The health benefits of tuna fish include its ability to reduce cardiovascular disorders, stimulate growth and development, lower blood pressure and cholesterol levels, and help in weight loss. Tuna also has the ability to boost the immune system, increase energy, aid in skin care, increase red blood cell count, and has anti-cancer properties. It also protects against various kidney diseases, prevents age-related macular degeneration, reduces general inflammation, and inhibits cell membrane damage.
What is Tuna Fish?
Tuna fish is a very diverse saltwater fish that belongs to the Scombridae family, commonly called the mackerel group.  Within this family, tuna benefits belong to a tribe, called Thunnini. This tribe contains 15 species of tuna, several of which are enjoyed around the world in culinary traditions.
This variety of fish are typically anywhere from 1 foot in length to 15 feet for a fully grown, long-lived example. While most of these fish live for 3-5 years, some have been known to live for more than two decades. They regularly make long migration across the oceans, sometimes thousands of miles in length, due to mating and changing seasons.
Nutritional Value of Tuna Fish
The health benefits of tuna fish can be attributed to the impressive content of vitamins, minerals, and organic compounds found in this delicious fish.  These include antioxidants and protein, without much-saturated fat or sodium. It also has impressive levels of selenium, phosphorus, iron, magnesium, and potassium, according to the USDA National Nutrient Database.
Perhaps the most common health benefit that is attributed to tuna fish is its significant impact on heart health.  In terms of reducing coronary heart diseases, this fish has high levels of omega-3 fatty acids, which help reduce omega-6 fatty acids and LDL or bad cholesterol in the arteries and blood vessels. Furthermore, it often replaces foods with high saturated fat content, further lowering the risk of heart diseases. According to a study published in the Journal of the American Medical Association , women who consumed higher amounts of fish, including tuna, and omega-3 fatty acids have a lower risk of coronary heart disease.
Tuna fish, being rich in omega-3 fatty acids, is a great option for preventing eye disorders like age-related macular degeneration. Paul A. Sieving, M.D., Ph.D., director of the National Eye Institute (NEI), and John Paul SanGiovanni, Sc.D., were involved in a comprehensive research study on dietary omega-3 fatty acids in protecting against the development and progression of retinal disease.  This disease is the major reason behind the occurrence of blindness in elderly people. The blindness is also caused due to diabetic complications and this fish can help in reducing the chances of diabetic retinopathy.
Boosted Immune System
Tuna contains a good amount of vitamin C, zinc, and manganese, all of which are considered antioxidant in nature. Antioxidants are one of the body’s defense mechanisms against free radicals, the harmful by-products of cellular metabolism that cause chronic diseases.  However, the real champion of tuna’s immune system-boosting potential is selenium.  This fish is rich in this mineral, giving nearly 200% of the daily requirement in a single serving. This makes the fish a very powerful antioxidant and immune-boosting food.
Tuna fish has antioxidant properties, thanks to selenium and other nutrients, making it effective at preventing some types of cancer. In the American Association for Cancer Research, a study titled “A 22-year Prospective Study of Fish, n-3 Fatty Acid Intake, and Colorectal Cancer Risk in Men” suggested that fish consumption, especially the fatty fish variety, may decrease the risk for colorectal cancer.
The potassium and sodium content in tuna is well-balanced, meaning it is high in potassium and low in sodium.  This helps manage the fluid balance in the body. When your body maintains a fluid balance, the kidneys function properly, thereby lowering the chances of developing serious kidney conditions. However, for individuals with chronic kidney disease, be sure and speak with your doctor or dietitian before adding tuna or making any major alterations to your diet. Tuna contains both potassium and phosphorus which can build up and become toxic in people who have damaged kidneys.