title: Total dietary fat and fatty acid content modifies plasma phospholipid fatty acids, desaturase activity indices, and urinary prostaglandin E in women.
abstract: Compared with diets high in fat, low-fat diets are associated with reduced risk of cardiovascular disease. We hypothesized that a low-fat (LF) (20% fat) and an LF high-omega-3 (n-3) fatty acid diet (LFn3) (23% fat with 3% as α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid [DHA]) would enhance n-3 composition of plasma phospholipid fatty acid and reduce urinary prostaglandin E(2) (PGE(2)) relative to a high-fat diet (HF) (40% fat) and that these changes would be associated with alterations in δ5 desaturase (D5D) and δ6 desaturase (D6D) activity. Phospholipid fatty acids and urinary PGE(2) were measured, and D5D and D6D activity indices calculated in a crossover trial in 17 postmenopausal women fed each of 3 test diets (HF, LF, and LFn3) for 8-week feeding periods. Desaturase activity indices were calculated as D5D, 20:4n-6/20:3n-6, and D6D, 20:3n-6/18:2n-6. Plasma phospholipid fatty acid, α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid (DPA), DHA, and total n-3 fatty acids increased, whereas linoleic acid and arachidonic acid decreased with consumption of LFn3. The LF resulted in enhanced arachidonic acid and DHA. High fat reduced D6D, whereas both HF and LF increased D5D. Urinary PGE(2) was reduced in response to both the LF and LFn3 diets. Low-fat diets, with or without long-chain n-3 fatty acids, promote positive health effects due in part to favorable alteration of plasma phospholipid fatty acid profiles and modification in desaturase activity indices, suggesting that the type and amount of fat consumed are modifiable risk factors for the prevention of cardiovascular disease.
authors.affiliation: ARS, USDA, Human Nutrition Research Center, Grand Forks, ND 58203, USA. susan.raatz@ars.usda.gov
authors.forename: Susan K
authors.initials: SK
authors.lastname: Raatz
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Young
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Picklo
authors.forename: Edward R
authors.initials: ER
authors.lastname: Sauter
authors.forename: Wenyi
authors.initials: W
authors.lastname: Qin
authors.forename: Mindy S
authors.initials: MS
authors.lastname: Kurzer
mesh_terms: D000368:Aged; D016718:Arachidonic Acid / Q000097:blood; D018592:Cross-Over Studies; D000090943:Delta-5 Fatty Acid Desaturase; D018752:Diet, Fat-Restricted; D059305:Diet, High-Fat; D015118:Eicosapentaenoic Acid / Q000097:blood*; D044943:Fatty Acid Desaturases / Q000097:blood*; D005231:Fatty Acids, Unsaturated / Q000097:blood*; D005260:Female; D006801:Humans; D019787:Linoleic Acid / Q000097:blood; D050602:Linoleoyl-CoA Desaturase / Q000097:blood*; D008875:Middle Aged; D010743:Phospholipids / Q000097:blood; D017698:Postmenopause; D011458:Prostaglandins E / Q000652:urine*; D012307:Risk Factors; D017962:alpha-Linolenic Acid / Q000097:blood*
chemical_list: D000090943:Delta-5 Fatty Acid Desaturase; D005231:Fatty Acids, Unsaturated; D010743:Phospholipids; D011458:Prostaglandins E; D017962:alpha-Linolenic Acid; D016718:Arachidonic Acid; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase; C026219:docosapentaenoic acid