Optimizing DHA levels in piglets by lowering the linoleic acid to alpha-linolenic acid ratio.
We examined the effect of altering the linoleic acid (LA, 18:2n-6) to alpha-linolenic acid (ALA, 18:3n-3) ratio in the dietary fats of 3 day old piglets fed formula for 3 weeks. The LA-ALA ratios of the experimental formulas were 0.5:1, 1:1, 2:1, 4:1, and 10:1. The level of LA was held constant at 13% of total fats while the level of ALA varied from 1.3% (10:1 group) to 26.8% (0.5:1 group). Incorporation of the n-3 long chain PUFA EPA and 22:5n-3 into erythrocytes, plasma, liver, and brain tissues was linearly related to dietary ALA. Conversely, incorporation of DHA into all tissues was related to dietary ALA in a curvilinear manner, with the maximum incorporation of DHA appearing to be between the LA-ALA ratios of 4:1 and 2:1. Feeding LA-ALA ratios of 10:1 and 0.5:1 resulted in lower and similar proportions of DHA in tissues despite the very different levels of dietary ALA (1.3 vs. 26.8% of total fats, respectively). These results are relevant to term infant studies in that they confirm our earlier findings of the positive effect on DHA status by lowering the LA-ALA ratio from 10:1 to 3:1 or 4:1, and they predict that ratios of LA-ALA below 4:1 would have little further beneficial effect on DHA status.
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Cordula
C
Department of Paediatrics and Child Health, Flinders Medical Centre, Bedford Park, South Australia 5042, Australia.
Neumann
Mark A
MA
Makrides
Maria
M
Gibson
Robert A
RA
D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D001923:Brain Chemistry / Q000187:drug effects; D002849:Chromatography, Gas; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000097:blood / Q000378:metabolism*; D004912:Erythrocytes / Q000737:chemistry / Q000187:drug effects; D005260:Female; D019787:Linoleic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D008099:Liver / Q000737:chemistry / Q000187:drug effects; D009747:Nutritional Physiological Phenomena; D013552:Swine / Q000097:blood / Q000254:growth & development / Q000378:metabolism*; D017962:alpha-Linolenic Acid / Q000008:administration & dosage / Q000494:pharmacology*
D004041:Dietary Fats; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D019787:Linoleic Acid