They claim that this purification method requires the use of heat, which reduces the omega-3 content. The truth is that molecular distillation is accomplished using vacuums and that vaporize the oils using pressure, rather than heat. Choosing Natural Fish Oil Supplements Before you buy natural fish oil, there are some things that you need to consider.

Mercury, lead, cadmium, PCBs and dioxins are a few that we have to be concerned about, even when we are eating fish. Rather than reducing the omega 3 content, the end product is actually more concentrated. According to the Environmental Defense Fund, we should never eat or buy.

Thankfully, scientists have not learned to produce them synthetically, yet. But, there are some safety issues that are of concern, if the manufacturer does not purify the oils properly. From a basic standpoint, all fish oils are naturally occurring. There are several companies claiming that their products are better and more potent because they do not use molecular distillation.

Distillation is necessary because of pollutants and toxins that are present in the water, and thus end up in the fish.