When you think about healthy food, canned tuna is unlikely to come to your mind. Unfortunately, this fish has gained a bad reputation in recent years. Despite the health benefits and the absence of harm, tuna is at best considered a convenient and quick option for dinner, and not a staple food.
However, tuna is on par with other healthy types of fish, such as salmon and trout, when it comes to nutrition. Tuna has a low calorie count, but a lot of protein and healthy omega-3 fatty acids . It is also filled with antioxidants and important microelements, which makes this fish a worthy food in order to become a regular part of your diet.
What is tuna? Types of Tuna
Tuna is a type of salted fish belonging to the same family as mackerel and bonito fish, i.e. mackerel (Scombridae). It belongs to a group of marine fish called the Tunnini tribe, which includes 15 different species of tuna. The most common types of tuna:
- Atlantic tuna
- Yellowfin tuna
- Common tuna
- Long fin tuna
- Pacific bluefin tuna
- Striped Tuna (Common Skipjack)
The size of the tuna can vary significantly from species to species – for example, yellowfin tuna tuna can weigh about 13 kg. while larger varieties, such as Pacific bluefin tuna, can weigh up to 450 kg.
Tuna stands out among other fish species because it is incredibly fast and able to maintain body temperature above ambient temperature. Some types, such as yellowfin tuna, even tend to swim alongside dolphins in the Pacific Ocean to protect them from predators such as sharks.
Tuna meat is often sold frozen, fresh or canned and is widely consumed worldwide as a popular ingredient for sandwiches, salads, soups.
Nutrition value of tuna and its nutrients
The nutritional profile of tuna may vary slightly depending on the type of tuna, as well as how it is cooked. For example, canned tuna has more calories in oil compared to calories in canned tuna in water. Non-canned tuna contains much less sodium than canned tuna. In general, any tuna has a low calorie count but is rich in protein, selenium, niacin and vitamin B12.
A standard can of canned tuna (170 grams) contains approximately:
Calories : 191 kcal
Proteins : 42.1 gr.
Fats : 1.4 gr.
Selenium : 133 mcg (190%)
Niacin : 21.9 mg (110%)
Vitamin B12 : 4.9 mcg (82%)
Vitamin B6 : 0.6 mg (29%)
Phosphorus : 269 mg (27%)
Sodium : 558 mg (23%)
Iron : 2.5 mg (14%)
Magnesium : 44.6 mg (11%)
Potassium : 391 mg (11%)
Zinc : 1.3 mg (8%)
Riboflavin : 0.1 mg (7%)
In addition to the nutrients listed above, tuna also contains a certain amount of thiamine, vitamin E, pantothenic acid and copper.
The benefits of tuna for the body
Tuna has several proven health benefits to humans. Among them: a high level of protein, assistance in weight loss, contributes to the health of the thyroid gland, enhances brain function, is rich in antioxidants, and reduces inflammation. Consider each of these benefits in more detail.
1. Tuna contains a lot of protein
Protein is essential for many aspects of health. It forms the basis of the cells of the human body – hair, skin, nails and muscles. Protein is crucial for the synthesis of certain enzymes and hormones and is used to grow and repair tissues. Protein deficiency can have detrimental health effects, leading to symptoms such as weakened immunity, slow wound healing, low energy levels, and increased appetite.
Tuna fish is literally loaded with protein: 42 grams of protein per 100 grams of product. Combined with several other high-protein foods, including even one serving of tuna in your diet per day, you can help your body with the protein you need.
2. Tuna – a dietary product
Tuna contains a lot of protein, but few calories, which makes it a great addition to a diet for weight loss. Due to its high protein content, in particular, tuna can help reduce appetite, distract from cravings for sweets and provide a feeling of satiety for a longer time.
A study published in the American Journal of Clinical Nutrition noted that eating high-protein foods leads to a greater decrease in levels of ghrelin, the hormone responsible for stimulating hunger than foods high in carbohydrates. It also slowed down the emptying of the stomach, leading to an increase in satiety ( 1 ). Another study at the University of Washington School of Medicine showed that an increase in protein intake of 15% reduced daily calorie intake by 441 calories and resulted in a significant reduction in body weight and fat mass ( 2 ).
3. Eating tuna contributes to thyroid health
Your thyroid gland is a butterfly-shaped organ located in the neck. The gland is responsible for regulating metabolism, producing hormones and maintaining energy and strength levels. Impaired thyroid function can cause serious symptoms, such as changes in weight, body temperature, bowel habits, sexual function, and concentration.
Tuna is rich in selenium, a mineral that, like iodine, plays a central role in thyroid health. In fact, the thyroid gland is considered the organ with the highest amount of selenium per gram of tissue. Numerous studies have shown that supplementation with selenium may be beneficial for conditions such as autoimmune thyroiditis, Graves disease, and hypothyroidism ( 3 ).
4. Tuna improves brain function
It’s no secret that what you eat can directly affect several aspects of health. However, in recent years, more and more growing evidence has begun to demonstrate how important your diet is when it comes to brain health.
Tuna contains several nutrients that are directly related to brain health. Niacin, in particular, is associated with a lower risk of Alzheimer’s disease and age-related brain changes. Tuna also contains a lot of omega-3 fatty acids, which can enhance cognitive performance and protect against mental health problems such as depression.
5. There are a lot of antioxidants in tuna
Antioxidants are compounds that can help neutralize harmful free radicals to protect against cell damage and chronic diseases. It is believed that eating foods rich in antioxidants prevents the development of diseases such as heart disease, diabetes, cancer and some autoimmune disorders.
