The effects of dietary n-3/n-6 ratio on brain development in the mouse: a dose response study with long-chain n-3 fatty acids.
This study examines the effects of the ratio of n-3/n-6 fatty acids (FA) on brain development in mice when long-chain n-3 FA are supplied in the diet. From conception until 12 days after birth, B6D2F1 mice were fed liquid diets, each providing 10% of energy from olive oil, and a further 10% from different combinations of free FA concentrates derived from safflower oil (18:2n-6), and fish oil (20:5n-3 and 22:6n-3). The range of dietary n-3/n-6 ratios was 0, 0.25, 0.5, 1.0, 2.0 and 4.0, with an n-6 content of greater than 1.5% of energy in all diets, and similar levels of total polyunsaturated fatty acids (PUFA). In an additional group of ratio 0.5, 18:2n-6 was partially replaced by its delta 6 desaturation product, 18:3n-6. Biochemical analyses were conducted on 12-day-old pup brains, as well as on samples of maternal milk. No obvious effects on overall pup growth and development were observed, apart from a smaller litter size at ratio 1. Co-variance analysis indicated that increasing the n-3/n-6 ratio was associated with slightly smaller brains, relative to body weight. We found that 18:2n-6 and 20:5n-3 were the predominant n-6 and n-3 FA in the milk; in the brain these were 20:4n-6 and 22:6n-3, respectively. Increasing dietary n-3/n-6 ratios generally resulted in an increase in n-3 FA, with a corresponding decrease in n-6 FA.(ABSTRACT TRUNCATED AT 250 WORDS)
Wainwright
P E
PE
Department of Health Studies, University of Waterloo, Ontario, Canada.
Huang
Y S
YS
Bulman-Fleming
B
B
Dalby
D
D
Mills
D E
DE
Redden
P
P
McCutcheon
D
D
D000818:Animals; D000833:Animals, Suckling / Q000254:growth & development; D001921:Brain / Q000187:drug effects / Q000254:growth & development*; D001923:Brain Chemistry / Q000187:drug effects*; D004041:Dietary Fats / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D008297:Male; D051379:Mice; D008892:Milk / Q000032:analysis; D010712:Phosphatidic Acids / Q000032:analysis*; D010713:Phosphatidylcholines / Q000032:analysis; D010714:Phosphatidylethanolamines / Q000032:analysis
D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D005231:Fatty Acids, Unsaturated; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines