title: Low-n-6 and low-n-6 plus high-n-3 diets for use in clinical research.
abstract: Few trials have evaluated the metabolic effects and health outcomes of lowering dietary n-6 PUFA. The objectives of the present paper were (1) to report the methods employed to lower dietary n-6 PUFA, while either increasing or maintaining n-3 PUFA intake and (2) to validate our methods with 24 h recalls and erythrocyte fatty acid analyses. A total of sixty-seven subjects were randomised to either (1) an average-n-3 PUFA, low-n-6 PUFA (L6) intervention designed to lower linoleic acid (LA; #2·5% of energy (en%)) and arachidonic acid (#60 mg/d), while maintaining an average US intake of n-3 PUFA or (2) a high-n-3 PUFA, low-n-6 PUFA (H3-L6) intervention designed to lower n-6 LA, while increasing the n-3 PUFA a-linolenic acid (ALA; $1·5 en%) and EPA þ DHA ($1000 mg/d). Pre- and intraintervention nutrient intakes were estimated with six 24 h dietary recalls per subject. Both groups achieved the targeted reductions in dietary LA to #2·5 en% (median LA 2·45 (2·1, 3·1); P,0·001). Intakes of n-3 PUFA did not change for the L6 group. Target increases in n-3 ALA (median 1·6 en%, (1·3, 2·0), P,0·001) and EPA þ DHA (1482 mg, (374, 2558), P,0·001) were achieved in the H3-L6 group. Dietary changes were validated by corresponding changes in erythrocyte n-6 and n-3 fatty acid composition. Dietary LA can be lowered to #2·5 en%, with or without concurrent increases in dietary n-3 PUFA, in an outpatient clinical trial setting using this integrated diet method.
authors: Nutrition Research and Metabolism Core, North Carolina Translational Clinical Sciences Institute, 101 Manning Drive, CB#7600, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. beth_macintosh@med.unc.edu
authors: Beth A
authors: BA
authors: MacIntosh
authors: Christopher E
authors: CE
authors: Ramsden
authors: Keturah R
authors: KR
authors: Faurot
authors: Daisy
authors: D
authors: Zamora
authors: Margaret
authors: M
authors: Mangan
authors: Joseph R
authors: JR
authors: Hibbeln
authors: J Douglas
authors: JD
authors: Mann
mesh_terms: D000293:Adolescent; D000328:Adult; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000097:blood; D035843:Biomedical Research / Q000379:methods; D004041:Dietary Fats / Q000008:administration & dosage* / Q000097:blood; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000097:blood; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000097:blood; D002149:Energy Intake; D004912:Erythrocytes / Q000737:chemistry; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage* / Q000097:blood; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D019787:Linoleic Acid / Q000008:administration & dosage* / Q000097:blood; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015596:Nutrition Assessment; D014481:United States; D055815:Young Adult; D017962:alpha-Linolenic Acid / Q000008:administration & dosage / Q000097:blood
chemical_list: D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid