Tuna is one of the most commonly consumed fish in the world. Canned tuna is especially popular in the United States due to its affordability, versatility, and ease of storage. There are many types of tuna, but albacore, yellowfin, and skipjack make up the majority of tuna consumed worldwide.
Tuna is a nutritious food, providing protein, essential vitamins, minerals and fatty acids. Eating tuna has numerous health benefits, from promoting satiety to protecting heart health.
However, there are significant environmental and health concerns surrounding tuna consumption.
Here’s everything you need to know about tuna, including its potential health benefits, nutrition, and risks.
Design: Health/Stocksy
Tuna is rich in protein, with over 40 grams per 172 gram can.
Protein supports satiety by slowing digestion and increasing satiety-inducing hormones such as cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1), making you feel fuller after a meal. Studies have shown that regularly eating seafood, such as tuna, can reduce your total calorie intake and promote weight loss. In fact, studies have shown that eating seafood frequently can reduce your calorie intake by up to 9% compared to other protein sources such as chicken or beef.
Eating high-protein foods like tuna can also help you preserve muscle mass while losing weight to achieve and maintain a healthy body composition, which is essential for optimally maintaining your resting metabolic rate (RMR) – the calories you burn while at rest.
In addition to being high in protein, tuna contains no carbohydrates, making it an excellent addition to low- or very low-carb diets, such as the ketogenic diet, which may help promote weight loss.
Tuna is packed with nutrients, some of which are not found in other foods. For example, seafood is the primary dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), omega-3 fatty acids that play important roles in health. For example, EPA and DHA are important for nervous system function and have powerful anti-inflammatory effects in the body.
Research shows that a diet high in omega-3 fatty acids may help reduce the risk of common health conditions, including heart disease, colon cancer, and cognitive decline.
Tuna is also a good source of vitamin D, a fat-soluble nutrient that’s essential for bone health, immune function, and more. Vitamin D isn’t found in many foods, and eating seafood like tuna is one of the best ways to increase your dietary intake of vitamin D. One 172-gram can of tuna contains 17 percent of your daily vitamin D needs, making it a great way to boost your levels of this important vitamin.
Eating tuna also increases your intake of vitamins B6, B12, selenium, vitamin E, and magnesium, all of which are essential for good health.
Tuna contains a variety of nutrients that support and protect health. For example, tuna’s high protein content and low carbohydrate content make it a good choice for people with issues regulating blood sugar, such as those with prediabetes or diabetes. Tuna is zero carbohydrates and high in protein, making it a great option for a blood sugar-friendly meal or snack.
Seafood consumption is generally associated with a lower risk of disease and death from all causes. A 2020 meta-analysis review of 34 studies found that for every 100 grams of seafood consumed per day, there was an 8% lower risk of death from all causes, a 12% lower risk of coronary heart disease, and a 25% lower risk of heart attack. Frequent seafood consumption was also found to be associated with a lower risk of depression and liver cancer.
Seafood such as tuna is rich in anti-inflammatory and antioxidant nutrients, including omega-3 fats, vitamin D, and selenium, which may help prevent the onset of disease by reducing cell damage, promoting healthy blood vessel function, and protecting against risk factors such as high blood pressure.
Tuna is an excellent source of nutrition, packed with protein, healthy fats, vitamins and minerals.
The nutritional content of one can (172 grams) of canned tuna in water is as follows:
- calorie: 220
- protein: 40.6 g
- fat: 5.11 g
- carbohydrates: 0 grams
- B6: 0.373 milligrams (mg) or 22% of the recommended daily value (DV)
- Niacin: 9.98 mg or 62% of the recommended daily intake
- B12: 2.01 micrograms (mcg) or 84% of the recommended daily intake
- Vitamin D: 3.44 mcg or 17% DV
- Vitamin E: 1.46 mg or 10% of the recommended daily intake
- Rin: 373 mg or 30% of the recommended daily intake
- magnesium: 56.8 mg or 14% of the recommended daily intake
- selenium: 113 mcg or 205% of the recommended daily intake
Tuna is a concentrated protein source, with one can providing over 40 grams of high-quality protein.
