Tuna Fish – Nutritional Value, Health Benefits, Recipes

A tuna fish is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprises 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna (max. length: 50 cm (1.6 ft), weight: 1.8 kg (4 lb)) up to the Atlantic bluefin tuna (max. length: 4.6 m (15 ft), weight: 684 kg (1,508 lb)). The Atlantic bluefin averages 2 m (6.6 ft), and is believed to live up to 50 years.

Tuna, opah, and mackerel sharks are the only species of fish that can maintain a body temperature higher than that of the surrounding water. An active and agile predator, the tuna has a sleek, streamlined body, and is among the fastest-swimming pelagic fish – the yellowfin tuna, for example, is capable of speeds of up to 75 km/h (47 mph).^[rx][rx] Greatly inflated speeds can be found in early scientific reports and are still widely reported in the popular literature.^[rx] Found in warm seas, it is extensively fished commercially and is popular as a game fish. As a result of overfishing, some tuna species, such as the southern bluefin tuna, are threatened with extinction.^[rx]

 

Tuna is a saltwater fish that belongs to genus Thunnus in the mackerel family (Scombridae) which also includes the bonitos, albacore and mackerels. However, tuna belong to a tribe, called Thunnini. This “tribe” consists of 15 species of tuna, most of which are appreciated around the world in some sort of culinary tradition. The fish are distributed throughout the world from tropical to temperate oceans of the Atlantic, Pacific and Indian. Their delicious taste, global availability, and healthy components make it an ideal replacement for red meat or for those who like to add some healthy variety to their diets. Japan is the highest consumer of fresh tuna, while US is highest consumer of canned tuna. Other common species of tuna are bluefin, ahi, albacore and big eye. Japan, Indonesia and Philippines are the top tuna catchers. The taste of tuna fish makes it perfect for eating as a tuna steak, in “burger” form, as a spread with mayonnaise on crackers or bread, in tuna salad, or any number of other varieties. It is versatile, delicious, inexpensive, and very good for you.

 

Physical Appearance

Tunas are elongated, robust, sleek and streamlined fishes; they have a rounded body that tapers to a slender tail base and a forked or crescent-shaped tail. In color, tunas are generally dark above and silvery below, often with an iridescent shine. They have a conspicuous keel on either side of the tail base; a row of small fin lets behind dorsal and anal fins, and a corselet of enlarged scales in the shoulder region. Another notable feature is a well-developed network of blood vessels below the skin that acts as a temperature-regulating device associated with long-term, slow swimming.

However this appearance varies amongst the different types of tuna fish. The Yellow fin tuna, as its name implies, is more yellow than the other species. There is a golden stripe that runs along the side of the Yellow fin. The second dorsal and anal fins and fin lets are also bright yellow. Skipjack tuna, on the other hand, dark purple-blue backs while their lower sides and bellies are silver with four to six dark bands.

History

Tuna has been fished by Pacific peoples for millennia. In the Mediterranean, Tuna has been a part of their diet since the Greeks and Romans. Not much Tuna was eaten by the English-speaking world, however, prior to the 1910s. Fishing for albacore Tuna to be sold fresh began off the coast of southern California in the late 1800s.

Tuna really became available, however, with the advent of canned Tuna. Canning turned out to be a perfect way of preserving Tuna and to reach inland markets. A Tuna canning factory was established in Olhão, Portugal in 1882. By the 1880s, the US was importing canned Tuna from France. In 1903, a trial of canned albacore in California proved successful and the American canned Tuna industry took off. Demand led to the canning of skipjack, blue fin and yellow fin in America by the 1920s.

 

Tuna Types

Tuna is not a single species of fish, but rather numerous species.  Scientists often use the term “tuna and tuna-like fish” which includes a total of 61 species, fourteen of which are considered “true tuna”. Four species are of major commercial importance in the Pacific Islands: skipjack, yellowfin, big eye, and albacore. Listed below are some of the popular varieties of Tuna fish

1. Bluefin Tuna

Bluefin Tuna is normally found in subtropical and temperate waters of the Atlantic and North Pacific Oceans, also in the Mediterranean and Black Seas. Its high-quality meat commands a premium price in the “sashimi” market in Japan.

