Purity

Because we are concerned that drinking water is not pure enough, Americans spend millions of dollars on bottled water. We know that water drawn from a local lake that is not pristine is not ideal to drink no matter how many times it’s run through a treatment plant.

Fish oils are the same. No matter how well they are distilled, the significant factors in purity are

what fish is in the oil and
where the fish come from.

What fish is in the oil

Sardines and anchovies are ideal for providing pure fish oils because they are low on the food chain. Every time a fish eats another fish, it concentrates within its body the heavy metals and pesticides from the fish it consumed. Because salmon are high up on the food chain, they contain more contaminants than sardines and anchovies.

Where the fish came from
Waters the fish live in are another significant factor in purity. Farmed fish do not live in pristine waters; they live in crowded ponds and are fed antibiotics and grain-based fish pellets. Studies show that farmed fish, including farmed salmon, contain high levels of contaminants. On the other hand, wild-caught fish from cold waters away from population centers are exposed to fewer environmental contaminants. They also contain higher levels of Omega 3 fatty acids because they eat algae or other fish rather than grain-based pellets. Fish from clean northern waters are the best.