Wild salmon, particularly the sockeye, has a high concentration of astaxanthin, as a result of consuming planktons and algae. In the contrast, salmons raised at farms feeds on food pellets, which contain only the synthetic version of asthaxanthin. The synthetic asthaxanthin is derived from petrochemicals, and is very different from the natural version .
Farmed salmon also consumes fodder that can put you in danger of dioxin and mercury poisoning. As a result of this discovery, some salmon farmers have tried to replace the artificial fodder with corn and soy protein, thus avoiding the contamination. However, since the fish don’t like eating soy and corn, the quality of this meat is very low. To compensate for that, farmers use antibiotics which keep the fish healthy, but these antibiotics end up in our bodies when we consume them. The vegetable oils found in this food also have negative effect on the omega-3 fatty acids found in salmon meat, and can infect them with mold toxins.
According to FDA and EPA who have both studied the mercury content in fish, the meat of wild salmon does not contain any mercury traces. Having all this in mind you should avoid eating farmed salmon, and stick to the wild-caught. They’re good source of nutrients, and should be found at your table as often as possible. There are several varieties to choose from at the market. Each has a specific taste, so find which one suits you the best.
Sockeye salmon is one of the safest choices at the market, because it’s difficult to farm it as a result of its unique eating habits. Because it primarily feeds on planktons it has a high concentration of good cholesterol, vitamin D and astaxanthin. It also abounds in omega-3 acids and has a strong flavor. It’s especially tasty when smoked.
Chinook salmon (king salmon) has the highest concentration of omega-3 acids, measuring almost three times more than the other varieties. This is a consequence of living in deep, cold waters. Namely, the omega-3 fats keeps them warm, protecting them from freezing. Unlike the previous species, this variety of salmon can be farmed. That is why you should be careful when buying it.
Pacific coho salmon is extremely rich in vitamin D, with good concentration of omega-3 acids.