How Do You Know if Your Fish Oil Supplement is Rancid, Spoiled or Contaminated?

Fish Oil Supplements

A test was conducted by an independent testing agency, namely, Consumers Labs (CL) regarding 54 fish oil products and as far as purity goes, all supplements were found to contain at least trace levels of PCBs, and some had lead. However, all products, except one, did not exceed contamination "limits" set by the EPA. Therefore, if a fish oil supplement claims to be "free of," "void of," or have "no detectable PCBs," they might not be being truthful. 

None of the products tested by CL contained mercury levels over 10 ppb (parts per billion). By comparison, levels in fish range from 10 to 1,000 ppb, depending on the type.

 A common complaint of fish oil supplementation  is "fish burps" which occurs when you experience fishy reflux after taking certain fish oil supplements. Fish oil supplements that come back up on you are often spoiled, or rancid. While spoilage does not necessarily indicate lower amounts of omega-3s, it does indicate that the oils have gone from being healthful to being potentially harmful. Rancid, spoiled oils contain oxidized fats, called lipid peroxides.

The measurement of rancidity/spoilage is called the TOTOX value, meaning Total Oxidative value, and evaluates the content of peroxides. Rancid oils have high TOTOX values and high amounts of lipid peroxides. These oxidized fats (peroxides) start free radical cascades (the pathways of aging and disease) that can damage the fat containing membranes of your cells. They also deplete your body's stores of antioxidants, because this is how your body tries to defend itself from the free radicals.

Another problem identified by Consumer Labs in its investigation of fish oil supplements, is that some companies do not contain the amount of EPA and DHA stated on the label. This is also the case with other types of dietary supplements, and fish oils are not immune to this problem.

Concentrations of EPA and DHA in fish oil can vary as much as tenfold - from as little as 8% to 80% of the fish oil content. Concentration depends on what fish the oil came from, how the oil from the fish was processed, and other ingredients added to the product.

Also problematic were certain claims on supplements, which are not FDA-defined terms and, therefore, not regulated. Also, "Tested in FDA Approved Laboratories" is false, because the FDA does not approve any analytical labs, so these claims are not correct.

Some people think that if a little bit is good more is better; but that is not the case, especially with fish oils. Fish oils containing omega-3 fatty acids, work in the body like blood thinners and blood pressure reducers. They're also polyunsaturated fats, which are highly unstable and susceptible to oxidation.

Adults (usually those over 40) often make the mistake of taking too much fish oil along with blood thinners such as aspirin, or sometimes prescription thinners, like Coumadin. In these people, even the slightest cut can result in a bleeding event that takes several minutes to clot. In worse cases, internal bleeding can occur. Or, they take too much fish oil and end up with drastically low blood.

Excessive fish oil also may raise your blood level of polyunsaturates so high, that your cells become extremely susceptible to free radical damage. You see, your cell membranes need to contain a certain balance of unsaturated and saturated fatty acids for them to resist attack from dangerous free radicals. If your cells are mostly unsaturated from taking high doses of fish oil, you increase the chance that they can become damaged from oxidative stress, which increases your likelihood of cancer. One way to combat this pro-oxidative state is by taking very high doses of anti-oxidants, but a smarter move would be to take less fish oil.

According to omega-3 fatty acid experts, healthy individuals need only take up to 1 gram of EPA + DHA (combined) per day to achieve the multitude of health benefits. Individuals with heart disease, cognitive decline, or who consume a higher-fat diet, may benefit from additional doses of omega-3s.



Krill is the primary food source for certain whales;
only a small percentage of total krill biomass
is being harvested for human use.

Another way to get good doses of EPA and DHA is with krill oil. Krill oil comes from krill, which are tiny shrimp-like creatures that make up the lion's share of the oceanic biomass. 

The shrimp like krill may only be a couple of inches long, but they make up for it in numbers. So large is their collective weight, or "biomass," that it's measured in the billions of tons.
The EPA and DHA in krill oil are shown to be just as effective as those in fish oil - even despite the fact that krill oil contains less total EPA and DHA per gram.

Despite the term "krill oil," krill aren't oily at all, consisting of over 65% protein. The small amount of fat they do carry on their tiny lean frames is approximately 20% omega-3s, including plenty of EPA and DHA.  Another attractive feature with krill is their natural content of powerful antioxidants such as the carotenoid, astaxanthin, which is responsible for also giving salmon its bright red color.

Astaxanthin is a powerful antioxidant that is more effective than other natural antioxidants like beta-carotene, alpha-tocopherol, lycopene and lutein, which makes it even more beneficial for fighting diseases influenced by oxidative damage, like diabetes and heart disease.

Krill Are More Eco-Friendly
Since krill are quite low on the food chain compared to most other fish and seafood, they contain fewer environmental toxins. This means less risk of mercury, PCBs, dioxins, and other chemicals related to nervous system disorders, cancer and other diseases.

Their large biomass, furthermore, means that they can be harvested fairly easily with lower risk of depleting their populations. From this perspective, you could argue that the use of krill supplements is more "eco-friendly." An argument against krill use for their oil is that they're the primary food source for certain whales, seals, penguins, and other animals. Its harvesting has been a subject of environmental debate.   

In defense, the krill population is plentiful and only a small percentage of total krill biomass is being harvested, most of which is used in fish meal and not for direct human consumption. There are also catch limits for sustainable exploitation established by a conservation commission known as CCAMLR, and registration and monitoring is required of harvesting vessels. According to the CCAMLR, only 18% or less of the current krill allowable catch limit is used today. If the krill allowable catch reaches a certain threshold, all fishing must stop until the catch is reallocated. 

Also, only 2% of the total global catch of krill oil is used for supplements - the remaining 88% goes to feeding fish and fishing.

Excerpts from: What Your Doctor Never Told You About Fish Oil, Cassandra Forsythe-Pribanic, PhD, RD, CSCS, and Jayson Hunter, RD, CSCS