| 词条 | Monounsaturated fat | |||||||||||||||||||||||||||||||||||||||||||||
| 释义 |
In biochemistry and nutrition, monounsaturated fatty acids (abbreviated MUFAs, or more plainly monounsaturated fats) are fatty acids that have one double bond in the fatty acid chain with all of the remainder carbon atoms being single-bonded. By contrast, polyunsaturated fatty acids (PUFAs) have more than one double bond. Molecular descriptionFatty acids are long-chained molecules having an alkyl group at one end and a carboxylic acid group at the other end. Fatty acid viscosity (thickness) and melting temperature increases with decreasing number of double bonds; therefore, monounsaturated fatty acids have a higher melting point than polyunsaturated fatty acids (more double bonds) and a lower melting point than saturated fatty acids (no double bonds). Monounsaturated fatty acids are liquids at room temperature and semisolid or solid when refrigerated resulting in a isotopic lattice structure. Common monounsaturated fatty acids are palmitoleic acid (16:1 n−7), cis-vaccenic acid (18:1 n−7) and oleic acid (18:1 n−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 carboxylic acid group. The illustrations below show a molecule of oleic acid in Lewis formula and as a space-filling model. List of monounsaturated fats
HealthMonounsaturated fats protect against cardiovascular disease by providing more membrane fluidity than saturated fats{{Citation needed|date=March 2019}}, but they are more vulnerable to lipid peroxidation (rancidity). The large scale KANWU study found that increasing monounsaturated fat and decreasing saturated fat intake could improve insulin sensitivity, but only when the overall fat intake of the diet was low.[1] However, some monounsaturated fatty acids (in the same way as saturated fats) may promote insulin resistance, whereas polyunsaturated fatty acids may be protective against insulin resistance.[2][3] Studies have shown that substituting dietary monounsaturated fat for saturated fat is associated with increased daily physical activity and resting energy expenditure. More physical activity was associated with a higher-oleic acid diet than one of a palmitic acid diet. From the study, it is shown that more monounsaturated fats lead to less anger and irritability.[4] Foods containing monounsaturated fats reduce low-density lipoprotein (LDL) cholesterol,[5] while possibly increasing high-density lipoprotein (HDL) cholesterol.[6] Levels of oleic acid along with other monounsaturated fatty acids in red blood cell membranes were positively associated with breast cancer risk. The saturation index (SI) of the same membranes was inversely associated with breast cancer risk. Monounsaturated fats and low SI in erythrocyte membranes are predictors of postmenopausal breast cancer. Both of these variables depend on the activity of the enzyme delta-9 desaturase (Δ9-d).[7] In children, consumption of monounsaturated oils is associated with healthier serum lipid profiles.[8] The Mediterranean diet is one heavily influenced by monounsaturated fats. People in Mediterranean countries consume more total fat than Northern European countries, but most of the fat is in the form of monounsaturated fatty acids from olive oil and omega-3 fatty acids from fish, vegetables, and certain meats like lamb, while consumption of saturated fat is minimal in comparison. A 2017 review found evidence that the practice of a Mediterranean diet could lead to a decreased risk of cardiovascular diseases, overall cancer incidence, neurodegenerative diseases, diabetes, and early death.[9] A 2018 review showed that the practice of the Mediterranean diet may improve overall health status, such as reduced risk of non-communicable diseases, reduced total costs of living, and reduced costs for national healthcare.[10] SourcesMonounsaturated fats are found in animal flesh such as red meat, whole milk products, nuts, and high fat fruits such as olives and avocados. Olive oil is about 75% monounsaturated fat.[11] The high oleic variety sunflower oil contains as much as 85% monounsaturated fat.{{Citation needed|date=August 2015}} Canola oil and cashews are both about 58% monounsaturated fat.{{Citation needed|date=August 2015}} Tallow (beef fat) is about 50% monounsaturated fat.[12] and lard is about 40% monounsaturated fat.{{Citation needed|date=August 2015}} Other sources include avocado oil, macadamia nut oil, grapeseed oil, groundnut oil (peanut oil), sesame oil, corn oil, popcorn, whole grain wheat, cereal, oatmeal, almond oil, sunflower oil, hemp oil, and tea-oil Camellia.[13] {{Fat composition in different foods}}See also
