PEDIATRICS Vol. 111 No. 1 January 2003, pp. e39-e44

 

ELECTRONIC ARTICLE

Maternal Supplementation With Very-Long-Chain n-3 Fatty Acids During Pregnancy and Lactation Augments ChildrenÕs IQ at 4 Years of Age

Ingrid B. Helland, MD*,{ddagger}, Lars Smith, PhD¤, Kristin Saarem, PhD||, Ola D. Saugstad, MD, PhD{ddagger} and Christian A. Drevon, MD, PhD*

 

* Institute for Nutrition Research

{ddagger} Department of Pediatric Research

¤ Institute of Psychology, University of Oslo, Oslo, Norway

|| Peter Mšller, avd Orkla, ASA, Oslo, Norway

********see abstract way below*****

DISCUSSION

 

This is the first study to examine the long-term effects on children of maternal supplementation with very-long-chain n-3 PUFAs during pregnancy and lactation. Our present study shows that 4-year-old children have higher mental processing scores when the mothers are supplemented with very-long-chain n-3 PUFAs (from cod liver oil) during pregnancy and lactation, as compared with children of mothers who are supplemented with long-chain n-6 PUFAs (from corn oil).

 

The maternal intake of DHA during pregnancy seems to be important for mental development measured at 4 years of age. Higher maternal intake of DHA results in higher maternal plasma levels and thereby increased transfer of DHA to the fetus.31,37 In an observational study, it was recently reported that stereoacuity at age 3.5 years was enhanced among full-term infants whose mothers had a DHA-rich diet during pregnancy.38 Breastfeeding was also associated with enhanced stereopsis, compared with children who had not been breastfed.38 In our study, at least 76 infants were breastfed at 3 months of age, thereby receiving AA as well as DHA via their mothersÕ milk. However, the infants of cod liver oil-supplemented mothers received approximately 2.7-fold more DHA than infants of corn oil-supplemented mothers postnatal. Approximately half of all of the infants in both groups received cod liver at 3 months of age. However, we did not observe any effect of cod liver oil supplementation to breastfed infants on later mental development.

 

The difference of 4.1 points in the scores on the Mental Processing Composite of the K-ABC between the 2 groups may have limited significance on individual basis but may be of epidemiologic importance. Didactic procedures increasing IQ with 4 points among school children, with no harmful side effects, would immediately be implemented in schools.

 

We also observed a significant correlation between head circumference and mental processing skills. Severely reduced blood flow to the fetus associated with growth retardation may be followed by impairment of intellectual development and partial neurodevelopment delay.39 Reduced supply of DHA and AA may explain some of the neurologic impairment. Children who are born small for gestational age have smaller head circumference than children who are born appropriate for gestational age, even at 13 months of age.40 They also score lower on the Bayley Mental Scale of Infant Development. At school age, children who were born small for gestational age seem to show learning deficits.41,42 Our study is the first to show such a correlation between head circumference at birth and mental processing skills in healthy term infants. Head circumference at 6 months of age has previously been shown to correlate with IQ at 3 years of age.43

 

We furthermore observed a relation between intelligence scores at 4 years of age and concentrations of docosapentaenoic acid n-3 and DHA in plasma phospholipids at 4 weeks of age but not at birth or at 3 months of age. It is possible that the small number of individuals in our groups makes it difficult to find significant correlations at different time points, but it is tempting to assume that DHA may be important for mental development at least during childhood. We will follow up our study population to the age of 7 years to evaluate whether cod liver oil supplementation to pregnant and lactating women will influence long-term mental skills among children.

