The effect of Atlantic salmon consumption on the cognitive performance of preschool children - A randomized controlled trial.

BACKGROUND AND AIMS: Long chain polyunsaturated n-3 fatty acids (LC-PUFA) are of functional and structural importance for brain development. Observational studies have shown positive relations between fatty fish consumption and cognitive performance in children, but Results from intervention studies using supplementary n-3 LC-PUFA are conflicting. Salmon is a good source of n-3 LC-PUFA, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We tested the hypothesis that an increased dietary salmon intake results in better cognitive outcomes than a meat based diet. METHODS: Children (n = 205, age 4-6 years) in this trial were individually randomized to eating meals containing farmed Atlantic salmon or meat three times weekly for 16 weeks. Pre- and post-intervention a cognitive test (Wechsler Preschool and Primary Scale of Intelligence, 3rd edition, WPPSI-III) and a fine-motor coordination test (Nine Hole Peg Test, 9-HPT) were performed. Biochemical analyses included glycerophospholipid fatty acid profiles in plasma and cheek cells, serum 25-hydroxyvitamin D, and urinary iodine concentration. Dietary intake before and during the study were determined using food frequency questionnaires. RESULTS: Intakes of EPA, DHA, vitamin D and iodine were higher in the salmon than the meat group, but on biomarker level only EPA and DHA increased significantly in the salmon group compared to the meat group (p < 0.001). In general linear models no significant differences between the intervention groups were found in the scale scores of the WPPSI-III tests and the 9-HPT. In analyses of the raw scores, the salmon group showed significantly better improvement in two of the eight raw scores compared to the meat group (symbol search p = 0.038, picture concepts p = 0.047). CONCLUSIONS: Intake of farmed Atlantic salmon led to a greater increase of the raw scores of the picture concept and symbol search subtests, while in the six other subtests raw scores were not different between the groups. This might indicate a modest positive association of salmon intake with the performance of preschool children in some subtests evaluating fluid intelligence but does not suggest an influence on global IQ development. CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE: ClinicalTrials.gov registration number: NCT01951937.

Maternal Iodine Status is Associated with Offspring Language Skills in Infancy and Toddlerhood.

Inadequate iodine status affects the synthesis of the thyroid hormones and may impair brain development in fetal life. The aim of this study was to explore the association between maternal iodine status in pregnancy measured by urinary iodine concentration (UIC) and child neurodevelopment at age 6, 12 and 18 months in a population-based cohort. In total, 1036 families from nine locations in Norway were enrolled in the little in Norway cohort. The present study includes n = 851 mother-child pairs with singleton pregnancies, no use of thyroid medication in pregnancy, no severe genetic disorder, data on exposure (UIC) in pregnancy and developmental outcomes (Bayley Scales of Infant and Toddler Development, third edition). Data collection also included general information from questionnaires. We examined associations between UIC (and use of iodine-containing supplements) and repeated measures of developmental outcomes using multivariable mixed models. The median UIC in pregnancy was 78 µg/L (IQR 46⁻130), classified as insufficient iodine intake according to the WHO. Eighteen percent reported use of iodine-containing multisupplements. A UIC below ~100 was associated with reduced receptive (p = 0.025) and expressive language skills (p = 0.002), but not with reduced cognitive or fine- and gross motor skills. Maternal use of iodine-containing supplements was associated with lower gross motor skills (b = -0.18, 95% CI = -0.33, -0.03, p = 0.02), but not with the other outcome measures. In conclusion, an insufficient iodine intake in pregnancy, reflected in a UIC below ~100 µg/L, was associated with lower infant language skills up to 18 months. The use of iodine-containing supplements was not associated with beneficial effects.

Maternal DHA Status during Pregnancy Has a Positive Impact on Infant Problem Solving: A Norwegian Prospective Observation Study.

Docosahexaenoic acid (DHA, 22:6, n-3) is a long-chain polyunsaturated fatty acid necessary for normal brain growth and cognitive development. Seafood and dietary supplements are the primary dietary sources of DHA. This study addresses the associations between DHA status in pregnant women and healthy, term-born infant problem-solving skills assessed using the Ages and Stages Questionnaire. The fatty acid status of maternal red blood cells (RBCs) was assessed in the 28th week of gestation and at three months postpartum. The infants’ fatty acid status (RBC) was assessed at three, six, and twelve months, and problem-solving skills were assessed at six and twelve months. Maternal DHA status in pregnancy was found to be positively associated with infants’ problem-solving skills at 12 months. This association remained significant even after controlling for the level of maternal education, a surrogate for socio-economic status. The infants’ DHA status at three months was associated with the infants’ problem solving at 12 months. The results accentuate the importance for pregnant and lactating women to have a satisfactory DHA status from dietary intake of seafood or other sources rich in DHA.

Design of the FINS-TEENS study: A randomized controlled trial assessing the impact of fatty fish on cognitive performance in adolescents.

