Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. 
Divine Aleru is an accomplished biochemist and researcher with a specialized background in environmental toxicology, focusing on the impacts of heavy metals on human health. With deep-rooted expertise in microbiome signatures analysis, Divine seamlessly blends rigorous scientific training with her passion for deciphering the intricate relationships between environmental exposures and the human microbiome. Her career is distinguished by a commitment to advancing integrative health interventions, leveraging cutting-edge microbiome research to illuminate how toxic metals shape biological systems. Driven by curiosity and innovation, Divine is dedicated to translating complex environmental findings into actionable insights that improve individual and public health outcomes. What was reviewed?
This review examined the health benefits and risks of consuming contaminated fish, with a focus on how nutrients and pollutants influence real-world diet advice and control plans for supply chains. The authors showed how omega-3s, protein, vitamin D, iodine, and selenium support heart and brain health, yet contaminants can erode those gains when levels rise in key species. They traced methylmercury from microbial methylation to fish tissue, then to people who eat large predatory fish, and linked blood and hair markers to risk. Work on PCBs, dioxins, pesticides, and microplastics added non-metal hazards that can travel with the seafood trade. The review tied mechanisms such as thiol binding, redox stress, and calcium shifts to nerve injury, growth limits, and early vascular change that matter for fetal life and for adults with high intake.
Who was reviewed?
Evidence covered high fish eaters in coastal regions, mothers and infants in pregnancy and lactation cohorts, and workers who handle fish or live near polluted waters. Studies followed adults and children in Asia, Africa, the Americas, and Europe to capture wide habits and price limits that steer species choice. Clinic and community cohorts linked maternal biomarkers to birth size, child neuro scores, and early blood pressure. Work on adults looked at vision speed, fine motor skill, and signs of vascular strain across a range of intake. Several data sets tracked species that carry more methylmercury, such as shark, swordfish, king mackerel, and some tuna, and set them against lower-mercury choices like salmon, sardine, tilapia, cod, trout, and catfish. Results tied real foods, real markets, and real life stages to clear exposure paths that programs can monitor.
Most important findings
Nutrients in fish support heart, brain, and immune health, yet methylmercury often sets the exposure ceiling because it rises with trophic level and fish size. Cohorts that ate more large predatory fish showed higher hair or blood mercury and more frequent signs of neuro or cardio stress, while groups that chose small pelagics or farmed salmon showed lower biomarkers and fewer effects. Pregnancy studies connected first or second trimester mercury to lower birth weight and, in some settings, shorter length or smaller placentas. Child cohorts with higher prenatal or early-life mercury showed small but real drops in language, memory, or motor scores. Adult cohorts linked higher mercury with higher blood pressure and weaker heart benefits from fish, which suggests a toxic-nutrient tradeoff at high exposures.
Mechanistic work supported those links by showing glutathione loss, superoxide rise, microtubule damage, and impaired nitric-oxide signaling in vessels and brain. PCBs and dioxins added cancer and immune risks and rose with fat content and age of fish, while pesticide data showed oxidative stress and endocrine effects in exposed groups. Microplastics emerged as a new vector that can carry metals and organics and may add gut and immune stress, yet metals still dominate risk setting for seafood buyers and certifiers. Together, the findings argue for species-aware purchase rules, portion targets that fit pregnancy and early life, and routine tests that catch high lots before sale.
Key implications
HTMC can align claims with science by setting speciation-aware limits, clear species tiers, and simple, repeatable tests. Buyers can favor low-mercury species for general use and reserve high-trophic species for rare, controlled sale with tighter action levels. Quality teams can test total mercury on a wet-weight basis with accredited labs and trend results by species, size class, and origin. Programs can add hair or blood tracking in at-risk crews and include a basic redox panel in high-exposure settings to spot early change. Labels can steer pregnant people and young children toward low-mercury choices and set plain portion advice. Audits can verify species IDs, catch area, and size data because those fields predict mercury best and drive real exposure outcomes. These steps cut dose without losing the core health gains that fish can bring.
Citation
Demelash Abera, B., & Alefe Adimas, M. (2024). Health benefits and health risks of contaminated fish consumption: Current research outputs, research approaches, and perspectives. Heliyon, 10(13), e33905. https://doi.org/10.1016/j.heliyon.2024.e33905
