A group of toxins, known as persistent organic pollutants (POPs), are present throughout the environment. They come mainly from pesticides, industrial chemicals, pharmaceuticals and industrial waste.
Avoiding them completely is impossible. They are even found in remote areas like the arctic. The best we can do is reduce our exposure to them.
Our main exposure is through food. Fortunately, wise food selection can make a huge difference.
These toxins bioaccumulate, which means increasingly greater levels are found as we move up the food chain. Plants have the lowest concentrations and some fish and fish oils the highest. Once ingested by animals these toxins are off loaded into their fat and milk, so these products are the most contaminated. Fish and animal livers have high concentrations too.
A further complication is animal feed. What an animal was feed is not shown on food labels. For example, in Sweden, fish from the Baltic sea must be sold with a health warning. However no warning is required to sell fish from another region that have been fed polluted fish from the Baltic sea. This problem has spread as far as Australia.
The World Health Organisation tested foods for polychlorinated biphenyls (PCBs), a subgroup of POPs. The wide range of toxin levels can be seen in this list :
• Animal fat: 20 to 240 μg/kg
• Cow’s milk: 5 to 200 μg/kg
• Butter: 30 to 80 μg/kg
• Fish: 10 to 500 μg/kg, on a fat basis. Certain fish species (eel) and fish products (fish liver and fish oils) may contain much higher levels, up to 10,000 μg/kg
• Vegetables, cereals, fruits, and a number of other products: <10 μg/kg
Given the limits of labelling it is impossible to know the level of pollution in food sold. All we know is that some of the fish and fish oil products tested above contained 50 times as much of these toxins as the most polluted grains and vegetables.
POP exposure can cause developmental defects and chronic illnesses. Some are carcinogens and some endocrine disruptors affecting the reproductive system, central nervous system, and immune system. According to the World Health Organisation, 90% of human exposure, to dioxins, a subgroup of POPs, is through food, mainly meat and dairy products, fish and shellfish.
Avoiding these toxins is important for pregnant women and children. Low-level exposures have been linked to low birth weights and neuro-developmental effects in children.
If you are looking for a dose of omega 3 oil, one option is algae-based omega 3 oil. This contain the longer chain DHA and EPA omega 3 oils contained in fish oil as opposed to the shorter chain ALA omega 3 oil found in plants.