It is generally safe to eat tuna every day for most people if balanced with other protein sources and not in excessive amounts. Tuna is nutritious, providing protein, essential vitamins, minerals, and omega-3 fatty acids. However, concerns mainly revolve around mercury content, which can accumulate in the body over time. For most adults, eating canned tuna daily in moderate amounts is unlikely to cause harm, as levels of mercury are typically low and regulated. People who are pregnant, trying to conceive, or breastfeeding are usually advised to limit intake to about four cans of tuna or two portions of fresh tuna per week to reduce mercury exposure. Eating tuna daily but varying types and ensuring a varied diet with other proteins like beef, eggs, beans, and nuts is ideal to cover all nutritional needs and avoid potential mercury buildup. Mercury poisoning symptoms from excessive consumption can include memory issues, tremors, and other neurological problems, but these are uncommon with reasonable tuna consumption. In summary, daily tuna consumption can be part of a healthy diet for most people, but moderation and variety are key, especially for sensitive groups like pregnant or breastfeeding women.