Bioequivalence of dietary alpha-linolenic and docosahexaenoic acids as sources of docosahexaenoate accretion in brain and associated organs of neonatal baboons.
The dietary bioequivalence of alpha-linolenic (LNA) and docosahexaenoic acids (DHA) as substrates for brain and retinal n-3 fatty acid accretion during the brain growth spurt is reported for neonatal baboons who consumed a long-chain-polyunsaturate free commercial human infant formula with a n-6/n-3 ratio of 10:1. Neonates received oral doses of 13C-labeled fatty acids (LNA*) or (DHA*) at 4 wk of age, and at 6 wk brain (occipital cortex), retina, retinal pigment epithelium, liver, erythrocytes, and plasma were analyzed. In the brain, 1.71% of the preformed DHA* dose was detected, whereas 0.23% of the LNA* dose was detected as DHA*, indicating that preformed DHA is 7-fold more effective than LNA-derived DHA as a source for DHA accretion. In LNA*-dosed animals, DHA* was greater than 60% of labeled fatty acids in all tissues except erythrocytes, where docosapentaenoic acid was 55%. Estimates using dietary LNA levels as tracees indicate that brain turnover of DHA is less than 5% per week between weeks 4 and 6 of life. For retina and retinal pigment epithelium, preformed DHA was at levels 12-fold and 15-fold greater than LNA-derived DHA. Liver, plasma, and erythrocytes ratios were 27, 29, and 51, respectively, showing that these pools do not parallel tissue metabolism of a single dose of omega-3 fatty acids. The distributions of labeled fatty acids for LNA*-dosed animals were similar, in the order DHA > DPA > EPA > LNA, except for erythrocytes where docosapentaenoic acid predominated. These are the first direct measurements of the bioequivalence of DHA and LNA in neonatal primate brain and associated tissues.
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H M
HM
Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA.
Bernardo
L
L
Mirmiran
M
M
Ma
X H
XH
Corso
T N
TN
Nathanielsz
P W
PW
Brenna
J T
JT
D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D004281:Docosahexaenoic Acids / Q000097:blood / Q000493:pharmacokinetics*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D007225:Infant Food; D008099:Liver / Q000378:metabolism; D008297:Male; D009778:Occipital Lobe / Q000378:metabolism*; D009928:Organ Specificity; D010215:Papio; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D012160:Retina / Q000378:metabolism; D013810:Therapeutic Equivalency; D017962:alpha-Linolenic Acid / Q000097:blood / Q000493:pharmacokinetics*
D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids