Ocean Acidification, Iodine Bioavailability, and Cardiovascular Health: A Review of Possible Emerging Risks

Anthropogenic climate change drives ocean acidification, which alters marine iodine cycling and increases bioaccumulation in marine ecosystems. This environmental shift may alter marine iodine cycling and, under certain conditions, lead to increased dietary and atmospheric iodine exposure, particularly in coastal populations, with potential risks for thyroid dysfunction and downstream cardiovascular complications. Experimental data suggest that acidification may enhance iodine uptake in marine organisms such as kelp and seafood, with possible implications for consumption by humans. Because chronic iodine excess has already been associated with thyroid disease and its related cardiovascular disorders, these connections are worthy of further examination. In this narrative review we provide a synthesis of the possible mechanistic pathways by which ocean acidification, iodine bioavailability, thyroid function, and cardiovascular health may be connected. We also highlight the need for ongoing investigation, environmental monitoring, and interdisciplinary collaboration to further explain and address these tentative associations.