Is swai healthy to eat?

Swai fish, also known as iridescent shark, tra, basa, or pangasius, is a popular fish that is often served in restaurants and sold in grocery stores. But there are some concerns about whether swai fish is actually healthy to eat. Here is a comprehensive look at the nutrition, health benefits, safety, and sustainability issues related to eating swai fish.

What is swai fish?

Swai fish belongs to the Pangasiidae family and is native to the rivers and estuaries of Southeast Asia, including Vietnam, Cambodia, and Indonesia. It is commonly farmed in the Mekong Delta region of Vietnam. The scientific name for swai fish is Pangasius bocourti.

Some key facts about swai fish:

  • Swai is a white-fleshed fish with mild flavor and light, flakey texture.
  • It is an omnivorous bottom feeder that eats plants and smaller organisms.
  • Farmed swai reach market size of 1.1-1.65 lbs in 6-8 months.
  • U.S. imports of swai fillets increased dramatically from 2002 to 2007 but have stabilized in recent years.
  • Vietnam accounts for 90% of global swai exports.

Nutrition facts of swai fish

Here is the nutrition information for a 4-ounce serving of raw swai fillet (112 grams):

Nutrient Amount
Calories 99
Protein 21 g
Total Fat 1 g
Saturated Fat 0.3 g
Polyunsaturated Fat 0.4 g
Monounsaturated Fat 0.3 g
Cholesterol 57 mg
Sodium 74 mg
Potassium 348 mg
Carbohydrates 0 g

As you can see, swai is high in protein, low in fat, and has negligible carbs. It provides a good source of potassium and relatively low amounts of sodium and cholesterol compared to other fish.

Benefits of eating swai fish

Here are some of the main health benefits associated with eating swai fish:

Lean source of protein

Swai provides 21 grams of protein per 4-ounce serving, making it an excellent source of this important nutrient. Protein plays vital roles in building muscle mass, supporting neurological function, maintaining bone strength, and more.

Low in mercury

Many types of seafood contain concerning levels of mercury, a toxic heavy metal. However, swai is not a high-mercury fish. Tests show farmed swai contains only trace amounts of mercury, making it a safer choice.

Rich in vitamins and minerals

Swai provides B vitamins, selenium, vitamin D, phosphorus, and omega-3 fatty acids. These nutrients support immune function, brain health, cardiovascular health, and more. Swai has more vitamin B12 and twice as much selenium as tilapia.

Heart-healthy fats

While low in total fat, swai contains primarily polyunsaturated and monounsaturated fats. These types of fats may help lower cholesterol and triglyceride levels.

Mild flavor

The mild taste and flaky texture make swai fish adaptable to many recipes and cooking methods. It takes on the flavors of sauces, herbs, and spices nicely.

Safety and sustainability concerns

While swai does have some nutritional benefits, there are also some important safety and sustainability issues to consider:

Farmed origin

Most swai sold commercially comes from large-scale aquaculture operations in Vietnam and other Southeast Asian countries. Some concerns have been raised about the use of antibiotics, fungicides, and questionable manufacturing practices in swai farming.

Potential contaminants

Several studies have found traces of antimicrobial residues, metals, and microplastics in swai from Vietnam. Proper cooking can help kill bacteria, but chemical residues may remain.

Overfishing of wild stocks

The Pangasiid catfish family is vulnerable to overfishing throughout Southeast Asia. Wild populations have declined, putting further pressure on aquaculture operations.

Deforestation and habitat loss

Conversion of mangroves and other natural habitats to swai aquaculture ponds contributes to deforestation, pollution, and biodiversity loss in major swai-farming regions.

Lack of environmental regulations

Lax regulations and oversight in the swai export industry have raised concerns about the impacts on natural ecosystems. There is limited publicly available information on swai aquaculture practices.

Comparison to other popular fish

How does swai nutrition and mercury levels compare to some other popular fish choices?

Fish Protein per 4 oz Total Fat per 4 oz Mercury Level*
Swai 21 g 1 g Low
Tilapia 22 g 2 g Low
Cod 19 g 1 g Low
Salmon 22 g 6 g Low to moderate
Tuna 24 g 1 g Moderate to high
Swordfish 23 g 5 g High

*According to FDA and EPA mercury advice

In terms of protein, fat, and mercury, swai is comparable to tilapia and cod. It contains more mercury than wild-caught salmon but less than tuna and swordfish.

Is swai fish healthy? Final verdict

Overall, swai fish supply lean protein, vitamins, minerals, and heart-healthy fats. However, the farmed origin and lack of environmental oversight for swai raise important concerns.

For a frequent seafood choice, domestic fish like catfish and trout may be more sustainable options. Eating a variety of fish is ideal for health and to avoid overfishing any one species.

If you do choose to eat swai occasionally, sticking to U.S. or Australian imported fish may help avoid some of the chemical contamination risks of Vietnamese swai. Cooking swai thoroughly and following safe handling practices also helps reduce any safety issues.

While not the most eco-friendly fish choice, swai in moderation can fit into an overall balanced diet. Combining it with alternative protein sources like beans, lentils, and poultry can help mitigate potential sustainability impacts.

Frequently asked questions

Is swai fish healthy?

Yes, swai is relatively healthy due to its high protein, low fat, and low mercury levels. However, sustainability and contamination concerns with imported swai from Vietnam need to be considered.

Is swai high in mercury?

No, swai is low in mercury. Tests show mercury levels in farmed swai are minimal. Much higher mercury fish include tilefish, swordfish, shark, and tuna.

Is swai healthier than tilapia?

Swai and tilapia have comparable nutritional profiles. Swai contains slightly more protein and less fat per serving than tilapia. Both are low mercury fish. Tilapia sold in the U.S. is generally considered more sustainable than imported swai.

Is swai fish sustainable?

No. Most swai is farmed unsustainably in Vietnam and Thailand. The rapid growth of swai aquaculture has contributed to habitat destruction, chemical pollution, and overfishing of wild pangasius stocks. Buying domestic or sustainably raised fish is a better environmental choice.

Is swai fish safe to eat?

Swai from Vietnam may contain traces of chemicals like antimicrobials according to some studies. Proper cooking, freezing, and handling make swai safe to eat but chemical residues may remain. U.S. inspected swai is less risky.

Is swai fish boneless?

Yes, commercially sold swai fillets are boneless white fish fillets. They have been skinned, trimmed, and deboned.

What does swai taste like?

Swai has a mild, light flavor and flaky texture similar to cod and tilapia. It tends to take on the flavors of sauces, seasonings, and oils easily.

Is swai fish expensive?

No, swai fish is relatively inexpensive, especially compared to wild-caught fish. Low farming costs and labor costs in Vietnam keep swai prices affordable. Its cheap price makes it popular at restaurants and grocers.


Swai fish offers lean protein and nutrition, but its farmed Asian origins raise sustainability and potential contamination issues. Eating swai in moderation along with a diverse seafood selection is likely fine for most healthy adults. However, eco-conscious seafood lovers may prefer to choose domestic options like catfish or trout that align better with sustainability.

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