This proposal builds on studies already completed or ongoing within ALSPAC regarding essential fatty acid status and behavioural outcomes during development. Several levels of data predict that greater omega-3 fatty acid intake and greater serum status will be beneficial in protecting individuals from developing substance misuse disorders, in particular alcohol misuse. We have reported that deficient omega-3 intake during pregnancy increases risk for low verbal IQ, suboptimal motor development and suboptimal social interactions. These parameters have been described as early markers of an adverse developmental trajectory.

In addition, a phenotype characterized by a low level of response to first exposures to alcohol has been well characterized in the ALSPAC cohort by Marc Schuckit and shown to be predictive of alcohol misuse at age 15. A plausible biological mechanism partially underlying this phenotype is hyper activity of the endocannabinoid system because it is associated with increased tolerance to alcohol and lower levels of response in both animal models and pilot clinical studies. Endocannabinoids are produced from phosholipid precursors in membranes and are comprised of arachidonic acid, an omega-6 essential fatty acid. We have demonstrated in animal studies that dietary depletion of omega-3 fatty acids causes reciprocal replacement with omega-6 fatty acids in phospholipids which, in turn, causes 2-3 fold greater endocannabinoid activity in liver and brain.

Aims: Determine if essential fatty status of RBC's during pregnancy, or in umbilical serum, or in 7 or 13 year old serum samples predict parameters of alcohol use or pheonotypic response to alcohol, throughout development.

Long chain essential fatty acid status is determined by a combination of direct dietary intakes and genetic variation in the FADS 1-2 gene complex, which enzymes that desaturate short chain precursors to long chain polyunsaturates. Thus, these determinants of serum essential fatty acid composition will be examined as predictive determinants of the parameters of alcohol use and response. These genetic variants are currently being examined as determinants of serum and maternal RBC fatty acid composition. Potential confounders including parameters of social, educational, smoking and nutritional status will be examined.

All data are or will be available, with the exception of fatty acid levels at age 13.We assume plasma will be available at this stage and a request has gone to the SR.If approved, the plasma will be assayed for fatty acid composition using the automated robotic high-throughput methodology established by the Section of Nutritional Neurosciences, NIAAA. NIH for the n = 4,090 umbilical cord and n = 6,500 7 year old serum samples.Validation of a method of high-throughput quantitative analysis of endocannabinoids in 250 ul of plasma is currently underdevelopment in this laboratory.If validated, endocannabinoid measures, in addition to the fatty acid compositional measures will be added to the rich ALSPAC database.