Is It Safe to Eat Tuna Every Day? A Dietitian Explains

"A can of tuna packed in oil contains nearly 200 calories, while a can of tuna packed in water has about half that amount, with approximately 100 calories. Canned tuna is also available in olive oil, which is a much better option than tuna packed in vegetable oil, a vague term that doesn't tell us which oil is being used or its quality," said Dr. Maya Rosman on her radio program. According to Rosman, most canned tuna products contain no preservatives at all.

"A can of tuna contains approximately 30 mg of magnesium, representing about 8% of the recommended daily intake," Rosman added. "It also provides around 2–3 micrograms of vitamin B12, which is enough to meet the body's entire daily requirement."

Is It Safe to Eat Tuna Every Day?

When asked whether it is safe to eat a can of tuna every day, Rosman says: "For most healthy adults, eating one can a day is generally fine. However, as a regular habit, the recommendation is to limit consumption to two or three times a week. This is because tuna does contain small amounts of mercury. Although the amount is relatively low, the recommendation of two to three servings per week includes a safety margin designed to minimize long-term exposure."

"Another important reason is that it's better to vary your sources of protein by including other types of fish, eggs, legumes, and dairy products," she explained.

Canned vs. Fresh Tuna: Which Contains Less Mercury?

Rosman concluded by noting that canned tuna is generally preferable to fresh tuna when it comes to mercury exposure.

"Most canned tuna is made from smaller species of tuna, which tend to have relatively low mercury levels. Fresh tuna, on the other hand, often comes from larger species, which may contain higher concentrations of mercury and pose a greater risk of exposure," the dietitian explained.