2. Southern Bluefin Tuna

Southern Bluefin Tuna has an excellent sweetness so it is popular for sushi, they look similar to bluefin tuna but they are smaller and the size is only 2.2 m in length and 160 kg in weight. Its main characteristic is the small yellowfin near their tails. Its meat consists of rich amounts of iron and because of the red color, it’s easy to see the border between the red meat and the fatty part (Toro). The Toro part of the fish is thick and very sweet, plus it’s nice and fatty so it is used as much as bluefin tuna as a premium tuna in sushi shops.

3. Big eye Tuna

Blue eye tuna has a lot of distribution in the Kanto region, East Japan, and surrounding areas, that deliver sushi, sushi train restaurants, and supermarkets have big eye tuna mostly. The meat has less fat compared to bluefin tuna and southern bluefin tuna so it’s No.3 when it comes to sushi and sashimi. The taste is light, but both red meat and middle-fat are delicious too so there are numerous dishes that can be enjoyed such as carpaccio, pickles, wood fried, and simmered dishes with eyeballs. Big eye tuna from the Sanriku region in coastal Japan is extremely valued as sashimi, particularly in autumn.

4. Yellowfin Tuna

Yellowfin tuna is liked in the Kansai region, West Japan. The meat is a light red color close to pink and the taste is light with no sharpness. The fat is low so the Toro part cannot be taken out but the meat is firm, so it’s perfect for sashimi or steak. It’s called Ahi in Hawaii, and it’s popular. The season is from spring to summer and this yellowfin tuna caught in Japanese coastal areas has a high reputation as sashimi too. Also, they are used for tinned tuna products a lot.

5. Albacore

Albacore tuna is often consumed as processed products; it’s an extensively famous ingredient for tinned tuna. Pale pink and almost white-colored meat has a chicken-like texture more than tuna. They are loved in Europe and the US, and there are global demands. The size is 140 cm long and 60 kg in weight; the pectoral fin is considerably long. They widely inhabit the temperate and tropical zones in the world.

6. Skipjack

Skipjack is a surface–schooling tuna that are simply distinguished from other species of tuna due to their small size, small dark pectoral fins, and three to six distinct dark longitudinal lines (stripes). It is found year-round concentrated in warmer tropical waters of the WCPO, with that distribution expanding seasonally into subtropical waters to the north and south.

7. Bonito

Bonito is a species related to the tuna family, but cannot be promoted as Tuna in many countries.  Bonito is quite popular as a fried fish with olive oil, particularly in the Mediterranean region. Due to its small size and firm dark meat, it is well fit for this purpose. The species is mostly fished in coastal water by small local vessels. The catches tend to be quite seasonal.

8. Little tunny

The little tunny is distinguished by a scattering of dark spots, commonly 4-5, resembling fingerprints between the pectoral and ventral fins. This species also has wavy markings found on the back above the lateral line, located within a well-marked border that never ranges further forward than the middle of the first dorsal fin. The pectoral and ventral fins are short and broad, and the two dorsal fins are separated at the base by a small interspace. The teeth are small and conical. No swim bladder is present. There are 37-43 gill rakers on the first-gill arch.

Proximity	Amount	% DV
Water	50.23 g	N/D
Energy	156 Kcal	N/D
Energy	654 kJ	N/D
Protein	25.42 g	50.84%
Total Fat (lipid)	5.34 g	15.26%
Ash	1.28 g	N/D

Minerals	Amount	% DV
Calcium, Ca	8 mg	0.80%
Iron, Fe	1.11 mg	13.88%
Magnesium, Mg	54 mg	12.86%
Phosphorus, P	277 mg	39.57%
Potassium, K	275 mg	5.85%
Sodium, Na	42 mg	2.80%
Zinc, Zn	0.65 mg	5.91%
Copper, Cu	0.093 mg	10.33%
Manganese, Mn	0.017 mg	0.74%
Selenium, Se	39.8 µg	72.36%

