The safe amount of canned tuna to eat per week varies depending on the type of tuna and individual factors such as age, pregnancy status, and sensitivity to mercury. Adults can generally safely consume 6 to 12 ounces (170 to 340 grams) of canned light tuna per week, which is considered low in mercury. This typically equals about 1 to 3 servings or 1 to 3 cans of standard-sized tuna. Pregnant or breastfeeding women are advised to limit canned light tuna to 2 to 3 servings per week. For canned albacore (white) tuna, which has higher mercury levels, the recommendation is lower: about one serving per week for pregnant or breastfeeding women, and for children, smaller portions are recommended based on age. Children can safely consume around 2 servings of canned light tuna per week. It is also recommended to diversify protein sources and consider the size and source of the tuna, as smaller fish like skipjack (used in light tuna) contain less mercury than larger types like albacore or yellowfin.

In summary:

• Canned light tuna: Up to 12 oz (around 3 cans) per week for adults, 2-3 servings for pregnant/breastfeeding women.
• Canned albacore tuna: Around 6 oz (1-2 cans) per week max, especially limited for sensitive groups.
• Children should eat smaller portions scaled by age.

Choosing tuna labeled as "light," "skipjack," or sustainably caught can help reduce mercury exposure risks.