AIMS: To describe the rationale, study design, population and dietary compliance in a randomized controlled trial (RCT) investigating the effect of fatty fish on cognitive performance and mental health in adolescents. METHOD: In the Fish Intervention Studies-TEENS (FINS-TEENS) study we individually randomized 478 adolescents (14-15-year-olds) from eight secondary schools in Norway to receive school meal lunches with fatty fish or meat or n-3 supplements three times a week for 12 weeks. Demographic factors, psychological tests and biological measures were collected pre-and post-intervention. Duplicate portions of lunch meals were collected and individual intake recorded throughout the study. RESULTS: In total, 481 out of 785 adolescents (61%) agreed to participate and 34 (7%) dropped out. Breakfast consumption was the only group difference in background characteristics. Analyses of selected nutrients in the lunch meals showed higher levels of n-3 fatty acids, vitamin D and n-6 fatty acids in the fish compared to the meat meals. Dietary compliance (score 0-144) revealed that the intake in the Fish group (mean = 59, standard deviation (SD) = 35) were lower than in the Meat group (mean = 83, SD = 31, p < 0.01) and Supplement group (mean = 105, SD = 25, p < 0.01). CONCLUSIONS: The results show that it is possible to conduct a RCT with fatty fish in a school-based setting. The results also emphasize the importance of collecting detailed records of dietary compliance, as this information is important when interpreting and analysing the outcome of dietary interventions.

Reduced bone resorption by intake of dietary vitamin D and K from tailor-made Atlantic salmon: A randomized intervention trial.

Suboptimal vitamin D status is common among humans, and might increase bone resorption with subsequent negative effects on bone health. Fatty fish, including Atlantic salmon, is an important dietary vitamin D source. However, due to a considerable change in fish feed composition, the contribution of vitamin D from salmon fillet has been reduced. The main objective was to investigate if intake of vitamin D3 enriched salmon or vitamin D3 tablets decreased bone biomarkers (urinary N-telopeptides, deoxypyridinoline, serum bone-specific alkaline phosphatase, and osteocalcin) compared to a low vitamin D3 intake. The 122 healthy postmenopausal women included in this 12 weeks intervention trial were randomized into four groups: three salmon groups (150 grams/two times/week) and one tablet group (800 IU vitamin D and 1000 mg calcium/day). The salmon groups also received calcium supplements. The salmon had three different vitamin D3/vitamin K1 combinations: high D3+high K1, low D3+high K1, or high D3+low K1. Increased intake of salmon containing high levels of vitamin D3 (0.35-0.38 mg/kg/fillet) and supplements with the same weekly contribution had a positive influence on bone health as measured by bone biomarkers in postmenopausal women. Consequently, an increased level of vitamin D3 at least to original level in feed for salmonids will contribute to an improved vitamin D3 status and may improve human bone health.

Intake of a Western diet containing cod instead of pork alters fatty acid composition in tissue phospholipids and attenuates obesity and hepatic lipid accumulation in mice.

The content of the marine n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is far lower in lean than in fatty seafood. Cod filets contain less than 2g fat per kg, whereof approximately 50% is EPA and DHA. However, a large fraction of these n-3 PUFAs is present in the phospholipid (PL) fraction and may have high bioavailability and capacity to change the endocannabinoid profile. Here we investigated whether exchanging meat from a lean terrestrial animal with cod in a background Western diet would alter the endocannabinoid tone in mice and thereby attenuate obesity development and hepatic lipid accumulation. Accordingly, we prepared iso-caloric diets with 15.1 energy (e) % protein, 39.1 e% fat and 45.8 e% carbohydrates using freeze-dried meat from cod filets or pork sirloins, and using a combination of soybean oil, corn oil, margarine, milk fat, and lard as the fat source. Compared with mice receiving diets containing pork, mice fed cod gained less adipose tissue mass and had a lower content of hepatic lipids. This was accompanied by a lower n-6 to n-3 ratio in liver PLs and in red blood cells (RBCs) in the mice. Furthermore, mice receiving the cod-containing diet had lower circulating levels of the two major endocannabinoids, N-arachidonoylethanolamine and 2-arachidonoylglycerol. Together, our data demonstrate that despite the relatively low content of n-3 PUFAs in cod fillets, the cod-containing diet could exert beneficial metabolic effects.

Docosahexaenoic Acid Status in Pregnancy Determines the Maternal Docosahexaenoic Acid Status 3-, 6- and 12 Months Postpartum. Results from a Longitudinal Observational Study.