Vitamins	Amount	% DV
Water-soluble Vitamins
Vitamin B1 (Thiamin)	0.236 mg	19.67%
Vitamin B2 (Riboflavin)	0.26 mg	20.00%
Vitamin B3 (Niacin)	8.959 mg	55.99%
Vitamin B5 (Pantothenic acid)	1.165 mg	23.30%
Vitamin B6 (Pyridoxine)	0.446 mg	34.31%
Vitamin B9 (Folate)	2 µg	0.50%
Folate, food	2 µg	N/D
Folate, DEF	2 µg	N/D
Vitamin B-12 (Cobalamine)	9.25 µg	385.42%
Fat-soluble Vitamins
Vitamin A, RAE	643 µg	91.86%
Vitamin A, IU	2142 IU	N/D
Retinol	643 µg	N/D

Lipids	Amount	% DV
Fatty acids, total saturated	1.37 g	N/D
Myristic acid  14:00(Tetradecanoic acid)	0.151 g	N/D
Palmitic acid 16:00 (Hexadecanoic acid)	0.882 g	N/D
Stearic acid 18:00 (Octadecanoic acid)	0.335 g	N/D
Fatty acids, total monounsaturated	1.745 g	N/D
Palmitoleic acid 16:1 (hexadecenoic acid)	0.177 g	N/D
Oleic acid 18:1 (octadecenoic acid)	1.007 g	N/D
Gadoleic acid 20:1 (eicosenoic acid)	0.302 g	N/D
Erucic acid 22:1 (docosenoic acid)	0.258 g	N/D
Fatty acids, total polyunsaturated	1.567 g	N/D
Linoleic acid 18:2 (octadecadienoic acid)	0.058 g	N/D
18:04	0.043 g	N/D
Arachidonic acid 20:4 (Eicosatetraenoic acid)	0.047 g	N/D
20:5 n-3 (EPA)	0.309 g	N/D
22:5 n-3 (DPA)	0.136 g	N/D
22:6 n-3 (DHA)	0.97 g	N/D
Cholesterol	42 mg	N/D

Amino acids	Amount	% DV
Tryptophan	0.285 g	64.77%
Threonine	1.114 g	63.30%
Isoleucine	1.171 g	70.04%
Leucine	2.066 g	55.90%
Lysine	2.335 g	69.83%
Methionine	0.752 g	N/D
Cystine	0.273 g	N/D
Phenylalanine	0.993 g	N/D
Tyrosine	0.858 g	N/D
Valine	1.31 g	62.03%
Arginine	1.522 g	N/D
Histidine	0.748 g	60.71%
Alanine	1.538 g	N/D
Aspartic acid	2.603 g	N/D
Glutamic acid	3.794 g	N/D
Glycine	1.221 g	N/D
Proline	0.898 g	N/D
Serine	1.037 g	N/D

*Above mentioned Percent Daily Values (%DVs) are based on 2,000 calorie diet intake. Daily values (DVs) may be different depending upon your daily calorie needs. Mentioned values are recommended by the U.S. Department of Agriculture. They are not healthbenefitstimes.com recommendations. Calculations are based on average age of 19 to 50 years and weigh 194 lbs. Source: https://ndb.nal.usda.gov/ 

Health Benefits of Tuna Fish

We all know that consuming fish is healthy and that we should eat it at least twice a week. The benefits of eating tuna are many, and tuna is healthy, we should all eat more tuna. Today we’re having a closer look at them, and bring you the benefits of tuna fish in detail. Let’s dive in.

1. Cancer Prevention

As we all know that, tuna fish has very good antioxidant properties thanks to selenium and various other nutritional components, making it effective at preventing some types of cancer. Numerous researches are ongoing, but those already conducted have connected tuna to a reduction in the occurrence of breast cancer, while other studies have also revealed a benefit against kidney cancer as well. Selenium is a powerful antioxidant that neutralizes free radicals before they can cause mutations in healthy cells, thus turning them into cancer cells. Other promising results have shown a reduction in colon cancer, thanks to the high levels of omega-3 fatty acids.(1)

2. Growth and Development

When people give up red meat or become a vegetarian, one of the most dangerous dietary challenges is obtaining an appropriate amount of protein. Fortunately, for pescatarians, tuna fish is loaded with protein. A single serving of only 165 grams (nearly 1 can of tuna fish) consists of more than 80% of your daily protein requirement. Proteins are the building blocks of our body and with proper amounts of protein in our system, we are certain to have increased growth and development, faster recovery from wounds and illnesses, improved muscle tone and growth, and overall metabolic efficiency. It can boost our energy levels and make our body work more efficiently.(2)

