What is tuna fish?
![Canned tuna is an inexpensive source of protein that can be safely stored on your shelf. Fish is a very healthy protein choice and eating canned tuna once or twice a week is safe.](https://images.medicinenet.com/images/article/main_image/can-you-eat-tuna-while-pregnant.jpg?output-quality=75)
Canned tuna is an inexpensive source of protein that can be safely stored on your shelf. Tuna can contain small amounts of mercury but has many health benefits and is safe to eat a few times per week.
Tuna are large ocean-dwelling fish, some weighing almost 2000 pounds. Tuna typically eat smaller fish and can travel huge distances in search of food and mates.
There are several tuna species, but only a few are usually sold to eat. The most common species of tuna for sale in your grocery store are skipjack, albacore, yellowfin, and bigeye.
What is canned tuna?
Tuna steaks can be bought fresh or frozen, but this fish is usually seen in a can. Canning facilities receive large amounts of caught tuna, which usually arrives frozen. The fish is then cooked, and the meat is removed from the bones.
The meat is put into cans with broth, salt, oil, or water. These cans are then sealed and sterilized. They’re also inspected to make sure that the cans in a batch are high quality and safe to eat.
How healthy is canned tuna?
In general, fish is a very healthy protein choice and an important addition to any diet. Canned tuna is an especially great option because it is usually inexpensive and shelf-stable.
Canned tuna nutrition information
Canned tuna is high in protein, low in fat, and contains important vitamins and minerals such as omega-3 fatty acids, vitamin D, calcium, and riboflavin.
Tuna’s nutritional profile changes depending on how it’s packed. In a 100-gram serving, canned light tuna packed in water typically has:
- 85 calories
- 19 grams of protein
- 0.6 grams of fat
- Less than 0.1 grams of carbohydrates
The same serving of canned light tuna packed in oil contains:
- 198 calories
- 29 grams of protein
- 8 grams of fat
- Less than 0.1 grams of carbohydrates
Both of these tunas are healthy protein choices, but it’s essential to pay attention to what your tuna is packed in if you want to avoid excess fat or calories.
A major reason to eat canned tuna is because of its high levels of omega-3 fatty acids. Omega-3 fatty acids serve many important bodily functions, such as:
- Supporting the membranes that hold cells together
- Managing blood clotting
- Helping arteries to contract and relax
- Regulating inflammation
Omega-3 fatty acids are essential for heart health. These fats help to lower blood pressure and cholesterol and help blood vessels work more efficiently.
One study examining patients after a heart attack found that fatty acid supplements reduced the risk of future heart attacks and death.
Although they’re an important part of a healthy heart, omega-3 fatty acids aren’t produced in the body. Instead, we have to get them from food. There are three main omega-3s, two of which are usually found in fish like canned tuna. Eating canned tuna is a great way to ensure you’re getting enough omega-3s in your diet.
Mercury levels in fish
Canned tuna has many health benefits, but one concern is its mercury level. Mercury is a toxic chemical that occurs naturally or can be released into the environment due to pollution from burning fossil fuels.
After being released into the air, mercury eventually settles into the sand at the bottom of lakes and oceans. Bacteria in the sand convert mercury into a similar compound called methylmercury, which can circulate in the water and get ingested by fish as water passes over their gills.
Large fish like tuna usually have higher mercury concentrations because they eat smaller fish. These smaller fish also contain some mercury, and eating many of them can cause mercury levels to rise in large fish like tuna.
Although mercury is a toxic chemical, it’s usually not present in tuna in large enough quantities to cause serious issues. Canned tuna’s health benefits seem to outweigh any small negative effect of its mercury concentration.
In general, eating canned tuna once or twice a week is safe. It’s also good practice to add a variety of fish to your diet, including smaller species and shellfish with lower mercury levels than large species like tuna.
Are all canned tunas the same?
When considering which canned tuna to buy, it’s essential to look at the can to see the exact type you’re buying.
Tuna can come packed in water, oil, or broth, and can be salted or unsalted. Tuna in oil typically has more calories and fat than tuna packed in water. If you’re watching your sodium levels, make sure that you buy unsalted canned tuna.
Canned tuna typically contains either albacore or skipjack tuna, and cans are usually marked as either “albacore” or “chunk light.” Albacore tuna typically has higher concentrations of mercury than chunk light tuna and should be eaten only once or twice a week. Chunk light tuna is safe to eat two or three times a week.
I’m pregnant or breastfeeding. Should I still eat canned tuna?
It’s important to get enough omega-3 fatty acids when pregnant. Omega-3 fatty acids are critical for the development of the brain and spinal cord.
Canned tuna is safe to eat once or twice a week while pregnant or breastfeeding, but pregnant and nursing people should choose chunk light because of its lower mercury content.
Canned albacore tuna is safe to eat once per week, but other large fish such as sharks, swordfish, and king mackerel should be avoided entirely.
Is tuna good for you?
Canned tuna is a high-protein, low-fat food that is inexpensive and can be stored for long periods. It contains important vitamins and minerals such as omega-3 fatty acids that are essential for heart health and fetal development.
Canned tuna contains mercury but is still safe to eat a few times per week. When choosing canned tuna, opt for lower mercury options like chunk light.
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SLIDESHOW
Foods That Aren't as Healthy as You Think See SlideshowHealth Solutions From Our Sponsors
Colorado Integrated Food Safety Center of Excellence Food Source Information: "Canned Tuna."
Food and Drug Administration: "Advice About Eating Fish For Those Who Might Become or Are Pregnant or Breastfeeding and Children Ages 1-11 Years," "Questions & Answers from the FDA/EPA Advice about Eating Fish for Those Who Might Become or Are Pregnant or Breastfeeding and Children Ages 1 to 11 Years."
FoodData Central: "Fish, tuna, light, canned in oil, without salt, drained solids," "Fish, tuna, light, canned in water, drained solids."
Harvard Health Publishing: "What to do about mercury in fish."
Harvard T. H. Chan School of Public Health: "Fish: Friend or Foe?," "Omega-3 Fatty Acids: An Essential Contribution."
Journal of the American Medical Association: "Fish intake, contaminants, and human health: evaluating the risks and benefits."
The Lancet: "Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico."
Washington State Department of Health: "Health Benefits of Fish."
Washington State University Consumer Food Safety: "Risk of Mercury in Fish."
World Wildlife Foundation: "Tuna."
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