There have been several studies showing the effects of vitamin supplementation, nutrient deficiency and recent dietary intake on IQ in children [see 1 for a review]. We have recently shown in the ALSPAC cohort that overall dietary patterns in early childhood are associated with both later child behaviour and school performance [2,3]. There appears to be little known about the long-term effects of early diet (with the exception of infant feeding) on later child cognition, as assessed by IQ. The use of dietary patterns aims to overcome the inherent problems of examining individual food and nutrients associations, namely, the inter-correlations between these foods and nutrients. The proposed analysis provides a novel approach to examining the effects of dietary intake on cognitive development.

A preliminary analyses assessing the effects of childhood dietary patterns on IQ has already performed in order to feed into a grant proposal to be submitted to NIH in Feb 08 by Tomas Paus (Nottingham), a primary aim of which is to evaluate the role of nutrition during the first five years of life on brain structure in adolescence.

At his request, I examined the associations between dietary patterns in early childhood (at ages 3, 4, 7 and 8 years [4,5]) and overall IQ assessed at 8 years of age. Initial results suggest that there may be an effect of overall dietary patterns in childhood and IQ. In particular a 1 SD increase in the 'processed' component score at each age (3, 4, 7 and 8) was associated with a decrease of between 2 and 4 points on the WISC IQ scale, while a 1 SD increase in 'health conscious' component score at each age resulted in a 2 point increase. After adjustment for a limited number of confouding or mediating factors the effect sizes were attenuated, though strong relationships remained the 3-year data; as such further analyses is required to take into account additional factors which may be important after a thorough review of the literature. This will determine whether the observed effects are real or due to residual confounding.

Proposed further anlaysis will include:

1. Examining the verbal and performance components of the WISC;

2. Examining the results of the subtests of the WISC;

3. Further adjustment for other factors, including maternal diet, aspects of which have been shown to be associated with IQ in this sample [6];

4. Using cut-offs for IQ in order to determine the risk of poor performance.

Although this work is unfunded it will be of particular use to the NIH grant and is a natural follow-on to the work constituting my PhD. It will also feed into other funding opportunities to investigate the effects of diet on other cognitive and neuro-developmental outcomes.