3. Blood Circulation

Tuna fish is quite beneficial for the heart as well as for the blood! It is a rich source of iron, along with the B-complex vitamins that play an important role in red blood cell formation. Without iron, people become anemic, and their blood is unable to appropriately oxygenate the body’s extremities or vital organ systems that need fresh oxygen to function proficiently. It provides an important source of iron, keeping our body operating at optimal levels. (3)

4. Kidney Disease

The potassium and sodium content found in tuna is well-balanced, which helps to manage the fluid balance in the body. When your body properly maintains the fluid balance between salts and potassium, then the kidneys can function appropriately and without undue stress, thus lowering the chances of developing and serious kidney conditions.

5. Boosted Immune System

Tuna fish consists of good amounts 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 byproducts of cellular metabolism that can cause cancer and other chronic diseases. However, the real champion of tuna’s immune system-boosting potential is selenium. This relatively rare mineral is found in huge quantities in tuna fish, nearly 200% of the daily requirement in a single serving. This makes tuna fish a very powerful antioxidant and immune system-stimulating food source. (4)

6. Reduce Inflammation

Tuna fish consists of healthy cholesterol and anti-inflammatory vitamins and minerals, which help to keep the body’s overall stress levels down. A reduction in inflammation across the body helps all of the organ systems by not diverting resources away from essential functions. It also helps to prevent inflammatory diseases like arthritis and gout, both of which afflict millions of people around the world.(5)

7. Depression

Frequent consumption of Tuna is a good cure for depression. Research study recommends that fish consumption may be beneficial for women’s mental health and reduce the risk of developing depression in women.(6)

8. Good for eye health

Macular degeneration which causes vision to deteriorate is the main cause of blindness in people over the age of 50. The omega-3 fatty acid present in tuna prevents the occurrence of this condition. Tuna also protects individuals from dry eye syndrome which is a significant ocular complaint.

9. Heart Health

Tuna fish has a significant impact on heart health.  Tuna fish consists of a good amount of omega-3 fatty acids which helps to reduce coronary heart disease and also reduce omega-6 fatty acids and cholesterol in the arteries and blood vessels. Additionally, it often replaces foods with high saturated fat content, further lowering the risk of heart diseases of various types.(7)

10. Strengthens your bones

Vitamin D contained in Tuna fish is the major building component of the bones. The benefits of this vitamin demonstrate in cancer prevention, strong and healthy bones, and no fractures.

11. Energy Levels

B complex of vitamins has been associated with a wide range of health aspects, but as a whole, they are mainly involved in improving the metabolism and increasing the effectiveness of our organ systems, while also protecting the skin and increasing energy. By consuming tuna fish frequently, you can guarantee that you are active, energetic, and healthy.(8)

12. Cell Membrane Damage

Proteins present in tuna fish start to break down into fragments, called peptides when heated, and these fragments can in fact be powerful antioxidants that specifically target cell membranes, keeping them healthy, strong, and functioning properly. Free radicals often attack membranes throughout the body, including those in the brain, so cooking tuna and boosting our membrane protection is a very good idea!(9)

13. Brain Health

Making tuna a part of a regular diet will help prevent cognitive decline and Alzheimer’s disease. This is because omega-3 fatty acid prevents inflammation and encourages blood supply to the brain. Niacin present in tuna also plays an important role in delaying age-related cognitive decline and decreases the likelihood of contracting Alzheimer’s disease.

14. Reduces stress

As we have mentioned before tuna fish is rich in omega-3 fatty acids and helps to reduces stress. A recent study has shown that the relationship between eating tuna-rich in omega-3 fatty acids and decreasing the aggression levels among youngsters is enormous. Other similar studies tell that the DHA will lessen the degree of aggression and improve the ability to deal with stress. Besides all of this, it has been proven that aggressive people have increased omega-3 amounts in the blood plasma.

