Monounsaturated fat 1051404 224750884 2008-07-10T07:19:52Z 72.194.121.107 /* Natural sources */ {{Expand|date=January 2007}} {{Fats}} :''For discussion how dietary fats affect cardiovascular health, see [[Diet and heart disease]].'' In [[biochemistry]] and nutrition, '''''monounsaturated fats''''' are [[fatty acids]] that have a single [[double bond]] in the fatty acid chain and all the [[carbon]] [[atom]]s in the chain are [[single bond|single-bonded]]. By contrast, [[polyunsaturated]] fatty acids have more than one double bond. [[Fatty acid]]s are long-chained [[molecule]]s having a [[methyl]] group at one end and a [[carboxylic acid]] group at the other end. Fatty acid [[fluidity]] increases with increasing number of double bonds. Therefore, monounsaturated fatty acids have a higher [[melting temperature]] than polyunsaturated fatty acids but lower than [[saturated fat|saturated]] fatty acids. Monounsaturated fatty acids are liquids at room temperature and semisolid or solid when refrigerated. == Molecular description: oleic acid == Common monounsaturated fatty acids are [[palmitoleic acid]] (16:1&nbsp;n&minus;7), cis-vaccenic acid (18:1&nbsp;n&minus;7) and [[oleic acid]] (18:1&nbsp;n&minus;9). Palmitoleic acid has 16 carbon atoms with the first double bond occurring 7 carbon atoms away from the methyl group (and 9 carbons from the carboxyl end). It can be lengthened to the 18-carbon cis-vaccenic acid. Oleic acid has 18 carbon atoms with the first double bond occurring 9 carbon atoms away from the methyl group. The illustrations below show a molecule of oleic acid in Lewis formula and as a [[space-filling model]]. <center>[[Image:Oleic-acid-skeletal.svg|300px|Oleic acid's skeletal formula]] [[Image:Oleic-acid-3D-vdW.png|250px|Oleic acid's space-filling structure]]</center> == Relation to health == Although polyunsaturated fats protect against cardiovascular disease by providing more [[biological membrane|membrane]] fluidity than monounsaturated fats, they are more vulnerable to [[lipid peroxidation]] ([[rancidification|rancidity]]). On the other hand, some monounsaturated fatty acids (like saturated fats) promote [[insulin resistance]], whereas polyunsaturated fatty acids are protective against insulin resistance <ref>{{cite journal| author=Lovejoy, JC| title=The influence of dietary fat on insulin resistance| journal=Current Diabetes Reports| year=2002| volume=2| issue=5| pages= 435&ndash;440| pmid=12643169| doi=10.1007/s11892-002-0098-y}}</ref><ref>{{cite journal| author=Satoshi Fukuchi| title=Role of Fatty Acid Composition in the Development of Metabolic Disorders in Sucrose-Induced Obese Rats| journal=Experimental Biology and Medicine| year=2004| volume=229| issue=6| pages= 486&ndash;493| url=http://www.ebmonline.org/cgi/content/full/229/6/486| pmid=15169967}}</ref>. In direct contrast to this, the large scale KANWU study found that neither dietary monounsaturated or supplemented polyunsaturated fats (in the form of fish oil) affected insulin sensitivity, while increased consumption of saturated fat induced a significant decrease in this parameter. <ref>{{cite journal| author=Vessby B, Unsitupa M, Hermansen K, Riccardi G, Rivellese AA, Tapsell LC, Nälsén C, Berglund L, Louheranta A, Rasmussen BM, Calvert GD, Maffetone A, Pedersen E, Gustafsson IB, Storlien LH| title=Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study| journal=Diabetologia| year=2001| volume=44| issue=3| pages= 312&ndash;319| url=http://www.ncbi.nlm.nih.gov/pubmed/11317662?