Is Swai Fish Healthy & Safe To Eat?

Swai fish is another name for the iridescent shark, which is part of the shark catfish family. Although it is called an iridescent shark, it is definitely a fish and not a shark. The fish is mostly found in the Mekong river, a river that traverses several countries in South East Asia (China, Myanmar, Laos, Thailand, Cambodia, and Vietnam). Swai is the commonly used name for iridescent shark, though it has different names in Europe (Panga) and Asia (Basa).

Swai is a type of whitefish, similar to halibut in taste and texture. It is a pretty unknown fish in the US and Europe, but it is still sold in large quantities from Vietnam. Customers may not have heard of Swai fish, but they are probably eating it all the same.

Though Swai fish is a fairly bland and uninteresting fish, it is increasingly being used instead of more expensive whitefish such as sole. It has a decent amount of protein per serving, a mild taste, and is low in fat. But is Swai fish healthy?

In this article we are going to explore whether Swai fish is a healthy fish to eat. We’ll look at the benefits of eating it, any health concerns that have been linked to it, and we’ll even examine the effect that Swai fish farming is having on the environment. Hopefully, by the end of this article you will be able to decide for yourself whether Swai fish is a healthy option for you or not.

Nutrient Profile Of Swai Fish

The following nutritional information on Swai fish comes from the food composition database of the United States Department of Agriculture [1].

A 300g serving of Swai fish contains 186 calories, 37.17g of protein, 4g of fat, it also contains 2.88mg of iron. The protein content of Swai fish is very impressive, but in terms of nutrition there are few benefits to eating it compared to other fish.

The Benefits of Swai Fish

Below we’ve listed everything we believe to be a positive:

Swai Fish Is A Fantastic Source Of Protein

Though not as high in protein as steak, Swai fish has a decent amount per 100g, 12.39g of protein to be exact. Swai fish can be considered a high-protein alternative for non-meat eaters (pescatarians). Following a high-protein diet has numerous health benefits. Anyone interested in building muscle or strength (or both) needs to increase their protein intake to match their exercise.

A 1992 study by Tarnopolsky et al found that athletes require twice as much protein as sedentary people [2]. This is because exercise causes the breakdown of muscle fibers, and protein is required to rebuild the fibers stronger and bigger than before. Up to a certain point, the more protein you consume the more muscle you can build.

Protein is necessary for recovery from exercise, as mentioned above it is used by the body to repair and replace damaged muscle fibers. Swai fish, due to its high protein content and low-calories is a fantastic food for athletes, bodybuilders, and regular gym goers. Particularly ones who are looking for a low-cost, meat alternative.

Protein is also great for anyone dieting as it increases your metabolism slightly and increases satiety. A high protein diet can also prevent muscle loss while people are in a calorie deficit. A 2013 study by Pasiakos et al found that consuming double the amount of protein can protect fat-free mass (muscle) while also helping increase body fat loss during a short-term diet [3].

The ability of a high protein diet to increase satiety should not be underestimated, a 2004 study published in the Journal of the American College of Nutrition found that high protein diets increase weight loss partly by increasing satiety [4]. Remember that during a diet you are purposefully eating less calories than you usually do. So, increasing satiety (how full you feel) can help you to stay on target in between meals.

As you can see, Swai fish is a great food for people trying to build muscle, recover from exercise, or lose weight. This is due to its high protein content.

Swai Fish Is A Good Source Of Iron

To call Swai fish a good source of iron is stretching things a little, it contains 2.88mg of iron per 100g which is less than spinach (3.6mg per 100g). However, it is easier to eat 300mg of Swai fish than it would be to eat 300mg of spinach. A 300mg serving of Swai fish would contain 8.64mg of iron, around 50% of your recommended daily intake.

Iron is an essential nutrient, which means that you need to consume it through your diet. Usually, we tend to get enough iron from our regular diet. However, in certain situations people can be at risk of iron deficiency. If you have recently given blood or are menstruating, you may need to up your iron intake. If you have been feeling nauseous, faint, or dizzy, then you could be low on iron.

Pregnant women or those that are breastfeeding may also need to increase their iron intake, though whether Swai fish is the right choice for pregnant women is something we will be looking at later in this article.

The Health Concerns About Swai Fish

When talking about fish, it is easy to get distracted by hype. Americans in particular seem to either be massively concerned about mercury poisoning in fish or completely indifferent. You should also remember that different fish farms will treat their product differently, and that Swai fish caught in the wild may be very different to farmed Swai fish.

The issues with Swai fish are not due to the fish themselves but to the mass-production of Swai fish by (mostly) Vietnamese farmers in unsanitary conditions. As an article in the Pakistan Journal of Biological Sciences noted “The fish hatchery owners do not recruit brood fish for breeding from original sources [..] so inbreeding depression such as abnormality in growth, reduced fecundity and low disease resistance and loss of genetic variability are inevitable” [5].