15. Blood Pressure

The combination of omega-3 fatty acids helps reduce blood pressure, along with potassium, a vasodilator, making tuna fish very good for lowering blood pressure. Reducing hypertension can considerably boost your health by lowering the strain on your cardiovascular system. This will help prevent heart attacks and strokes, as well as conditions like atherosclerosis, which can lead to a number of health complications.(10)

16. Weight Loss and Obesity

Obesity is one of the most distressing conditions that are on the rise in current decades. Thankfully, tuna fish is low in calories and fat, yet overloaded with beneficial nutrients and protein. Additionally, the omega-3 fatty acids found in tuna stimulate a hormone called leptin, which balances the body’s food intake with the internal desire to eat more. This can decrease overeating and make sure that your body is only consuming what it actually needs, assisting to quickly get your diet and appetite back on track.(11)

17. Mercury and Selenium Balance

Many fish consists of small levels of methyl-mercury, and when eaten in small quantities, do not harm humans. However, in larger quantities, mercury poisoning can occur, which is difficult and dangerous. Thus, opposing studies have recommended certain amounts of tuna to be eaten, but that might bring the mercury level to an unhealthy point. The most recent research has shown that there is a unique form of selenium, called selenoneine. This actually binds to mercury and acts as an antioxidant, slightly changing the composition of mercury to make it less dangerous. This has been witnessed occurring in the tuna’s body, but ongoing studies will show if we can receive the same benefits.(12)

18. Improves your skin health

Tuna consists of the trace mineral, which prevents damage to blood cells due to intoxication and health state of the body. Second, a protein called elastin provides additional tissue repairs and gives smoothness to the skin.

19. Fights kidney disease

Potassium mineral present in Tuna helps with the fluid balance and regular functioning of the kidneys. Kidney cancer is one of the most frequent cancer types in the world, and it develops from the inadequate functioning of organs. Including tuna fish in your diet is one of the best options to fight kidney disease.

20. Prevents stroke

With five servings of tuna a week, adults can lower the risk of stroke by 30%. The prevention of blood clots and improving the artery walls, thanks to B vitamin complex and folic acids in tuna.

21. Builds muscle

One of the main ingredients of tuna meat is protein. Tuna is among the protein-richest meats, making it the perfect companion in muscle development and fat loss. Muscles grow from proteins, recover faster, and improve the metabolism rate of the body.

22. Improves your mood

Selenium found in Tuna fish helps to handles the appetite and mood in humans. Research shows that a lack of selenium in the body will cause anxiety. Another benefit of omega-3 acids is the mood improvement process that they trigger.

https://www.youtube.com/watch?v=HzYb1iJRqaw

How to eat

• Tuna is a very popular ingredient in some cuisines.
• Canned tuna is eaten in sandwiches, salads, and pickles in American cuisines.
• Fresh tuna is served as sashimi or used on sushi in Japanese Cuisines.
• It is also popular in coastal regions where the fish is made by frying, grilling, currying, or skewering the fish meat.
• Tuna, either fresh or canned, are rich in protein, vitamins, and omega 3 fatty acids that provide a range of health benefits.
• Canned tuna is served as part of an antipasto plate and is used to make salads, sandwiches, and casseroles.

Other facts

• Yellowfin tuna is capable of speeds of up to 75 km/h (47 mph).
• Tunas are over-fished in different parts of the world, especially in Japan and Australia.
• The largest (ever recorded) specimen of tuna was 21 feet long, weighing 1600 pounds.
• Despite their large size, tunas are very fast swimmers. They can reach the speed between 44 and 62 miles per hour.
• Tuna can swim near the surface or can dive to the depth of 3000 feet while it searches for food.
• Tuna is a carnivore. It feeds on different types of fish (mackerel, herring, hak), squids and crustaceans.
• Tunas can travel large distances in a short period of time. It can pass across the entire Atlantic in 30 days by traveling 16 miles per hour.
• One female can release 30 million eggs. Only 2 of those 30 million will survive until adulthood. The remaining eggs will be eaten by other marine creatures.
• Tuna usually swim at a speed of around 40km per hour.
• To get enough oxygen they must move one body length per second.
• Tuna get their oxygen from water, not from the air.
• A typical tuna may eat one-quarter its own weight in food in one day!
• They can dive to the depth of 3000 feet to search for their next meal.