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=2| pmid=11317662| doi=10.1007/s001250051620}}</ref> Foods containing monounsaturated fats lower [[LDL]] cholesterol, while possibly raising [[High density lipoprotein|HDL]] cholesterol.<ref>''You Can Control Your Cholesterol: A Guide to Low-Cholesterol Living'' by [[Merck & Co.]] Inc.</ref> However, their true ability to raise HDL is still in debate. Olive oil is a key component of Mediterranean cuisine, widely regarded as being protective against [[cardiovascular disease]], while [[tea oil]] is a traditional part of Asian cuisine. In a study published in 2001, [[erythrocyte membrane]] oleic and monounsaturated fatty acid content was positively associated with [[breast cancer]] risk in postmenopausal women, while no association was shown between saturated fatty acids and breast cancer risk. Enzyme Δ9-desaturase catalyzes the conversion of stearic acid to oleic acid: there is a negative correlation between [[erythrocyte membrane]] oleic acid and dietary [[polyunsaturated fatty acid]]s. Inverse relationship between Saturation Index (ratio of membrane stearic to oleic acid) and breast cancer risk could also be related to hormonal and metabolic factors and to interactions between them, as well as to dietary factors.<ref>{{cite journal |author=Valeria Pala, Vittorio Krogh, Paola Muti, Véronique Chajès, Elio Riboli, Andrea Micheli, Mitra Saadatian, Sabina Sieri, Franco Berrino |title=Erythrocyte Membrane Fatty Acids and Subsequent Breast Cancer: a Prospective Italian Study |journal=JNCL |volume=93 |year=2001 |url=http://jnci.oxfordjournals.org/cgi/content/full/93/14/1088 |accessdate=2008-03-22 |pmid=11459870}}</ref> In children, consumption of monounsaturated oils is associated with healthier serum lipid profiles.<ref name=pmid_17333272>{{cite journal |author=Sanchez-Bayle M, Gonzalez-Requejo A, Pelaez MJ, Morales MT, Asensio-Anton J, Anton-Pacheco E |title=A cross-sectional study of dietary habits and lipid profiles. The Rivas-Vaciamadrid study |journal=Eur. J. Pediatr. |volume=167 |issue=2 |pages=149–54 |year=2008 |pmid=17333272 |doi=10.1007/s00431-007-0439-6}}</ref> == Natural sources == Monounsaturated fats are found in natural foods such as [[Nut (fruit)|nuts]] and [[avocado]]s, and are the main component of [[tea seed oil]] and [[olive oil]] ([[oleic acid]]). [[Canola oil]] is 57%–60% monounsaturated fat, olive oil is about 75% monounsaturated fat while [[tea seed oil]] is commonly over 80% monounsaturated fat. Other sources include [[Grape seed oil|grapeseed oil]], [[ground nut]] oil, [[peanut oil]], [[flaxseed oil]], [[sesame oil]], [[corn oil]], [[popcorn]], [[whole grain]] [[wheat]], [[cereal]], [[oatmeal]], [[safflower oil]], [[sunflower oil]], [[tea-oil Camellia]], [[avocado oil]]. == References == <references/> Mustard seed oil too a very good source of mono unsaturated fat. Its is widely used in North India in their food. ==See also== * [[High density lipoprotein]] * [[Saturated fat]] * [[Unsaturated fat]] ** [[Polyunsaturated|Polyunsaturated fat]] ==External links== * [http://www.mayoclinic.com/health/diabetes-diet/DA00075 Fats (Mayo Clinic)] * [http://www.heartmaine.com/resources/types-of-fats.php Types of Fats (Cardiovascular Consultants)] Some "dated" information. * [http://www.benbest.com/health/essfat.html#chem The Chemistry of Unsaturated Fats] [[Category:Food science]] [[Category:Fatty acids|#]] [[Category:Lipids]] [[Category:Nutrition]] [[no:Enumettet fett]] [[simple:Monounsaturated fat]] [[fi:Kertatyydyttymätön rasvahappo]] [[pt:Gordura monoinsaturada]] [[zh:單元不飽和脂肪]]