Joint FAO/WHO Expert Consultation on the Risks and Benefits of Fish Consumption: Meeting report, Rome, 9–13 October 2023

Evolving science and debate concerning the benefits and risks of consuming fish have resulted in confusion over the years, and national and international food safety agencies have recognized the need to provide useful, clear and relevant information in this regard to consumers. In October 2023, FAO and WHO held the second Joint FAO/WHO Expert Consultation on the Risks and Benefits of Fish Consumption to analyse new scientific evidence on the matter and draw relevant conclusions and recommendations. The expert consultation was supported by the Background Document on the Risks and Benefits of Fish Consumption, containing information resulting from a systematic literature review. The overall conclusions of the exercise show that consuming fish provides energy, protein and a range of other nutrients important for health, and that there are benefits related to fish consumption during all life stages (pregnancy, childhood and adulthood). General population studies show that the benefits and individual effects of fish consumption vary depending on overall diet (for instance, selenium intake and exposure to contaminants), the characteristics of consumers (such as long-chain n-3 polyunsaturated fatty acid [n3 LCPUFA] status and individual susceptibility), and the fish that is consumed (including fish species and food preparation methods). Regarding the risks, the data on dietary exposure to dioxins and dioxin-like polychlorinated biphenyls (dl-PCBs) from different foods of animal origin, including fish, indicate that there is consistent evidence for an association between dioxin exposure and reduced semen quality. They further indicate that exposure to total dioxins and dl-PCBs has been associated with altered sex ratio and weaker tooth enamel. In children, there is also an association between dioxin and dl-PCB exposure with body mass index (BMI) z-scores, and increased thyroid stimulating hormone (TSH) with prenatal high-level exposures. In adults, there was some evidence for associations of high exposure to dioxins with cancer, cardiovascular effects and diabetes. In addition, the data analysed indicate that maternal fish consumption during pregnancy is associated with improved offspring neurological development, despite evidence from some populations showing that methylmercury (MeHg) exposure from fish consumption in early life (prenatal and early childhood) has been associated with less neurodevelopmental benefit expected from fish consumption. There is limited evidence of adverse health effects from MeHg exposure in relation to cardiovascular, neurological and other health outcomes in adulthood. There is heterogeneous evidence regarding associations of childhood MeHg exposure with neurological outcomes, possibly reflecting differences in study populations, including selenium (Se) status. Based on physiological mechanisms and evidence from animal studies, MeHg health effects will vary according to Se status and intake; however, evidence from human studies in this regard was limited.