Can daily canned tuna harm your health? Experts weigh the mercury risk
Australian health experts say that eating tinned tuna regularly is unlikely to exceed safe mercury limits for most people.
Canned tuna remains a popular, inexpensive source of protein in Australian lunchboxes, but concerns focus on mercury exposure. Mercury enters the marine food chain as methylmercury, accumulating more in larger, longer-lived fish; however, most Australian tinned tuna is derived from smaller species like skipjack and yellowfin, which hold far less of the toxin. Food Standards Australia New Zealand sets a provisional tolerable weekly intake of 3.3 µg per kilogram of body weight for adults and about half that for pregnant women, translating to roughly 231 µg per one outlet for a 70-kg adult.
A 2025 Spanish analysis found an average of 0.138 mg/kg mercury in canned tuna, meaning a 95-g can contains about 13 µg. Consuming one can daily would still represent only about 40 % of the adult weekly limit and far less for children, whose allowances are lower. Symptoms of mercury poisoning require far higher, prolonged exposure and are not expected from typical Australian diets. While tuna is safe, experts advise varying protein sources to ensure a balanced intake of nutrients.
Why it matters
Understanding tuna's mercury levels helps consumers make safe, nutritious food choices.
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