Why is Swai Fish Bad for You: Uncovering Hidden Health Risks

Swai fish has become increasingly popular due to its affordable price and mild taste, making it an attractive option for many consumers. However, you might be unaware of the various concerns surrounding this fish and why it might not be the healthiest choice for your dinner table.

In this article, we will discuss the main reasons why swai fish can be harmful to your health. We will explore issues such as the presence of dangerous microbes, the use of antibiotics in fish farms, unhygienic water conditions, and frequent mislabeling of fish. By understanding these concerns, you can make more informed decisions about whether or not to include swai fish in your diet.

We will also provide you with safer and more sustainable seafood options that you can consider as alternatives to swai fish. Armed with this knowledge, you can continue to enjoy the benefits of incorporating fish into your meals without compromising your health or the environment.

What Is Swai Fish?

Why is Swai Fish Bad for You

Swai fish, also known as pangasius, panga, Vietnamese catfish, or iridescent shark, is a type of freshwater fish native to Southeast Asia, particularly Vietnam. In its natural habitat, swai can be found in rivers such as the Mekong and Chao Phraya. The species has grown in popularity in recent years due to its affordability and mild, delicate flavor.

This fish is typically farm-raised in Vietnam, where it is often cultivated in large-scale fish farms. These fish are kept in ponds or floating cages in rivers, where they are fed a diet consisting of both commercial feed and wild-caught fish.

While some farms operate responsibly and maintain high standards for the welfare of the fish and their environment, others have faced criticism for lax inspection rules and health violations.

Market Forms

Swai fish is typically sold in various forms, such as fresh, frozen, or battered fillets. When selecting swai at your local market, look for fillets that are firm, moist, and white or off-white in color. Be careful to purchase from reliable suppliers to ensure the fish has been raised in optimal conditions.

Ways of Cooking

There are numerous ways to cook swai fish to suit your taste preferences. Here are a few methods you can try:

  • Baking. Preheat your oven to 375°F (190°C), season the fillets with your favorite herbs and spices, and bake for 15 to 20 minutes or until the fish flakes easily with a fork.
  • Grilling. Lightly oil your grill grates, then cook the seasoned swai fillets over medium heat for 3 to 4 minutes per side, or until they reach an internal temperature of 145°F (63°C).
  • Pan-frying. Heat a small amount of oil in a pan over medium-high heat, then cook the seasoned swai fillets for 3 to 4 minutes per side, or until golden brown and cooked through.
  • Poaching. Bring a pot of lightly seasoned water, broth or wine to a gentle simmer, then add your swai fillets and cook for 4 to 5 minutes, or until their internal temperature reaches 145°F (63°C).

Remember to handle and store your swai fish properly to ensure its quality and safety for consumption.

Nutrition Information

Pangasius fish consumption is typically endorsed due to its rich provision of lean protein and beneficial omega-3 fatty acids that promote cardiovascular health.

Swai, a commonly consumed fish, provides a moderate level of protein compared to other fish species. However, it falls short when it comes to omega-3 fats, according to various reliable sources.

A raw 4-ounce (113-gram) portion of swai provides the following nutritional content:

  • Calories: 70
  • Protein: 15 grams
  • Fat: 1.5 grams
  • Omega-3 fat: 11 mg
  • Cholesterol: 45 grams
  • Carbs: 0 grams
  • Sodium: 350 mg
  • Niacin: 14% of the daily recommended intake
  • Vitamin B12: 19% of the daily recommended intake
  • Selenium: 26% of the daily recommended intake

To contrast, an equal serving of salmon furnishes 24 grams of protein and a much higher level of omega-3 fat, ranging from 1,200 to 2,400 mg. American catfish, on the other hand, delivers 15 grams of protein and between 100 to 250 mg of omega-3 fat per 4-ounce (113 gram) serving.

The sodium content of swai can vary depending on how much sodium tripolyphosphate, a moisture-retaining additive, is utilized in the fish’s processing.

While swai can be a superb source of selenium and an adequate supplier of niacin and vitamin B12, the actual amounts can fluctuate depending on the fish’s diet.

Unfortunately, swai are not known for maintaining particularly nutritious diets. Their typical feed includes rice bran, soy, canola, and fish by-products. It’s important to note that the soy and canola components are often genetically modified, a practice that is a subject of ongoing debate due to potential health and environmental impacts.

Health Benefits of Swai Fish

Lean protein

Swai fish is a good source of lean protein, which is essential for building and repairing body tissues, producing enzymes and hormones, and supporting overall growth and development.

Supports heart health

Incorporating swai fish into your diet can contribute to better heart health. The omega-3 fats found in swai fish can help lower your risk of heart disease by reducing inflammation and improving the health of your blood vessels.