BACKGROUND: Essential fatty acid status as well as docosahexaenoic acid (DHA, 22:6n-3) declines during pregnancy and lactation. As a result, the DHA status may not be optimal for child development and may increase the risk for maternal postpartum depression. The objective of this study was to assess changes in the maternal fatty acid status from pregnancy to 12 months postpartum, and to study the impact of seafood consumption on the individual fatty acid status. METHODS: Blood samples and seafood consumption habits (gestation week 28, and three-, six- and 12 months postpartum) were collected in a longitudinal observational study of pregnant and postpartum women (n = 118). Multilevel linear modeling was used to assess both changes over time in the fatty acid status of red blood cells (RBC), and in the seafood consumption. RESULTS: Six fatty acids varied the most (>80%) across the four time points analyzed, including the derivative of the essential α-linoleic acid (ALA, 18:3n-3), DHA; the essential linoleic acid (LA, 18:2 n-6); and the LA derivative, arachidonic acid (AA, 20:4n-6). Over all, a large variation in individuals' DHA- and AA status was observed; however, over the 15-month study period only small inter-individual differences in the longitudinal trajectory of DHA- and AA abundance in the RBC were detected. The median intake of seafood was lower than recommended. Regardless, the total weekly frequency of seafood and eicosapentaenoic acid (EPA, 20:5n-3)/DHA-supplement intake predicted the maternal level of DHA (µg/g RBC). CONCLUSION: The period of depletion of the maternal DHA status during pregnancy and lactation, seem to turn to repletion from about six months postpartum towards one year after childbirth, irrespective of RBC concentration of DHA during pregnancy. Seafood and EPA/DHA-supplement intake predicted the DHA levels over time. TRIAL REGISTRATION: www.helseforskning.etikkom.no 2009/570/REC, project number: 083.09.

Lean-seafood intake reduces cardiovascular lipid risk factors in healthy subjects: results from a randomized controlled trial with a crossover design.

BACKGROUND: Observational studies have strongly indicated an association between fish consumption and reduced risk of cardiovascular disease, but data from randomized controlled trials have been inconclusive. OBJECTIVE: Our primary outcome in this study was to elucidate the potentials of the 2 main dietary protein sources lean seafood and nonseafood to modulate fasting and postprandial lipids in healthy subjects. We hypothesized that lean-seafood intake would reduce cardiovascular lipid risk factors in healthy subjects more than would the intake of nonseafood protein sources. DESIGN: This study was a randomized controlled trial with a crossover design. After 3-wk run-in periods and separated by a 5-wk washout period, 20 healthy subjects (7 men and 13 women) consumed 2 balanced diets that varied in main protein sources (60% of total dietary proteins from lean-seafood or nonseafood sources for 4 wk). At days 1 and 28 of each intervention, fasting and postprandial blood samples were collected before and after consumption, respectively, of test meals with cod or lean beef. RESULTS: Relative to the nonseafood intervention, the lean-seafood intervention reduced fasting (relative difference by diets: 0.31 mmol/L; P = 0.03) and postprandial (P = 0.01) serum triacylglycerol concentrations. The lower serum triacylglycerol concentration was associated with reduced fasting triacylglycerol in chylomicrons and very-low-density lipoproteins (VLDLs) (P = 0.004), reduced fasting VLDL particle size (P = 0.04), and a reduced postprandial concentration of medium-sized VLDL particles (P = 0.02). The lean-seafood intervention prevented the elevated ratio of total cholesterol to HDL cholesterol in the fasted serum (P = 0.03) and postprandial serum (P = 0.01) that was observed after the nonseafood intervention. CONCLUSION: The dietary protein source determines fasting and postprandial lipids in healthy individuals in a manner that may have an effect on the long-term development of cardiovascular disease. This study was registered at clinicaltrials.gov as NCT01708681.

Low omega-3 index in pregnancy is a possible biological risk factor for postpartum depression.

BACKGROUND: Depression is a common disorder affecting 10-15% women in the postpartum period. Postpartum depression can disrupt early mother-infant interaction, and constitutes a risk factor for early child development. Recently, attention has been drawn to the hypothesis that a low intake of seafood in pregnancy can be a risk factor for postpartum depression. Seafood is a unique dietary source of the marine omega-3 fatty acids and is a natural part of a healthy balanced diet that is especially important during pregnancy. METHODS: In a community based prospective cohort in a municipality in Western Norway, we investigated both nutritional and psychological risk factors for postpartum depression. The source population was all women who were pregnant within the period November 2009 - June 2011. The fatty acid status in red blood cells was assessed in the 28(th) gestation week and participants were screened for postpartum depression using the Edinburgh Postnatal Depression Scale (EPDS) three months after delivery. The aim of the present study was to investigate if a low omega-3 index in pregnancy is a possible risk factor for postpartum depression. RESULTS: In a simple regression model, the omega-3 index was associated with the EPDS score in a nonlinear inverse manner with an R square of 19. Thus, the low omega-3 index explained 19% of the variance in the EPDS score. The DPA content, DHA content, omega-3 index, omega-3/omega-6 ratio, total HUFA score, and the omega-3 HUFA score were all inversely correlated with the EPDS score. The EPDS scores of participants in the lowest omega-3 index quartile were significantly different to the three other omega-3 index quartiles. CONCLUSION: In this study population, a low omega-3 index in late pregnancy was associated with higher depression score three months postpartum.