title: Levels of bioactive lipids in cooking oils: olive oil is the richest source of oleoyl serine.
abstract: BACKGROUND
  Rates of osteoporosis are significantly lower in regions of the world where olive oil consumption is a dietary cornerstone. Olive oil may represent a source of oleoyl serine (OS), which showed efficacy in animal models of osteoporosis. Here, we tested the hypothesis that OS as well as structurally analogous N-acyl amide and 2-acyl glycerol lipids are present in the following cooking oils: olive, walnut, canola, high heat canola, peanut, safflower, sesame, toasted sesame, grape seed, and smart balance omega.
  
  
  METHODS
  Methanolic lipid extracts from each of the cooking oils were partially purified on C-18 solid-phase extraction columns. Extracts were analyzed with high-performance liquid chromatography-tandem mass spectrometry, and 33 lipids were measured in each sample, including OS and bioactive analogs.
  
  
  RESULTS
  Of the oils screened here, walnut oil had the highest number of lipids detected (22/33). Olive oil had the second highest number of lipids detected (20/33), whereas grape-seed and high-heat canola oil were tied for lowest number of detected lipids (6/33). OS was detected in 8 of the 10 oils tested and the levels were highest in olive oil, suggesting that there is something about the olive plant that enriches this lipid.
  
  
  CONCLUSIONS
  Cooking oils contain varying levels of bioactive lipids from the N-acyl amide and 2-acyl glycerol families. Olive oil is a dietary source of OS, which may contribute to lowered prevalence of osteoporosis in countries with high consumption of this oil.
authors.forename: Heather B
authors.initials: HB
authors.lastname: Bradshaw
authors.forename: Emma
authors.initials: E
authors.lastname: Leishman
mesh_terms: D000818:Animals; D003296:Cooking; D004032:Diet; D008055:Lipids / Q000737:chemistry*; D000069463:Olive Oil / Q000032:analysis* / Q000737:chemistry*; D010024:Osteoporosis / Q000517:prevention & control; D010938:Plant Oils / Q000032:analysis* / Q000737:chemistry*; D000074262:Rapeseed Oil; D051381:Rats; D017208:Rats, Wistar; D012694:Serine / Q000737:chemistry*
chemical_list: D008055:Lipids; D000069463:Olive Oil; D010938:Plant Oils; D000074262:Rapeseed Oil; D012694:Serine