1. Low-n-6 and low-n-6 plus high-n-3 diets for use in clinical research.
- Author
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MacIntosh BA, Ramsden CE, Faurot KR, Zamora D, Mangan M, Hibbeln JR, and Mann JD
- Subjects
- Adolescent, Adult, Arachidonic Acid administration & dosage, Arachidonic Acid blood, Biomedical Research methods, Dietary Fats blood, Docosahexaenoic Acids administration & dosage, Docosahexaenoic Acids blood, Eicosapentaenoic Acid administration & dosage, Eicosapentaenoic Acid blood, Erythrocytes chemistry, Fatty Acids, Omega-3 blood, Female, Humans, Linoleic Acid blood, Male, Mental Recall, Middle Aged, United States, Young Adult, alpha-Linolenic Acid administration & dosage, alpha-Linolenic Acid blood, Dietary Fats administration & dosage, Energy Intake, Fatty Acids, Omega-3 administration & dosage, Feeding Behavior, Linoleic Acid administration & dosage, Nutrition Assessment
- 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.
- Published
- 2013
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