Portuguese preschool children: Benefit (EPA+DHA and Se) and risk (MeHg) assessment through the consumption of selected fish species.

This study aimed to assess the risk-benefit balance associated to fish consumption by Portuguese preschool children. For this purpose, databases (from IPMA and literature) were mined and mathematically processed by a model based on the Extreme Value Theory assuming consumption scenarios. Eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) and selenium (Se) and methylmercury (MeHg) were selected as critical components of fish, given their health impact and significant contents in some fish species. Assessment also took into account that Se may protect against MeHg toxicity. With exception of blue shark, Se Health Benefit Value (Se-HBV), was always positive (ranging between 3.3 and 14.9) and Se:MeHg ratio was always higher than one (3.8 to 32.3). It was also estimated that the deleterious effects of MeHg on children IQ were offset by the beneficial impact of EPA+DHA in fish except for grilled black scabbardfish consumed every day. Blue shark, regardless of the culinary treatment, yielded very high probabilities of exceeding MeHg TWI (higher than 84 % with a single weekly meal), thus raising serious concerns. EPA+DHA benefits were high in salmon regardless of culinary treatment (> 84 %). Fish consumption by children is advisable with exception of blue shark and boiled and grilled tuna.