In addition to protein, tuna is rich in B vitamins, especially vitamin B12, a nutrient needed for red blood cell production, metabolism, nerve function, DNA synthesis and other important processes in the body.
Seafood such as tuna is one of the few foods that is rich in vitamin D, a fat-soluble nutrient needed for bone health, immune function and reducing inflammation. Vitamin D deficiency or insufficiency is very common, and including vitamin D-rich foods in your diet can help maintain healthy levels of this important vitamin.
Tuna is also a good source of a variety of other vitamins and minerals, including vitamin E, magnesium, and selenium.
Although tuna may provide important nutrients and support health in a variety of ways, there are environmental and health concerns about eating tuna.
One of the main problems associated with consuming tuna is that it contains high amounts of mercury, a heavy metal that is easily absorbed by the body. If your diet includes foods high in mercury, this heavy metal can build up over time and harm your health in a variety of ways, including impairing the health of your nervous and immune systems and increasing your risk of heart disease.
Unfortunately, tuna is considered one of the leading food sources of mercury worldwide, and eating tuna regularly increases your risk of high mercury levels. Keep in mind that due to its larger size and longer life span, albacore tuna contains approximately three times more mercury than canned light tuna, which contains smaller species such as skipjack tuna. For this reason, the FDA recommends limiting your consumption of albacore tuna to once a week and avoiding other seafood the rest of the week. The FDA recommends limiting your consumption of light tuna to less than three times a week.
In addition to mercury, seafood such as tuna may be contaminated with microplastics, tiny pieces of plastic that pollute the marine environment and accumulate in fish. Microplastics contain compounds that are harmful to the human body, such as polybrominated diphenyl ethers (PBDEs) and bisphenol A (BPA). While the long-term health effects and toxicity of microplastics are still being studied, experts recommend limiting consumption of seafood known to be high in microplastics, such as tuna, to protect your health and reduce your exposure to these harmful substances.
In addition to health concerns, there are also environmental issues associated with tuna consumption. Increasing global demand for fish such as tuna is putting intense pressure on the marine environment, leading to overfishing and the destruction of delicate marine habitats.
While reducing your overall seafood consumption is the best way to protect marine life and the environment, choosing more sustainable tuna products also helps. Monterey Bay Aquarium Seafood Watch has a database to help you choose tuna that has been sustainably caught or farmed and not overfished.
Although tuna is a healthy choice, it is important to purchase tuna that is low in mercury and limit your intake of tuna that is high in mercury.
The FDA recommends choosing light canned tuna, including skipjack tuna, and limiting consumption of albacore and bigeye tuna, which are higher in mercury.
Also, because tuna consumption comes with environmental concerns, you can reduce your environmental impact by limiting your tuna intake and choosing other, more environmentally friendly sources of protein, such as sardines, shellfish, and plant-based protein sources like beans.
If you want to enjoy tuna, there are a few ways to incorporate it into your diet.
- Serve canned tuna with green salads and grain bowls.
- Make a simple tuna salad using canned tuna, chopped celery, and mayonnaise or mustard.
- Try substituting a tuna burger for a beef burger.
- Enjoy tuna in wraps and sandwiches
Although tuna can be purchased fresh, many people prefer canned tuna for its versatility, cost, and shelf life.
Canned tuna can be stored for up to five years, making it a convenient source of protein.
Tuna is a widely consumed fish that is rich in protein, B vitamins, omega-3 fats, and several other important nutrients.
Eating more seafood may have health benefits, such as reducing the risk of heart disease and helping you maintain a healthy weight, but tuna is high in toxins such as mercury and isn’t the most sustainable seafood choice.
If you want to include tuna in your diet, it’s important to choose sustainably caught tuna that is low in mercury and avoid tuna that is high in mercury.
