Effects of Omega-3 Fatty Acids Supplementation on Brain and Behaviour in Healthy Children.

Background It has been established that a safe environment, adequate stimulation, and parental care play a major role in brain development. An adequate diet is also critically important for brain development in growing children. It has been suggested that omega-3 fatty acids are essential to human health as well as cognitive development. Omega-3 acid is important during prenatal human brain development, especially for synaptogenesis. Levels of omega-3 amino acids in during prenatal and early postnatal (breastfeeding) periods depend on their levels in maternal circulation. Later on, omega-3 must be present in the child's diet. It seems that omega-3 deficiency may associated with impaired visual acuity, cognition, cerebellar dysfunction and other neurological disorders (Haag, 2003; Review). Thus, omega-3 supplementation may be beneficial in children with poor diet, often associated with a lower socioeconomic level (Northstone et al. 2008).

Aims and Design We assessed effects of Omega-3 supplementation on brain and behaviour of 40 healthy children 9-to-12 years old. Since diet supplementation may be beneficial in particular to children with poor diet, we recruited children in less well-off neighbourhoods, as determined by the Index of Multiple Deprivation 2007. Our aim was to examine differences on cognitive performance pre and post diet supplementation.

The brain structure was assessed using magnetic resonance imaging (MRI). Cognitive abilities as well as behavioural problems were assessed using a comprehensive battery of tests and questionnaires. To evaluate the effectiveness of the supplementation, we collected a blood sample to investigate the fatty acids level in the blood. The above assessments were carried out twice: before and after a 3-month dietary intervention.

The dietary intervention included a daily use, for a period of three months, of margarine enriched (Experimental group) or not (placebo group) with Omega-3 fatty acids. We hypothesized that this intervention will improve some cognitive deficits (such as attention, processing speed) and behavioural symptoms (e.g. depression, aggressiveness, impulsivity) together with an impact on brain structure (e.g. white-matter properties related to myelination).

Experimental Protocol Each participant participated in two phases: a clinical assessment phase (to assure exclusion and inclusion criteria) and an experimental phase. The experimental phase consisted of the baseline (pre-intervention) assessment, the diet intervention (3 months) and the post-intervention assessment.

At baseline, both groups (enriched diet and placebo) underwent a cognitive assessment and MRI. Parents were asked to complete a questionnaire about the child's behaviour and some demographical data such as number of children, education etc. Children were also asked to provide a blood sample, which was taken by a fully trained and licensed team member.

After the baseline assessment, experimental group (n=20) and control group (n=20) followed a diet supplementation with omega-3 fatty acids or placebo diet respectively. The intervention lasted for three months and then the tests were re-administered for both groups (cases and controls). Parents were also asked to complete a brief questionnaire to measure children's behaviour.