Effect of Dietary α-Linolenic Acid Intake on Incorporation of Docosahexaenoic and Arachidonic Acids into Plasma Phospholipids of Term Infants
Sauerwald, T.U., Hachey, D.L., Jensen, C.L., Chen, H., Anderson, R.E., and Heird, W.C. 1996. Effect of Dietary α-Linolenic Acid Intake on Incorporation of Docosahexaenoic and Arachidonic Acids into Plasma Phospholipids of Term Infants. Lipids. 31:S131-S135.
The ability of infants to convert the precursor essential fatty acids, α-linolenic (ALA) and linoleic acid (LA), to longer chain fatty acids docosahexaenoic (DHA) and arachidonic acids (AA), may be inadequate to meet the considerable needs of these fatty acids in developing tissues. The present study examined the fractional rates of conversion of ALA and LA to DHA and AA respectively, and the fractional rates of incorporation of DHA and AA into plasma phospholipids in a group of 27 healthy three-week old term infants who received ALA and LA from birth. All infants were able to convert ALA to DHA and LA to AA. While fractional conversion to DHA was not different among groups, the fractional conversion to AA was less in infants who received higher ALA intakes, as was the fractional rate of incorporation of AA into plasma phospholipid. While the data reported apply strictly to only the plasma phospholipids fraction, it is likely that they are applicable to other fractions as well. Unfortunately, this and other reported data are not sufficient to calculate or estimate the amounts of long-chain polyunsaturated fatty acids synthesized daily, largely because there are no data concerning the magnitude of the precursor pool and synthesized fatty acids of any lipid fraction. In this study, a dietary ALA intake of 3.2 vs. 0.4% of total fat resulted in about a 2.5-fold greater rate of incorporation of DHA into plasma phospholipid while at the same time depressing both the rate of conversion of LA to AA, and the rate of incorporation of AA into the plasma phospholipid fraction, by about the same percentage.