Fish nutrient composition: a review of global data from poorly assessed inland and marine species

Abstract

Objective: Our understanding of the nutrient contribution of fish and other aquatic species to human diets relies on nutrient composition data for a limited number of species. Yet particularly for nutritionally vulnerable aquatic food consumers, consumption includes a wide diversity of species whose nutrient composition data are disparate, poorly compiled or unknown.

Design: To address the gap in understanding fish and other aquatic species' nutrient composition data, we reviewed the literature with an emphasis on species of fish that are under-represented in global databases. We reviewed 164 articles containing 1370 entries of all available nutrient composition data (e.g. macronutrients, micronutrients and fatty acids) and heavy metals (e.g. Pb and Hg) for 515 species, including both inland and marine species of fish, as well as other aquatic species (e.g. crustaceans, molluscs, etc.) when those species were returned by our searches.

Results: We highlight aquatic species that are particularly high in nutrients of global importance, including Fe, Zn, Ca, vitamin A and docosahexaenoic acid (DHA), and demonstrate that, in many cases, a serving can fill critical nutrient needs for pregnant and lactating women and young children.

Conclusions: By collating the available nutrient composition data on species of fish and other aquatic species, we provide a resource for fisheries and nutrition researchers, experts and practitioners to better understand these critical species and include them in fishery management as well as food-based programmes and policies.

Keywords: Aquatic food systems; Fish access; Food security; Marine food systems; Nutrition security; Small indigenous species.

Fig. 1

Number of a) studies and b) analyses, as well as c) inland analyses and d) marine analyses. Numbers of analyses refers to the total number of analyses done, which exceeds the number of species analyzed as multiple studies may have analyzed the nutritional composition of the same species, or a study may have compared nutritional composition of the same species across different conditions (e.g., habitats, populations, times of year) resulting in multiple analyses

Fig. 2

Contribution (%) of recommended nutrient intake (RNI)⁽²²⁾ of iron by fish and other aquatic species. Percentages are estimated based on a 50 g/d serving of fish for pregnant and lactating women, a 25 g/d serving for children 6–24 months, and assuming 10 % bioavailability of iron. The RNI for iron for pregnant women is based on the value of 29·4 mg/d for women aged 19–50 years, as no specific value for pregnant women is given. This is in alignment with the Institute of Medicine (IOM) RDA of 27 mg/d for pregnant women⁽²⁴⁾. Iron values and sources are given in Table A2. , Pregnant women; , lactating women; , children 6-11 months; , children 12-24 months

Fig. 3

Contribution (%) of recommended nutrient intake (RNI)⁽²²⁾ of zinc by fish and other aquatic species. Percentages are estimated based on a 50 g/d serving of fish for pregnant and lactating women, a 25 g/d serving for children 6–24 months, and assuming moderate bioavailability. For pregnant and lactating women, zinc contributions were calculated by averaging the requirements throughout the three trimesters of pregnancy, and first 12 months of lactation, given that they vary slightly depending on trimester and month of lactation. Zinc values and sources are given in Table A3. , Pregnant women; , lactating women; , children 6-24 months

Fig. 4

Contribution (%) of mean recommended intake⁽²²⁾ of calcium by fish and other aquatic species. Percentages are estimated based on a 50 g/d serving of fish for pregnant and lactating women, and a 25 g/d serving for children 6–24 months. Calcium values and sources are given in Table A4. , Pregnant women; , lactating women; , children 6-11 months; , children 12-24 months

Fig. 5

Contribution (%) of recommended nutrient intake (RNI)⁽²²⁾ of vitamin A by fish species. Percentage is estimated based on a 50 g/d serving of fish for pregnant and lactating women, and a 25 g/d serving of fish for children 6–24 months. Vitamin A values and sources are given in Table A5. , Pregnant women; , lactating women; , children 6-24 months

Fig. 6

Contribution (%) of daily recommendation of DHA by fish species. The FAO recommends an intake of 200 mg/d of DHA for pregnant and lactating women, and the adequate intake for children 6–23 months is estimated to be 10–12 mg/kg per d⁽²⁵⁾. Based on the work of Bogard et al.⁽¹³⁾, we used a figure of 110 mg DHA/d for young children, which is the midpoint of the recommended range of intakes based on the respective body weights of children at 7 months and children at 23 months at the 50th percentile⁽²⁶⁾. Percentages are estimated based on a 50 g/d serving of fish for pregnant and lactating women, and a 25 g/d serving of fish for children 6–24 months. DHA values and sources are given in Table A6. , Pregnant and lactating women; , children 6-24 months