27 June 2013 - Oxford University - ‘Low Omega-3 in children could help to explain poor learning and behaviour’

An Oxford University study has shown that a group of UK schoolchildren, many of whom were struggling with their reading, had low levels of key Omega-3 fatty acids in their blood. The long-chain Omega-3 fats (EPA and DHA) found in fish, seafood and some algae, are essential for the brain’s structure and function as well as for maintaining a healthy heart and immune system. This latest research, published in the journal PLOS One, found that children’s blood levels of the long-chain Omega-3 DHA (the form found in most abundance in the brain) ‘significantly predicted’ how well they were able to concentrate and learn.

The study is one of the first to evaluate blood Omega-3 levels in UK schoolchildren. Parents also reported on their child’s diet, revealing to the researchers that almost nine out of ten children in the sample ate fish less than twice a week, and nearly one in ten never ate fish at all. The government’s guidelines for a healthy diet recommend at least two portions of fish a week.  This is because like vitamins, omega-3 fats have to come from our diets – and although humans can in theory make some EPA and DHA from shorter-chain omega-3 (found in some vegetable oils), research has shown this conversion is not reliable, particularly for DHA, say the researchers.

Blood samples were taken from 493 schoolchildren, aged between seven and nine years, from 74 mainstream schools in Oxfordshire.  All of the children were thought to have below-average reading skills, based on national assessments at the age of seven or their teachers’ current judgements. Analyses of their blood samples showed that, on average, just under 2 per cent of the children’s total blood fatty acids were Omega-3 DHA (Docosahexaenoic acid) and 0.5 per cent were Omega-3 EPA (Eicosapentaenoic acid), with a total of 2.45 per cent for these long-chain Omega-3 combined. This is below the minimum of 4 per cent recommended by leading scientists to maintain cardiovascular health in adults, with 8-12 per cent regarded as optimal for a healthy heart, the researchers reported.

Co-author Professor Paul Montgomery, from the Centre for Evidence- Based Intervention at the University of Oxford, said: ‘From a sample of nearly 500 schoolchildren, we found that levels of Omega-3 fatty acids in the blood significantly predicted a child’s behaviour and ability to learn.

"Higher levels of Omega-3 in the blood, and DHA in particular, were associated with better reading and memory, as well as with fewer behaviour problems as rated by parents and teachers.

"These results are particularly noteworthy given that we had a restricted range of scores – especially with respect to blood DHA - but also for reading ability, as around two-thirds of these children were still reading below their age-level when we assessed them for this study.  Although further research is needed, we think it is likely that these findings could be applied generally to schoolchildren throughout the UK.’

Co-author Dr Alex Richardson, from the Centre for Evidence-Based Intervention at the University of Oxford, added: ‘The longer term health implications of such low blood Omega 3 levels in children obviously can’t be known. But this study suggests that many, if not most UK children, probably aren’t getting enough of the long-chain Omega 3 we all need for a healthy brain, heart and immune system.  That gives serious cause for concern – especially as we found that lower blood DHA was linked with poorer behaviour and learning in these children.

‘Most of the children we studied had blood levels of long-chain Omega-3 that in adults would indicate a high risk of heart disease. This was consistent with their parents’ reports that most of them failed to meet current dietary guidelines for fish and seafood intake. Similarly, few took supplements or foods fortified with these Omega-3.’

Technical advances in recent years have enabled the measurement of individual Omega-3 and other fatty acids from fingerstick blood samples. ‘These new techniques have been revolutionary – because in the past, blood samples from a vein were needed for assessing fatty acids, and that has seriously restricted research into the blood Omega-3 status of healthy UK children until now,’ said Dr Richardson.

The authors believe these findings could have relevance for the general UK population, as the spread of scores in this sample was within the normal population range for both reading and behaviour. However, they caution that their relevance to more ethnically diverse populations cannot be assumed, as some genetic differences can affect how Omega-3 fatty acids are metabolised. Most of the children participating in this study were white British.

Notes for Editors

*The paper ‘Low blood long chain Omega-3 fatty acids in UK children are associated with poor cognitive performance and behaviour’ by Montgomery et al appeared in PLOS One on June 24th

*DOLAB (DHA Oxford Learning and Behaviour)

The research was carried out as part of the DHA Oxford Learning and Behaviour (DOLAB) studies, involving researchers in the Centre for Evidence Based Intervention at the University of Oxford, in association with Oxfordshire Local Authority.

The children included a nationally representative percentage from low-income households. The study found no significant differences in blood Omega-3 levels relating to gender, nor to the children’s social and economic backgrounds.

For more information, see http://www.spi.ox.ac.uk/research/centre-for-evidence-based-intervention/dolab-studies.html