Fish-based pureed baby foods: A scientific literature review on metal(oid) levels and limited availability in the Spanish market

Fish is a recommended food in early childhood due to its high content of essential nutrients, particularly omega-3 fatty acids, which are positively associated with cognitive development. However, fish may also be a source of exposure to toxic metal(loid)s, such as Hg and As, which can pose health risks. This study had two main objectives: (i) to conduct a literature review on the levels of metal(loid)s in commercial pureed baby foods (PBFs); and (ii) to assess the availability and labelling information of fish-based PBFs in the Spanish market. This study followed the methodology of a scoping review, conducted in accordance with the PRISMA Extension for Scoping Reviews (PRISMA-ScR). The PRISMA 2020 guidelines and checklist were followed throughout the process. On the other hand, the supply of fish-based PBFs in the Spanish market was compiled, as well as information on their labelling. The examined studies (n=11) showed that fish-based PBFs had the highest mean concentrations of As and Hg, while meat- and vegetable-based PBFs showed higher levels of Cd and Pb, sometimes exceeding legal limits. Fish-based PBFs represented only 12.04-13.13 % of the total Spanish market supply, with a fish content frequently around 8%. Most of these products also included potato (≈ 80 %), carrot (≈ 70 %), and rice (≈ 65 %). Despite the well-documented neurodevelopmental benefits of fish consumption during childhood, the limited availability of fish-based PBFs suggests a nutritional gap. While legislation establishes maximum permissible limits for metal(oid)s in baby foods, efforts should focus on minimizing their presence to ensure infant health, following the strategy “Closer to Zero”.