So, these fish are often inbreeding and after several generations of inbreeding the fish are less healthy, and more prone to abnormalities. The article also noted that “83% of catfish farmers use chemicals/drugs due to poor water quality”, this not only shows that the fish are going to have traces of chemicals and drugs, but that the water they are in is so poor that drugs and chemicals are necessary in the first place. Not a good sign!

A 2008 study by Orban et al looked at the nutritional quality of Swai fish (also known as Sutchi Catfish) [6]. It found low levels of mercury, organochlorine pesticides, and polychlorinated biphenyls (a man-made chemical known as PBAs). The levels were low enough to be considered safe though.

An article by mentions the fact that Swai fish are often fed “food waste and other garbage from local restaurants” [7]. This increases the risk of the fish developing disease or harboring bacteria. A 2016 study found that many Swai fish fillets sold in Europe had been contaminated Vibrio bacteria [8]. Interestingly though, the study found that the fish contained much less heavy metals than had been expected, the researchers concluded that the fish was safe to eat provided it was properly cooked.

The Environmental Impact Of Swai Fish Consumption

Many articles on the internet have discussed the environmental impact of Swai fish farming. Because they are cheap to produce and are popular in many countries, people have begun to introduce them into their own countries (often illegally) in a bid to turn a quick profit.

This led to disaster in 2015 when Swai fish escaped from an illegal farm in Santander, Colombia and entered the Magdalena river. This has increased the risk of some of the native fish in this river becoming extinct.

So, Is Swai Fish Healthy Or Not?

While researching this article we found that many articles were fairly unanimous in their belief that Swai fish is dangerous and should be avoided. However, we’re going to disagree with these articles slightly. What you have to remember is that this food isn’t just imported into countries with zero checks on it. Swai fish is sold in countries all around the world, and it is likely that most of the readers of this article will have eaten it (either knowingly or unknowingly).

Many of the articles on Swai fish mention journal articles and studies from the early 2000s, which is fine science doesn’t often have a best before date. However, a lot of these journal articles mention how the farming practices are improving. They also tend to point out that the fish are safe to eat, yes they had traces of organochlorine pesticides – but in such low levels that the fish were declared fine.

That last sentence may sound insane to you, but all food is going to have traces of metals, chemicals, and many other things. If your food was held in plastic packaging then it will have traces of that plastic. If your food was sprayed with a pesticide to keep it safe from bugs then there will be a trace of that pesticide – no matter how minute. You can’t spend your life avoiding these things.

Swai fish is safe to eat. If it wasn’t then it would have been banned by the governments of the many countries that import it. Please don’t freak out if you accidentally eat some!

Does this mean that we recommend eating Swai fish with every meal? No. There isn’t really enough health benefits to justify the (admittedly tiny) risk of an unwanted side-effect. You could eat Swai fish every day for a year and be very unlucky to become ill, but it is a bland, boring, cheap fish that is low in healthy fats, and while it has a decent amount of protein there are better fish options out there.

If you really want to eat Swai fish, then our recommendation would be to pay close attention to what the label says. Not all Swai fish farms are equal. Some will be terrible, while others will be run safely and ethically. You could check the company out on Google and see what independent bodies have rated them. Alternatively, you can go with your wallet. Chances are that the cheaper the fish, the worse the conditions. Maybe spend a little more on your Swai fish?


While writing this article it was tempting to go down the “better safe than sorry” route. Just declare Swai fish unhealthy and tell you all to avoid it. But we think that this is a bit of a weak answer. There is absolutely nothing unhealthy about the Swai fish itself, if it is raised properly in sanitary conditions then the Swai fish is as healthy as any other fish out there.

The problem is that too often the Swai fish is the victim of poverty and greed. It has become more and more popular based on nothing more than the fact that it is cheap and easy to raise. The taste is average, the consistency is nothing special, and nobody is getting excited about this fish in the way that people get excited about swordfish (for example).

When a food product is bought or sold based on how cheap it is, there will always be people who try to raise it as cheap as possible. This has clearly led to a large amount of fish being raised in unsanitary and ecologically dangerous conditions. The story of a fish indigenous to Vietnam overrunning a river in Colombia is terrifying.

But let’s not tar all Swai fish farmers with the same brush. Just because some farms are bad doesn’t mean that they all are.

There is no real reason to eat Swai fish. No meal will be improved using Swai over any other white fish. But if you do eat it, don’t panic. It’s fine. You’ll be fine. You’re not going to die of mercury poisoning, instead you’ll live a long healthy life eating bland, cheap fish. You tell us which scenario is worse!