Selecting

Fresh albacore is generally available from spring through fall, while yellowfin is available year-round but is most abundant in summer. The different kinds of fresh tuna are exchangeable for cooked dishes, although yellowfin steaks are often favored for grilling and pan roasting. For sushi and sashimi, look for the freshest possible fish, usually labeled “sushi-grade,” “sashimi-grade,” “tuna loin” or “tuna belly.”

When selecting canned tuna, imported Italian tuna packed in olive oil is considered the premium kind for antipasto, salads, and sandwiches, though you may prefer a lower-calorie tuna packed in spring water. Domestic tuna is also packed in vegetable oil. Solid albacore tuna is the most expensive domestic canned tuna followed by chunk light tuna and then flaked light tuna. Solid albacore can be somewhat dry, however, and some cooks prefer chunk light tuna. “Dolphin-safe” or “line-caught” tuna has been caught by methods that do not endanger dolphins.

Storing

Pat fresh tuna dry with paper towels and put it in a heavy-duty zippered plastic bag. Place the bag on top of a bowl of ice cubes or cracked ice and refrigerate. Cook the fish the day you buy it. If you must wait, it should be kept no longer than 24 hours. Freezing degrades the texture and flavor of fish somewhat, but if you must freeze tuna, place it in a freezer-weight plastic bag and freeze for up to 1 month. Defrost in the refrigerator. Unopened canned tuna may be kept indefinitely.

Drawbacks

Overall eating fish is a very healthy activity to do. Fish meat has positive oils and is normally quite healthy for your digestive system overall. A few things to consider, however:

Some fish has been liked to have higher levels of mercury in the people who consume it. This typically only happens when the people are consuming it daily and for several meals a day (depending on your consumption you may want to consider it).

From an environmental level, overfishing has become wide-ranging and many tuna stocks have been fished to near extinction. If you are consuming a lot of tuna, and it sounds like you are, you may want to look for brands and are more environmentally conscious to minimize your impact on the environment.

Precautions 

• The consumption of sea fish if one is trying to reduce inflammatory diseases such as heart disease.
• Farmed ones contain arsenic that leads to arsenic poisoning.
• Seafood should be cooked safely in order to prevent foodborne illness.
• Pregnant women, young children, older adults, people having lower stomach acid and compromised immune systems (HIV/AIDS, liver disease, cancer, diabetes, gastrointestinal disorders, people taking steroids, chemotherapy, or immune system) are prone to higher risk.
• It might be contaminated with bacteria such as Vibrio parahaemolyticus, Vibrio vulnificus, and other bacteria relate to land use, sewage discharges, runoff, etc. These microorganisms occur naturally in warm coastal waters which could cause even death or serious illness in individuals who are at higher risk.
• Listeria monocytogenes could cause a serious foodborne illness known as listeriosis.
• The virus Hepatitis A could survive in light cooking. So one should consume it after being properly cooked.
• Fish could have toxins that could cause illness such as ciguatoxin and scombrotoxin, or histamine poisoning.
• Sea fish is related to Scombrotoxin (histamine) which develops when fish is not kept cold enough. The symptoms develop quickly and also disappear completely within 24 hours.
• The flesh of tropical marine fishes might cause ciguatera poisoning experiencing gastrointestinal maladies that could last for several days, weakness in arms and legs, and reversal inability to differentiate between cold and hot. The symptoms could persist for weeks.
• Farmed seafood results in to increase in inflammation leading to weight gain, arthritis, and heart diseases.
• The imbalance ratio of Omega-6 and Omega-3 causes heart disease and hypertension.
• Seafood and fish in farms have polychlorinated biphenyls (PCBs), organophosphorus (OPs), organochlorine (OC), trifluralin pesticides, and hexachlorobenzene (HCB) causing diseases or even death.
• The seafood has a high content of mercury, which may lead to mercury toxicity.
• Consume it in moderate amounts. So consume it with caution or Avoid consuming it raw.
• Some people might get allergic reactions. So avoid it.
• It has a high chance of contamination.
• One should limit its intake.
• Consult the doctor by pregnant women and children before consuming it. Children and pregnant women should avoid it because the high content of mercury might cause a negative impact on the development of the nervous system of a fetus.
• Seafood or fish have purines in it which is harmful to people having purine-related problems. Excess purines result in an excess buildup of uric acid that could lead to the formation of kidney stones as well as gout.

References

Show More