
Food grade rapeseed oil (also known as canola oil, rapeseed 00 oil, low erucic acid rapeseed oil, LEAR oil, and rapeseed canola-equivalent oil) is regulated to a maximum of 2% erucic acid by weight in the USA. and 5% in the EU, with special regulations for infant food.
References
- Sahasrabudhe, M. R. (1977). "Crismer values and erucic acid contents of rapeseed oils". Journal of the American Oil Chemists' Society. 54 (8): 323–324. doi:10.1007/BF02672436.
- Economic Research Service, USDA (1996). "Crambe, Industrial Rapeseed, and Tung Provide Valuable Oils" (pdf). Fats and Oils, Industrial Uses: 18.
- ^ Xiaoming Bao, Mike Pollard, and John Ohlrogge"The Biosynthesis of Erucic Acid in Developing Embryos of Brassica rapa" Plant Physiol. 1998, vol 118, pp.183–190. PMID 9733537
- David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a10_245.pub2
- Rastogi T, Reddy KS, Vaz M; et al. (2004). "Diet and risk of ischemic heart disease in India". Am. J. Clin. Nutr. 79 (4): 582–92. PMID 15051601.
{{cite journal}}: Explicit use of et al. in:|author=(help); Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - Crowther MA, Barr RD, Kelton J, Whelan D, Greenwald M (1995). "Profound thrombocytopenia complicating dietary erucic acid therapy for adrenoleukodystrophy". American Journal of Hematology. 48 (2): 132–3. PMID 7847331.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Food Standards Australia New Zealand (June 2003) Erucic acid in food : A Toxicological Review and Risk Assessment . Technical report series No. 21; Page 4 paragraph 1; ISBN 0 642 34526 0, ISSN 1448-3017
- "Food Standards Agency - Agency issues warning on erucic acid". 2 September 2004. Retrieved 2 November 2007.
- ^ Charlton KM, Corner AH, Davey K, Kramer JK, Mahadevan S, Sauer FD (1975). "Cardiac lesions in rats fed rapeseed oils". Can. J. Comp. Med. 39 (3): 261–9. PMC 1277456. PMID 1170010.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - Neat CE, Thomassen MS, Osmundsen H (1981). "Effects of high-fat diets on hepatic fatty acid oxidation in the rat. Isolation of rat liver peroxisomes by vertical-rotor centrifugation by using a self-generated, iso-osmotic, Percoll gradient". Biochem. J. 196 (1): 149–59. PMC 1162977. PMID 6272750.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Kramer JK, Hulan HW, Trenholm HL, Corner AH (1979). "Growth, lipid metabolism and pathology of two strains of rats fed high fat diets". J. Nutr. 109 (2): 202–13. PMID 430222.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) Cite error: The named reference "Kramer" was defined multiple times with different content (see the help page). - S Kurt, Baan R, Grosse Y, Secretan B, (2006) Carcinogenicity of household solid fuel combustion and of high-temperature frying. WHO International Agency for Research on Cancer Monograph Working Group. PDF 52kb. Retrieved 2007-01-29
- ^ Clandinin MT, Yamashiro S (1982). "Dietary factors affecting the incidence of dietary fat-induced myocardial lesions". J. Nutr. 112 (4): 825–8. PMID 7200131.
{{cite journal}}:|access-date=requires|url=(help) - McCutcheon JS, Umermura T, Bhatnager MK, Walker BL (1976). "Cardiopathogenicity of rapeseed oils and oil blends differing in erucic, linoleic, and linolenic acid content". Lipids. 11 (7): 545–52. doi:10.1007/BF02532900. PMID 948250.
{{cite journal}}:|access-date=requires|url=(help)CS1 maint: multiple names: authors list (link) - Becker W, Bruce A (1985). "Autoradiographic studies with fatty acids and some other lipids: a review". Prog. Lipid Res. 24 (4): 325–46. doi:10.1016/0163-7827(85)90010-4. PMID 3916594.
{{cite journal}}:|access-date=requires|url=(help) - U.S. Dept. of Health and Human Services (1 April 2010). "CFR - Code of Federal Regulations Title 21".
- The Commission of the European Communities (27 September 1980). "Commission Directive 80/891/EEC of 25 July 1980 relating to the Community method of analysis for determining the erucic acid content in oils and fats intended to be used as such for human consumption and foodstuffs containing added oils or fats". EurLex Official Journal. 254: 35–41.
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