Tuna is rich in antioxidant selenium, providing 190% of the daily recommended value for selenium in each jar per 170 grams. Selenium has antioxidant properties and can help reduce oxidative stress and prevent cell damage. According to a study published in the World Journal of Biological Chemistry , tuna is also high in a selenium-containing compound called selenonin, which fights free radicals and can even protect against chronic diseases and aging ( 4 ).
6. Tuna has anti-inflammatory properties
Inflammation is the normal response of the immune system, which helps fight harmful microorganisms and viruses and protects the body from diseases and infections. Prolonged inflammation, on the other hand, is actually an increased risk of developing certain diseases, such as cancer and heart disease.
Tuna is rich in omega-3 fatty acids or fish oil, which can alleviate inflammation and reduce the risk of illness. One of the main distinctive healing properties of omega-3 fatty acids (including tuna) that benefit the human body is their strong anti-inflammatory properties. Numerous studies have shown that they can have a therapeutic effect for autoimmune conditions such as Crohn’s disease, lupus, rheumatoid arthritis, and psoriasis ( 5 ).
Potential harm to tuna
Despite the great benefits, tuna can also be harmful to the body under certain conditions, which should also be taken into account when eating it.
As with any fish species, the mercury content of tuna must be considered. Mercury poisoning can cause symptoms such as memory problems, numbness, tremors, and blurred vision. Some types of tuna accumulate more mercury in themselves than others. For example, canned white tuna (or long fin tuna) contains almost three times more mercury and, accordingly, harm than striped tuna, which can usually be found in canned form ( 6 ).
Children and pregnant women are advised to limit their fish intake to approximately 350 grams per week and avoid high-mercury fish such as king mackerel, big-eyed tuna, clams and swordfish to prevent adverse health effects ( 7 ).
If you order sushi or tuna rolls, please note that this is not Atlantic bluefin tuna. This is due to an important environmental factor. Atlantic bluefin tuna is on the list of fish that are on the verge of extinction because it is used by people for commercial purposes on a large scale. However, since it is in good demand, this type of tuna is still an object of commercial fishing, and therefore its population, unfortunately, continues to decline.
In addition to the environmental impacts associated with Atlantic bluefin tuna, this type of tuna also has a high mercury content and is therefore best avoided.
Atlantic bluefin tuna is also often farmed, which can be even worse and more harmful than consuming bacon for your body. It has been proven that some fish species grown on farms contain a higher concentration of toxins and chemicals that can be harmful to health, such as dioxins and pesticides ( 8 ). Therefore, instead of eating these, it is better to choose other types of tuna, such as striped tuna, which are rarely bred on farms, and most often fishermen catch sea trolling.
If you eat canned tuna, you should also consider its sodium content. Like most canned foods, canned tuna usually has a high sodium content, which can be harmful to the heart and hypertensives (sodium increases pressure). Better to choose tuna in water or natural juice, but not in oil or other sauce – this is the best canned tuna if you want to reduce sodium intake. Before use, it is also recommended to rinse canned tuna with drinking water – this can also reduce the sodium content to 80% and will not be so harmful ( 9 ).
Possible risks and precautions for eating tuna
If you are allergic to fish, you should avoid eating tuna, as well as other types of seafood. In addition, if you experience symptoms of a food allergy after eating tuna, stop eating it and consult a doctor.
Look for low-mercury tuna for your diet and avoid high-alloyed fish such as bluefin tuna and big-eyed tuna. Children and pregnant women should maintain moderate amounts of fish in order to minimize the harmful effects of mercury.
You should also avoid eating Atlantic bluefin tuna, because it can cause negative consequences for both the environment and your body, since in the natural environment this species is on the verge of extinction and therefore it is often grown on farms, where it is often infected with toxins and pesticides.
Tuna or salmon – which is better
Tuna and salmon can be considered two of the most commonly used fish species, but there are many differences that distinguish them.
Tuna has a softer, less fishy taste, while salmon is usually fatter, juicy and tender. Both types of fish can be prepared in a similar way and are available fresh and canned.
If you compare the nutrient profile of boiled salmon and tuna per 100 grams, then tuna will have more protein and fewer calories. It also contains more certain micronutrients such as niacin, phosphorus and vitamin B12. Salmon, on the other hand, has more folic acid and healthy fats, including omega-3 fatty acids.
At the same time, both types of fish are easy to find in the market or in the store. Both tuna and salmon will benefit the body, fill with nutrients and become a valuable addition to a balanced meal. Both salmon and tuna are recommended to be consumed no more than once a week in order to maximize benefits and minimize possible harm to the body.
Canned Tuna or Fresh
Tuna is widely available at most grocery stores and supermarkets. Canned tuna is available in almost any supermarket on the planet. Usually he is in the same place as other canned fish, such as salmon and sardines.
However, in addition to canned tuna, there are other types of tuna. You can also often find frozen tuna steaks at most grocery stores, or you can find it fresh at farmers markets or specialty fish stores.
The price of tuna may vary depending on the type of tuna you are buying. Canned tuna is usually the most affordable option, while fresh bluefin tuna is one of the most expensive.
So, we examined questions about the benefits and harms of tuna for the body. To summarize:
- Tuna is a type of marine fish belonging to the same family as mackerel and bonito fish. The weight of tuna can vary widely: from 20 to 500 kilograms, depending on the type of fish.
- Tuna is low in calories, but high in protein, niacin, selenium and vitamin B12.
- Adding tuna to your diet can improve your weight loss process, reduce inflammation, increase brain function, and enhance thyroid health.
- Some types of tuna contain excessive amounts of mercury, are on the verge of extinction and are often farmed – these species are not recommended for inclusion in your diet. For these reasons, you should avoid eating Atlantic bluefin tuna and choose healthier varieties such as striped tuna.