A Randomized Controlled Intervention With Fish Oil Versus Sunflower Oil From 9 to 18 Months of Age: Exploring Changes in Growth and Skinfold Thicknesses

Abstract

n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), from fish oil (FO), in rodents have been shown to reduce adipogenesis. Evidence of an effect on adipose tissue mass in humans is limited, and no studies have specifically aimed to elucidate this in infancy. To explore whether n-3 LCPUFA intake affects adipose tissue growth, we randomly allocated 154 healthy infants to daily supplementation with FO or sunflower oil (SO) from 9 to 18 mo of age and measured z-score changes in various anthropometric assessments of body size and skinfold thicknesses and plasma adipokine concentrations. Among the 133 completing infants, erythrocyte n-3 PUFA increased more in those receiving FO than in infants receiving SO [12.2 Ϯ 0.7 (mean Ϯ SE) versus 2.0 Ϯ 0.4 fatty acid percentage (FA%), p Ͻ 0.001] with a concomitant larger decrease in n-6 PUFA (Ϫ8.9 Ϯ 0.7 versus Ϫ0.9 Ϯ 0.6 FA%, p Ͻ 0.001). We found no association between FO consumption relative to SO consumption and any of the anthropometric measures related to the size of the fat mass, but infants in the FO group had a lower skinfold ratio (triceps/ subscapular) at 18 mo than those in SO group (p ϭ 0.02). Our findings do not support the hypothesis that dietary n-3 LCPUFA is important for infant fat mass, but future studies testing this specifically are warranted. A sedentary lifestyle that favors a positive energy balance is generally acknowledged as the major cause of the increasing prevalence of obesity, but other potential contributing factors are also receiving attention. Among these are the dietary changes in the consumption of polyunsaturated fatty acids (PUFA) toward a higher n-6 and lower n-3 PUFA intake, which has been suggested as a partial explanatory factor (1). Dietary n-3 long-chain PUFA (LCPUFA) in rodents has been shown to prevent diet-induced obesity (2) and has also been reported to enhance fat mass reduction in two randomized weight-loss trials in overweight adults (3) and obese women with type-2 diabetes (4).Early life is a period of rapid growth with major changes in both body size and composition. It is well established that docosahexaenoic acid (DHA, 22:6n-3) is important for, e.g., visual development in infancy (5), but it is presently unknown to what extent n-3 LCPUFA should be considered relevant with respect to adiposity. The natural content of n-3 PUFA in breast milk has been found to be positively associated with infant weight gain in preterm (6) but not term-born infants (7). Furthermore, two intervention studies giving n-3 LCPUFA to pregnant and/or lactating mothers suggest a programming effect on later infant BMI, although in opposite directions (8,9). However, no studies have to our knowledge aimed specifically to investigate whether dietary n-3 LCPUFA in early life is associated with the size of the fat mass per se.Inspired by the clear finding in rodents, this study was conducted to attempt to elucidate whether growth and fat deposition in healthy Danish infants during the complementary feeding period, 9 -18 mo of age, are associ...

Effects on metabolic markers are modified by PPARG2 and COX2 polymorphisms in infants randomized to fish oil

“…Median plasma insulin at 9 months was lower in the FO group, mainly due to a larger spread. The PUFA intake was slightly higher in the FO group, and fish intake was also somewhat skewed with a higher intake in the FO group and more infants who had not been introduced to fish in the SO group, but the RBC fatty acid composition was similar (Andersen et al 2011).…”

“…The median intake of intervention oil was 3.8 (3.2-4.2) g/day, which provided around 630 mg/day EPA and 620 mg/day of DHA (Andersen et al 2011). Eicosapentaenoic acid and DHA in RBC were significantly increased in the FO group, EPA by 5.5 (4.1-7.4) FA % and DHA by 4.8 ± 0.3 FA %, relative to the changes in SO group (EPA: 0.5 (0.0-1.1) FA %, DHA: 1.0 ± 0.3 FA %.…”

“…H-A-2007-0088) and registered at ClinicalTrials.gov as NCT 00631046. The study design and methods are described in detail by Andersen et al (2011).…”

“…The oils were provided in ten dark bottles of similar appearance (1.5 L in total) and all bottles, empty or containing oil leftovers were returned for the assessment of compliance at the 18 months examination. The group allocation was performed blinded and based on a computer-generated block randomization with varying block sizes of 4, 6, 8, and 10 (www.randomization.com) as described elsewhere (Andersen et al 2011). …”

“…The anthropometric measurements were taken by trained investigators as described in detail by Andersen et al (2011). Recumbent length was measured to the nearest millimeter on a wooden measuring board (Force Technology, Brøndby, Denmark).…”