Tuna fish is an excellent source of many nutrients such as protein, selenium, Vitamin B1 (thiamin), Vitamin B3 (niacin), Vitamin B6 (pyridoxine), phosphorus, potassium, magnesium and Omega-3 essential fatty acids.
These last ones are very important, because the human body does not produce them, so we have to take them from external sources. Omega-3 fatty acids are beneficial for the health of the cardiovascular system, by preventing a series of conditions such as high blood pressure, arrhythmias, atrial fibrillation, stroke, heart attacks, or embolisms.
Beware though when cooking for children, as tuna fish contains mercury, which is a toxin that can have a negative influence on children’s health. This is an article that gives more details and shows how to calculate how much mercury is ingested when eating tuna-based meals. This concerns only children, adults not being affected by the mercury levels found in tuna fish.