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 elevates dietary and atmospheric iodine exposure, particularly in coastal populations, posing risks for thyroid dysfunction and downstream cardiovascular complications. Acidification enhances iodine uptake in marine species, such as kelp and seafood, thereby amplifying human intake. Chronic iodine excess can induce hypothyroidism or hyperthyroidism, both linked to cardiovascular diseases, including heart failure, atrial fibrillation, and atherosclerosis. This narrative review synthesizes the mechanistic pathways connecting ocean acidification, iodine bioavailability, thyroid dysfunction, and cardiovascular health. We emphasize the need for proactive clinical screening, di-etary interventions, environmental monitoring, international collaboration, and inter-disciplinary research to address this climate-sensitive public health challenge. Coastal communities, reliant on marine diets, require targeted strategies to mitigate these emerging risks.