DHA for brain health

Swai fish contains DHA, which is an essential omega-3 fatty acid that can support your brain health. DHA is crucial for the proper functioning of your brain and plays a significant role in cognitive development and maintaining a healthy brain throughout your life.

Pros and Cons of Swai Fish

Swai fish has become popular due to its affordability and mild flavor. However, like any food, there are pros and cons to consuming swai fish.

Pros of eating swai fish

  1. Affordability. Swai is typically less expensive than many other types of fish, making it an affordable protein source.
  2. Mild flavor. Swai has a delicate, slightly sweet flavor and a light, flaky texture, which can be appealing to those who do not enjoy “fishy” tasting seafood.
  3. Versatility. Its mild flavor and texture make swai adaptable to a variety of cooking methods and recipes, ranging from grilling and frying to baking and poaching.
  4. Nutrition. Swai offers a good amount of lean protein, is low in fat and calories, and provides essential nutrients such as selenium, niacin, and vitamin B12.

Cons of eating swai fish

  1. Farming practices. Swai is primarily farm-raised, often in conditions that are less regulated than those in many Western countries. This could potentially lead to exposure to harmful substances or antibiotics.
  2. Low omega-3 content. Compared to other fish like salmon or mackerel, swai is low in heart-healthy omega-3 fatty acids.
  3. Environmental impact. Some farming practices for swai have been criticized for their environmental impact, including water pollution and the destruction of mangroves.
  4. High sodium content. Swai can contain high levels of sodium, particularly when sodium tripolyphosphate is used during processing to retain moisture.

Related Studies

A study investigating the safety of frozen pangasius catfish and Nile tilapia fillets exported to Poland, Germany, and Ukraine found minor safety concerns. Although levels of heavy metal residues and histamine were below safety limits, 70-80% of pangasius samples contained Vibrio species, bacteria that can cause foodborne illness.

No E. coli or Vibrio species were detected in the tilapia samples. Despite varied freshness indicators, all samples had low rancidity levels, suggesting good preservation. The study concluded that, aside from Vibrio spp. contamination, there were no significant safety issues with these fish fillets, but it emphasized the risk of eating pangasius raw or undercooked.

A study assessing mercury levels in panga fish (Pangasius hypophthalmus), a popular and affordable seafood choice, revealed variable mercury concentrations across 80 different samples. With mercury levels ranging from 0.10 to 0.69 mg/kg, an average consumption of 350g of panga per week would account for approximately 32% of the Tolerable Weekly Intake (TWI) of mercury for women and 27.5% for men.

The study recommends rigorous control of mercury content in panga and suggests limiting its consumption, especially in children, due to the potential risks of mercury ingestion.

Mislabeling of swai fish is another prevalent issue. Researchers from the University of Hawaiʻi found that 21% of seafood sold in the greater Honolulu area was mislabeled, with swai fish being sold under various names in place of more expensive fish species. This deceptive practice can lead you to consume a lower-quality fish without realizing it.

What Do Health Experts Say About Swai Fish?

As someone concerned about their health, it’s important to know what health experts have to say about swai fish. The nutritional value of swai fish is relatively moderate, providing a decent amount of protein, selenium, niacin, and vitamin B12, but very little omega-3 fat. However, there are several concerns related to swai fish consumption that you should be aware of.

Firstly, swai fish farming practices have been criticized for lax inspection rules and health violations. Dangerous microbes have been found in swai fish, which can pose a threat to your health. Additionally, some swai fish farms are known to use antibiotics to treat sick fish.

The excessive use of antibiotics in fish farming can contribute to an increase in antibiotic-resistant bacteria, potentially making it harder to treat infections in humans.

Another concern is the water conditions in which swai fish are raised. Polluted and contaminated water can harm the quality of the fish you consume. Moreover, swai fish farming practices have been linked to the use of growth hormones and antibiotics, which might pose potential health risks.

Furthermore, the issue of seafood fraud is prevalent, with swai fish being frequently mislabeled as different types of fish. This makes it difficult for you to know exactly what type of fish you’re consuming and whether or not it has been raised in a safe, regulated environment.

In terms of regulation, swai fish imported into the United States is subject to inspection by the Food and Drug Administration (FDA). However, according to some sources, only a small percentage of the imported fish is tested, which can lead to potential health risks for consumers.

While the nutritional facts of swai fish might look favorable, you should be cautious about consuming it due to the concerns raised by health experts. It can be challenging to determine whether the swai fish you purchase is of good quality and raised in safe, regulated environments.

Who Should Avoid It?

Swai fish is often considered as an unhealthy choice due to factors like pollution, use of growth hormones, antibiotics, and contaminated water. Therefore, specific groups of people should avoid consuming Swai fish:

  • Pregnant women: Pregnant women should avoid consuming Swai fish due to the potential presence of heavy metals and other contaminants that could harm the developing fetus. It’s essential to choose safer seafood options with low mercury levels, like salmon and shrimp, during pregnancy.
  • Older adults: As you age, your immune system becomes less robust, making it important to avoid consuming contaminated food products, including Swai fish. Older adults should stick to eating well-cooked, high-quality seafood to lower the risk of foodborne illness.