References1. ^{{cite journal | vauthors = Vessby B, Uusitupa 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 | volume = 44 | issue = 3 | pages = 312–9 | date = March 2001 | pmid = 11317662 | doi = 10.1007/s001250051620 }} 2. ^{{cite journal | vauthors = Lovejoy JC | title = The influence of dietary fat on insulin resistance | journal = Current Diabetes Reports | volume = 2 | issue = 5 | pages = 435–40 | date = October 2002 | pmid = 12643169 | doi = 10.1007/s11892-002-0098-y }} 3. ^{{cite journal | vauthors = Fukuchi S, Hamaguchi K, Seike M, Himeno K, Sakata T, Yoshimatsu H | title = Role of fatty acid composition in the development of metabolic disorders in sucrose-induced obese rats | journal = Experimental Biology and Medicine | volume = 229 | issue = 6 | pages = 486–93 | date = June 2004 | pmid = 15169967 | doi = 10.1177/153537020422900606 }} 4. ^{{cite journal | vauthors = Kien CL, Bunn JY, Tompkins CL, Dumas JA, Crain KI, Ebenstein DB, Koves TR, Muoio DM | title = Substituting dietary monounsaturated fat for saturated fat is associated with increased daily physical activity and resting energy expenditure and with changes in mood | journal = The American Journal of Clinical Nutrition | volume = 97 | issue = 4 | pages = 689–97 | date = April 2013 | pmid = 23446891 | pmc = 3607650 | doi = 10.3945/ajcn.112.051730 }} 5. ^{{cite web |title = You Can Control Your Cholesterol: A Guide to Low-Cholesterol Living |publisher = MerckSource |url = http://www.mercksource.com/pp/us/cns/cns_krames_template.jspzQzpgzEzzSzppdocszSzuszSzcnszSzcontentzSzkrameszSz1292_01zPzhtm |access-date = 2018-01-02 |archive-url = https://web.archive.org/web/20090303124418/http://www.mercksource.com/pp/us/cns/cns_krames_template.jspzQzpgzEzzSzppdocszSzuszSzcnszSzcontentzSzkrameszSz1292_12zPzhtm |archive-date = 2009-03-03 |deadurl = yes |df = }} 6. ^{{cite web |title = Monounsaturated Fat |publisher = American Heart Association |url = https://healthyforgood.heart.org/Eat-smart/Articles/Monounsaturated-Fats |access-date = 2018-04-19 |archive-url = https://web.archive.org/web/20180307184535/https://healthyforgood.heart.org/Eat-smart/Articles/Monounsaturated-Fats |archive-date = 2018-03-07 |deadurl = no |df = }} 7. ^{{cite journal | vauthors = Pala V, Krogh V, Muti P, Chajès V, Riboli E, Micheli A, Saadatian M, Sieri S, Berrino F | title = Erythrocyte membrane fatty acids and subsequent breast cancer: a prospective Italian study | journal = Journal of the National Cancer Institute | volume = 93 | issue = 14 | pages = 1088–95 | date = July 2001 | pmid = 11459870 | doi = 10.1093/jnci/93.14.1088 }} 8. ^{{cite journal | vauthors = 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 = European Journal of Pediatrics | volume = 167 | issue = 2 | pages = 149–54 | date = February 2008 | pmid = 17333272 | doi = 10.1007/s00431-007-0439-6 }} 9. ^{{cite journal | vauthors = Dinu M, Pagliai G, Casini A, Sofi F | title = Mediterranean diet and multiple health outcomes: an umbrella review of meta-analyses of observational studies and randomised trials | journal = European Journal of Clinical Nutrition | volume = 72 | issue = 1 | pages = 30–43 | date = January 2018 | pmid = 28488692 | doi = 10.1038/ejcn.2017.58 }} 10. ^{{cite journal | vauthors = Martinez-Lacoba R, Pardo-Garcia I, Amo-Saus E, Escribano-Sotos F | title = Mediterranean diet and health outcomes: a systematic meta-review | journal = European Journal of Public Health | volume = 28 | issue = 5 | pages = 955–961 | date = October 2018 | pmid = 29992229 | doi = 10.1093/eurpub/cky113 }} 11. ^{{cite journal | vauthors = Abdullah MM, Jew S, Jones PJ | title = Health benefits and evaluation of healthcare cost savings if oils rich in monounsaturated fatty acids were substituted for conventional dietary oils in the United States | journal = Nutrition Reviews | volume = | issue = | pages = | date = February 2017 | pmid = 28158733 | pmc = 5914363 | doi = 10.1093/nutrit/nuw062 }} 12. ^{{cite book | author = Board on Agriculture and Renewable Resources Commission on Natural Resources and Food and Nutrition Board, Assembly of Life Sciences, National Research Council|title=Fat content and composition of animal products: proceedings of a symposium, Washington, D.C., December 12-13, 1974 | date = 1976 | publisher = National Academy of Sciences|location=Washington|isbn=978-0-309-02440-2 | url = https://www.ncbi.nlm.nih.gov/books/NBK216535/ | pmid = 25032409}} 13. ^{{cite journal | vauthors = Aizpurua-Olaizola O, Ormazabal M, Vallejo A, Olivares M, Navarro P, Etxebarria N, Usobiaga A | title = Optimization of supercritical fluid consecutive extractions of fatty acids and polyphenols from Vitis vinifera grape wastes | journal = Journal of Food Science | volume = 80 | issue = 1 | pages = E101-7 | date = January 2015 | pmid = 25471637 | doi = 10.1111/1750-3841.12715 }} External links
4 : Food science|Fatty acids|Lipids|Nutrition |
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