Mercury levels and polychlorinated biphenyls (PCBs) are a major concern in the case of oily fish. It is important that we choose an oil that meets international standards for heavy metals, PCBs, dioxins and other contaminants.

Dioxins, furans and PCBs are organic pollutants from industrial processes. They are found in small quantities in virtually every medium (including soil, water and food) worldwide. Consuming these substances above the safe levels  may increase the risk of developing cancer over a lifetime.

The most efficient and best method of purifying fish oil is molecular distillation.

Omega-3 fish oils are prone to oxidation. which causes rancidity. Rancid oils are pro-inflammatory and therefore contribute to disease, rather than prevent it. It is important that we choose a stable fish oil which will be odorless and have no fishy taste or smell.

In order to achieve the desired health effect, fish oil must contain sufficient amounts of long-chain omega-3s, EPA and DHA. Many fish oils (and krill oils) contain little EPA and DHA, and you need to take many capsules to achieve the desired effect.

Daily Amounts Required for Accepted Health Benefits:

• for maintenance of normal heart function: 250 mg EPA + DHA
• for maintenance of normal brain function: 250 mg DHA
• for maintenance of normal vision: 250 mg DHA

It is the manufacturer’s responsibility to display the amount of Omega-3, EPA, DHA, and antioxidants in the oil. A number of products contain 1000 mg of Omega-3, but the DHA / EPA ratio is only 12/18%.

Preferably,  fish oil should also contains an antioxidant (ex. Vitamin E) to stabilize it and prevent it from oxidation.

The ability to absorb the beneficial components of fish oil is based on its form. The more natural the structure, and the less it has been chemically altered, the better. There are currently 3 forms of fish oils on the market

• Natural Triglyceride Oil : The oil as you would obtain if you squeeze the fish and extract the natural oil directly. This form is highly bioavailable.
• Ethyl Ester Oil: Chemically modified to achieve higher levels of EPA and DHA. Bio-availability of chemically modified oils is lower than natural triglyceride oils.
• Synthetic Triglyceride Oil: Natural triglycerides are converted to ethyl esters for concentration, then re-converted into synthetic triglycerides. The original position of the triglyceride’s carbon bonds change and the molecule’s overall structure is altered, which impacts the bioavailability of the oil.

Given the very high demand for fish oil, it is important that producers apply sustainable fishing practices to protect their future supplies.

Does your fish oil have a sustainability certificate from an international body: Friend of the Sea, Marine Stewardship Council (MSC)?

Quantity:

• Are you getting the quality EPA and DHA needed for the beneficial effects?

Quality:

• What is the technology of manufacturing the oil ( molecular distillation would be desirable)?
• Does the oil contain an antioxidant (in most cases vitamin E) that protects it from oxidation and stabilizes it?
• Certificate: Does the oil have a widely recognized international certificate (ex. IFOS = International Fish Oil Standards Program)?