China issues deep-sea fish consumption advisory: pregnant women, infants should avoid silverfish, tuna

In response to recent media reports that some infants developed abnormal blood mercury after eating silverfish, and to parents' questions about whether fish is safe and how to eat it for nutrition while avoiding heavy-metal risks, Fang Haiqin, a researcher and director of the Nutrition Division I of the food assessment center, gave an interview to relevant media, and China issued a deep-sea fish consumption advisory. According to media reports, the topic "Hema silverfish mercury poisoning" trended on social media; customer service said frequent consumption is not recommended, and multiple platforms removed products or deleted the child-related wording.

Why does fish warrant attention? The file shows that due to accumulation effects in the food chain, aquatic products, especially deep-sea fish, are prone to mercury contamination from the environment, and organic mercury (mainly methylmercury) poses greater health hazards; large predatory fish at the top of the food chain (such as sharks, swordfish, tuna and silverfish) usually have higher methylmercury levels, while small fish, freshwater fish and farmed fish usually have lower levels. It should be noted that the advisory is general consumption guidance, not a testing conclusion for a specific batch of products.

For infants as a special group, the advisory gives a clearer benchmark: China's total mercury limit for canned complementary foods for infants is 0.02mg/kg, far below the mercury limits for ordinary aquatic products (0.5-1.7mg/kg). It recommends that consumers can obtain nutritional benefits by eating low-mercury fish such as salmon and mackerel in moderation, should avoid long-term, high-frequency consumption of a single species of large predatory fish, and in particular pregnant and breastfeeding women and infants should try to avoid fish with high mercury levels.

The advisory also stresses that marine fish is a good food source, providing quality protein, trace elements, unsaturated fatty acids and other beneficial nutrients, especially rich in essential n-3 polyunsaturated fatty acids, which are needed for fetal brain and retinal development and can reduce the risk of cardiovascular disease in adults; eating marine fish in moderation is beneficial to health. Whichever fish is chosen, it is best not to eat raw or undercooked fish to guard against microbial and parasitic risks.

On how parents should choose products, the advisory specially reminds them to carefully read product labels when purchasing infant foods, take the infant's age into account, and choose compliant products suited to infants' physiological characteristics and special needs for scientific feeding; besides low-mercury fish, parents can also choose dedicated infant complementary foods, which are special dietary foods designed for the physiological development characteristics of infants aged 6 to 36 months, for which China enforces stricter mandatory standards on contaminant limits, raw material requirements and nutritional indicators.