 

At birth, Osbond and Mead acid correlated negatively with intelligence scores, and these fatty acids have been proposed to be markers of DHA depletion.44 High levels of these fatty acids might also represent nonoptimal ligands for transcription factors, substrates for enzymatic activities, or structural components in the central nervous system.45

 

PEDIATRICS Vol. 111 No. 1 January 2003, pp. e39-e44

 

ELECTRONIC ARTICLE

Maternal Supplementation With Very-Long-Chain n-3 Fatty Acids During Pregnancy and Lactation Augments ChildrenÕs IQ at 4 Years of Age

Ingrid B. Helland, MD*,{ddagger}, Lars Smith, PhD¤, Kristin Saarem, PhD||, Ola D. Saugstad, MD, PhD{ddagger} and Christian A. Drevon, MD, PhD*

 

* Institute for Nutrition Research

{ddagger} Department of Pediatric Research

¤ Institute of Psychology, University of Oslo, Oslo, Norway

|| Peter Mšller, avd Orkla, ASA, Oslo, Norway

 

 

Objectives. Docosahexaenoic acid (DHA; 22:6 n-3) and arachidonic acid (AA; 20:4 n-6) are important for development of the central nervous system in mammals. There is a growth spurt in the human brain during the last trimester of pregnancy and the first postnatal months, with a large increase in the cerebral content of AA and DHA. The fetus and the newborn infant depend on maternal supply of DHA and AA. Our hypothesis was that maternal intake of DHA during pregnancy and lactation is marginal and that high intake of this fatty acid would benefit the child. We examined the effect of supplementing pregnant and lactating women with very-long-chain n-3 polyunsaturated fatty acids (PUFAs; cod liver oil) on mental development of the children, compared with maternal supplementation with long-chain n-6 PUFAs (corn oil).

 

Methods. The study was randomized and double-blinded. Pregnant women were recruited in week 18 of pregnancy to take 10 mL of cod liver oil or corn oil until 3 months after delivery. The cod liver oil contained 1183 mg/10 mL DHA, 803 mg/10 mL eicosapentaenoic acid (20:5 n-3), and a total of 2494 mg/10 mL {sum} n-3 PUFAs. The corn oil contained 4747 mg/10 mL linoleic acid (18:2 n-6) and 92 mg/10 mL {alpha}-linolenic acid (18:3 n-3). The amount of fat-soluble vitamins was identical in the 2 oils (117 µg/mL vitamin A, 1 µg/mL vitamin D, and 1.4 mg/mL dl-{alpha}-tocopherol). A total of 590 pregnant women were recruited to the study, and 341 mothers took part in the study until giving birth. All infants of these women were scheduled for assessment of cognitive function at 6 and 9 months of age, and 262 complied with the request. As part of the protocol, 135 subjects from this population were invited for intelligence testing with the Kaufman Assessment Battery for Children (K-ABC) at 4 years of age. Of the 135 invited children, 90 came for assessment. Six children did not complete the examination. The K-ABC is a measure of intelligence and achievement designed for children aged 2.5 years through 12.5 years. This multisubtest battery comprises 4 scales: Sequential Processing, Simultaneous Processing, Achievement (not used in the present study), and Nonverbal Abilities. The Sequential Processing and Simultaneous Processing scales are hypothesized to reflect the childÕs style of problem solving and information processing. Scores from these 2 scales are combined to form a Mental Processing Composite, which serves as the measure of intelligence in the K-ABC.

 

Results. We received dietary information from 76 infants (41 in the cod liver oil group and 35 in the corn oil group), documenting that all of them were breastfed at 3 months of age. Children who were born to mothers who had taken cod liver oil (n = 48) during pregnancy and lactation scored higher on the Mental Processing Composite of the K-ABC at 4 years of age as compared with children whose mothers had taken corn oil (n = 36; 106.4 [7.4] vs 102.3 [11.3]). The Mental Processing Composite score correlated significantly with head circumference at birth (r = 0.23), but no relation was found with birth weight or gestational length. The childrenÕs mental processing scores at 4 years of age correlated significantly with maternal intake of DHA and eicosapentaenoic acid during pregnancy. In a multiple regression model, maternal intake of DHA during pregnancy was the only variable of statistical significance for the childrenÕs mental processing scores at 4 years of age.

 

Conclusion. Maternal intake of very-long-chain n-3 PUFAs during pregnancy and lactation may be favorable for later mental development of children.