Salmon is often appreciated for its health benefits.
This is a fatty fish that contains Omega-3 fatty acids that most people don't have enough.
Unfortunately, not all salmon are the same.
Today, many of the salmon we eat is not caught in the wild but is kept in fish farms.
The difference between wild salmon and farmed salmon
Wild salmon are caught in the wild, its natural environment is oceans, rivers and lakes.
But half of salmon sold worldwide comes from a place called fish farm, also known as .
Global annual salmon production has increased from 27,000 upwards 1 million tons in the past two decades .
While wild salmon eat other organisms in the natural environment, farmed salmon are fed high-fat processed foods to produce larger fish .
Wild salmon is still available, but global reserves have halved in just a few decades .
Summary: The production of farmed salmon has increased significantly over the past two decades. Farmed salmon have a totally different diet and habitat than wild salmon.
There are some important differences in nutritional composition
The nutritional composition of half a slice (198 grams) of wild salmon is on the left. On the right is the data for farmed salmon .
As you can see in the table, the nutritional differences between wild salmon and farmed salmon are significant.
Farmed salmon has a much higher fat content, it contains a lot more Omega-3, much higher Omega-6 fatty acids and 3 times higher saturated fat. It also contains calories 46% more, mostly from fat.
Farmed salmon also contains some vitamin C added to animal feed.
In contrast, wild salmon has a high mineral content, including potassium, zinc and iron.
Summary: Wild salmon contains more minerals. Farmed salmon contains lots of vitamin C, saturated fat, polyunsaturated fatty acids and calories.
The difference in polyunsaturated fat content
There are two types of polyunsaturated fats, omega-3 and omega-6 fatty acids.
These fatty acids play an important role in the human body.
We need both in the diet, otherwise we will get sick. That is why they are called "essential" fatty acids (EFAs).
However, we need to have these fatty acids in a certain balance.
Today, most people eat too much Omega-6, and the delicate balance between these two fatty acids is pulled back to Omega-6.
Many scientists speculate that this may increase inflammation and may play a role in chronic epidemics such as heart disease and other diseases .
It is worth noting here: farmed salmon has a total amount of fat three times higher than that of wild salmon, but most of these fats are Omega-6 fatty acids .
For this reason, the ratio of Omega-6: Omega-3 in farmed salmon is high three times compared to wild salmon.
However, I don't really think this is a worrying cause. Although farmed salmon contains Omega-6, O6: O3 ratio is still great (1: 3-4), it is only worse than wild salmon 1:10 .
Salmon, both Wild fish and fish help improve overall consumption of Omega-3 for most people and are often recommended for that purpose.
In a 4-week study of 19 volunteers, eating Atlantic salmon twice a week increased levels of DHA (an amount of omega-3 fatty acids) in the blood to 50% .
Summary: Farmed salmon have much higher omega-6 fatty acids than wild salmon, but the number is still too low to cause concern.
Farmed salmon contain more pollutants
Fish tend to accumulate contaminants from their environment.
These contaminants are found in the water they live in, as well as the food they eat .
But farmed salmon has a higher concentration of pollutants than wild salmon .
European farms have more pollutants than American farms, but the species from Chile seem to have the least amount of these substances .
Some contaminants include (PCBs), and some chlorinated pesticides.
Arguably the most dangerous contaminant found in salmon is PCB, which is closely related to cancer and other health problems .
One study investigated more than 700 salmon samples around the world and found that the average PCB concentration in farmed salmon was higher 8 times wild salmon .
FDA for these levels of contamination is safe, but (EPA) don't think so.
Researchers suggest that if EPA guidelines are applied to farmed salmon, it is recommended to limit the use of salmon no more than once a month.
However, many argue that the benefits of consuming Omega-3 from salmon are greater than health risks from contaminants, which is a reasonable acknowledgment.
Although it's hard to say for sure, we know the risk is much less if you eat wild salmon
Summary: Farmed salmon contain high contaminants such as PCBs, but the dose varies between fish from different regions.
Mercury and other metals in salmon
Current evidence of trace metals in salmon is contradictory.
Two studies show little difference in mercury between wild salmon and salmon .
However, a study showed that wild salmon has a level of 3 times higher .
Arsenic concentrations are higher in farmed salmon, but the content of cobalt, copper and cocoa is higher in wild salmon .
However, the trace metals in both salmon are also found in a low amount so it does not seem to be ominous.
Summary: For an average person, trace metals in salmon do not seem to be found with harmful amounts. This is true for both salmon and wild salmon.
Is wild salmon worth adding cost and inconvenience?
It is important to note that farmed salmon is still very healthy.
Farmed salmon tend to be much larger and contain higher amounts of Omega-3.
Wild salmon is also much more expensive than farmed salmon and may not be worth more money for some people. Depending on some things that approach wild salmon may not be convenient (or impossible).
However, due to dietary differences, farmed salmon is more likely to contain harmful contaminants than wild salmon.
While these contaminants appear to be safe for normal people to consume moderate amounts, some experts recommend that children and pregnant women only eat wild salmon, just to be safe.
How to process the salmon is still good for health
It is best to eat fatty fish such as salmon once or twice a week for optimal health.
The only real concern for farmed salmon is organic pollutants such as PCBs. If this is what you care about, research a little bit about the origin of the salmon and choose one that is not grown in polluted water.
With large amounts of Omega-3, the protein High quality and beneficial nutrients, I believe that the benefits of eating salmon (whether breeding or wild) far outweigh the negative for most people.
I personally eat salmon every week, and I'm not worried at all. I will choose wild if possible, but unfortunately it is not available to me right now.
If wild salmon is accessible to you, then it is a better choice. But farmed salmon is still healthy, only slightly "less healthy" than wild salmon.