Effects of Intake of Maternal Dietary Elaidic Acids during Pregnancy and Lactation on the Fatty Acid Composition of Plasma, Erythrocyte Membrane, and Brain in Rat Pups

To investigate the effects of a dam’s dietary elaidic acid (EA) intake during pregnancy and lactation on the fatty acid composition of plasma, erythrocyte membrane, and brain in rat pups, we fed two groups of dams either a soybean oil diet (SOD) or a shortening diet (SHD) containing soybean oil (10%) or shortening (10%), respectively. Although EA was not detected in the SOD, EA accounted for 25.3% of all fatty acid content in the SHD. On day 8 after birth, the EA levels in the stomach, plasma, and erythrocyte membrane of pups nursed by the dams fed the SHD were %, %, and %, respectively. Although on day 8 after birth the EA level of the brains of pups nursed by SHD-fed dams was %, EA was not detected on day 21 or day 82 after birth. These results suggest that EA intake during pregnancy and lactation supplies EA to plasma, remains in the erythrocyte membrane of pups, and moves into the brain in early infancy. 1. Introduction Trans fatty acids (TFAs) are created from vegetable oils through hydrogenation. In the trans configuration, the carbon chain extends from opposite sides of the double bond, rendering a straight molecule. Elaidic acid (EA; C18:1) is the principal TFA often found in partially hydrogenated vegetable oils, margarine, and shortening [1, 2]. Young people in Japan have come to prefer a Western-style diet, and now more than 29% of the calories consumed by Japanese people are provided by fat [3]. The consumption of trans fats increases the risk of coronary heart disease (CHD) by raising the levels of LDL cholesterol and lowering the levels of HDL cholesterol [2, 4, 5]. It has been reported that an elevated TFA blood cell content increased the risk of acute coronary syndromes (ACS) [6, 7]. Infants are exposed to TFA before and after birth by the transfer of fatty acids originating from the maternal diet [9]. On average, mature human milk provides 3.7？g？fat/100？mL, representing about 50% of the dietary energy intake of the young infant [10, 11]. Infants receiving human milk ingest levels of TFAs and essential fatty acids that reflect short-and long-term maternal diets [12–14]. Recent studies have indicated that the EA content of the maternal diet may be associated with both maternal and infant body composition in the early postpartum period [15]. We previously reported that dietary fish oil intake during pregnancy and lactation provides more n-3 polyunsaturated fatty acids (PUFA) to pups and alters their brain fatty acid composition [16]. However, it has been reported that prenatal essential fatty acid deficiency may result in myelin with an