Comprehensive review on in vitro bioaccessibility of mercury in various foodstuffs

Accurate assessment of dietary mercury (Hg) exposure and effective risk mitigation rely on a thorough understanding of its bioaccessibility. However, current knowledge of Hg bioaccessibility remains fragmented, with individual studies focusing on specific food types and influencing factors. This hinders the development of comprehensive strategies to achieve Hg exposure-related Sustainable Development Goals. To address this knowledge gap, we conducted a comprehensive review of the bioaccessibility of total Hg (THg) and methylmercury (MeHg) across various foodstuffs. Our analysis included 633 records from 58 studies, covering globally reported seafood and region-specific traditional medicines and rice. We delved into the effects of food components and cooking methods on Hg bioaccessibility and identified the limitations of current research in this area. Our review reveals significant variations in Hg bioaccessibility across foodstuffs, with values ranging from undetectable to 105 % for seafood. Globally, applying bioaccessibility corrections lowers estimates of dietary exposure to THg and MeHg from seafood by 20.6 %-70.9 % and 16.3 %-87.0 %, respectively. Analysis of affecting factors suggests that food components play a crucial role in shaping Hg bioaccessibility through processes such as complexation (including chelation) and sequestration, while high-temperature cooking lowers MeHg bioaccessibility by affecting MeHg-protein complexes. These findings suggest the potential of Hg bioaccessibility-manipulating strategies like co-digestion of foodstuffs rich in phytochemicals and high-temperature cooking to mitigate dietary Hg exposure. Future research should focus on addressing the uncertainty in extrapolating laboratory findings to real-world scenarios to further refine risk assessment and develop effective mitigation strategies.