Alternatives to Swai Fish

Instead of consuming swai fish, which might have questionable farming practices and potential health risks, consider incorporating these healthier, more sustainable alternatives into your diet:

  • Salmon: Rich in omega-3 fatty acids, vitamins, and high-quality protein, salmon is a popular and nutritious choice. Aim for wild-caught Alaskan salmon to ensure the most sustainable option.
  • Tilapia: Offering a mild taste, tilapia is another white fish that can be more sustainable when farmed according to best practices.
  • Shellfish: Including options like oysters, clams, and mussels, shellfish are not only nutritious but also good for the environment as they help filter water and maintain aquatic ecosystems.
  • Albacore Tuna: A versatile option, albacore tuna is rich in protein and lower in mercury compared to other tuna species. However, always opt for pole-caught tuna for the most sustainable practice.
  • Grouper: Be sure to select a sustainably-caught grouper, as it can be rich in protein and provide essential nutrients, making it another healthy alternative to swai.
  • Flounder: With a delicate texture, flounder is a versatile option best chosen from U.S. Atlantic waters for greater sustainability.
  • Herring: As a small, oily fish similar to sardines, herring can be an eco-friendly and nutrient-rich choice when sustainably caught.
  • Mackerel: Packed with omega-3s, mackerel is another oily fish that’s healthier than swai when responsibly sourced.
  • Perch: Opt for wild-caught perch, preferably from the Gulf of Mexico, to avoid Swai’s shortcomings and enjoy a nutritious, white-fleshed fish.
  • Sturgeon: When sourced from responsible fisheries, wild sturgeon can offer a delicious and sustainable alternative, though it is essential to avoid over-exploited varieties.

By incorporating these healthier and more eco-friendly alternatives into your diet, you can enjoy the benefits of seafood without the potential drawbacks of swai fish.


Swai fish may appear to be a cheaper alternative for your seafood needs, but there are several potential health and sustainability concerns. Overcrowded fish farm conditions and polluted water provide an environment that can lead to dangerous microbes and heavy metal contamination. In addition, the presence of antibiotics used to treat sick fish may pose problems.

As a consumer, you should be aware of the lack of inspection in swai fish production. This increases the risk of health violations and diseases such as parasitic, bacterial, and Sporozoa infestations and infections. Furthermore, the frequent mislabeling of swai as other types of fish not only deceives you, but also contributes to the environmental and economic issues surrounding fish farming.

While fish consumption has numerous health benefits, such as protein and omega-3 fatty acids, you should consider the downsides of swai fish in comparison to other seafood options. Seek out healthier alternatives that are more responsibly sourced and provide better nutritional value. By avoiding swai fish, you can make an informed decision to support your health and the environment.


Is Swai fish healthy to eat?

Swai fish can be a good source of protein and essential vitamins like B12 and niacin. However, it’s relatively low in omega-3 fatty acids compared to other types of fish like salmon or mackerel.

Does Swai fish contain mercury?

All fish contain some mercury, but the levels can vary. While Swai isn’t a top-mercury fish, its mercury levels can vary depending on environmental factors. Consumers should be aware of this, especially pregnant women, nursing mothers, and young children.

Is Swai fish high in sodium?

The sodium content in Swai can vary. Some Swai fish can be high in sodium due to the use of sodium tripolyphosphate during processing, an additive used to retain moisture.

Is the Swai fish farming process safe and healthy?

Some concerns have been raised about Swai fish farming practices, including the use of antibiotics, the quality of feed, and the potential environmental impact. It’s recommended to choose Swai fish from sources that follow responsible farming practices.

How often should Swai fish be consumed?

This depends on individual dietary needs and the source of the Swai fish. Given the potential concerns about mercury and sodium content, it may be wise to limit consumption and balance it with other types of fish and protein sources.


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  • Marixie Manarang, MT, undergrad MD

    Marixie Manarang is licensed Medical Laboratory Scientist and an undergraduate of Doctor of Medicine (MD). For one year, she completed her internship training in a government hospital, primarily catering to retired veterans and their dependents. Through her preceptorships in medical school, she gained exposure to patients from various medical departments. Marixie’s passion for writing stems from her excellent medical background, being a mother, and a strong desire to assist the elderly and others in need. Education: Our Lady of Fatima University Doctor of Medicine (MD), Doctor of Medicine (2012-2015), Angeles University Foundation Doctor of Medicine (MD), Doctor of Medicine (2009-2011), Angeles University Foundation Bachelors, Medical Technology (2004-2009)






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