Krill (Euphausia superba) is a tiny crustacean that is found in cold waters of the ocean (e.g. Antarctic). Krill are at the bottom of the food chain, serving as a food source for a variety of other fish and sea creatures including: whales, penguins, squid, and seals. In recent years, supplement companies have begun harvesting krill for their “oil.”
Marketers are attempting to convince people taking fish oil that krill oil is a superior source of omega-3 fatty acids (DHA and EPA). There are numerous speculative krill oil benefits, but currently there is insufficient data to leap to the conclusion that in the battle of krill oil vs. fish oil, that krill is a superior option. With a widespread increase in krill oil supplementation, people have questioned whether taking krill oil frequently could be dangerous.
Krill Oil Dangers: List Of Possibilities
Since krill oil is a relatively new substance and benefits of its supplementation are scientifically unclear, many websites attempt to highlight its potential dangers. Understand that a majority of information online is opinionated and motivated by marketing, not science. The only possibilities of “dangers” associated with krill oil stem from: product impurities, improper dosing, allergies, and drug interactions.
When purchasing any supplement, it is highly important to purchase quality over quantity. Taking a krill oil that has impurities and/or is contaminated with heavy metals is going to do more harm than good. Some research has shown that Antarctic krill are susceptible to accumulating “intermediate” amounts of contaminants.
Fortunately the United States FDA has accepted notices from krill manufacturers mandating that all krill oil products should meet GRAS (Generally Recognized as Safe) status before they are sold. The FDA has not tested krill products and unfortunately there’s not enough data out to conclude which company makes the “purest” product.
Dioxins & PCBs: Most krill oil supplements contain little to no dioxins and PCBs. Krill is a small creature with a short lifespan at the bottom of the food chain. In comparison to fish (e.g. tuna) that live for many years, are more massive, and that may eat other fish, the krill don’t generally accumulate many dioxins and PCBs. Big fish tend to accumulate significantly more toxins than smaller sea creatures like krill (which feed on algae).
The way a company processes their krill can also mitigate risk of contamination from PCBs. Most reliable krill oil suppliers frequently test their product for contaminants to ensure safety of the consumer. The USDA has set a threshold at a maximum of 2 ppm (parts per million) of PCBs in fish. In most krill oil supplements, the amount of PCBs is so minimal, that it’s nearly undetectable.
Expiration: When purchasing any supplement, it is important to carefully take note of any listed expiration date. To avoid the dangers of rancidity, make sure the krill you purchase is not nearing (or past) the expiration date. Also carefully examine the packaging to make sure that the krill oil hasn’t been tampered and/or subject to a leak. Any leaks, broken seals, or sunlight exposure could result in quicker oxidation.
Heavy metals: It is important to realize that the krill you’re taking could be laden with various heavy metals (lead, mercury, arsenic, etc.). To protect consumers, most companies set strict standards in assessment of heavy metal toxicity within their krill oil. Most standards in regards to metal toxicity are set by the World Health Organization (WHO) as well as the Environmental Protection Agency (EPA).
They investigate the krill oil supplements to determine how many parts per million of heavy metals is safe for human consumption. You’ve likely heard of various seafood products and fish oils containing “mercury.” Even if you eat fish a lot, you’re likely to have consumed some mercury. The buildup of mercury and dioxins are thought to primarily stem from fuel emissions, coal-burning, and mining.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/25170991
Microbial testing: Most supplement companies test for various microbes to ensure that there is no salmonella, E. Coli, staphylococcus or other harmful bacteria within their product. They’ll also test for yeast, mold, and water before considering their product safe for a consumer. Most krill oil supplements will have been manufactured in a safe environment without exposure to toxins or other contaminants.
When you remove a krill oil capsule from the bottle, you are actually contaminating it more by touching it than it originally was. To prevent the possibility of contamination via touch or exposure to your environment, some companies manufacture krill oil in “blister” packaging that separates each individual capsule from the others.
Oxidation: Omega-3 fatty acids found within krill oil are susceptible to oxidation. In other words, when the supplements come in contact with oxygen, they lose electrons, leading to rancidity. With fish oil (particularly if stored improperly), rancidity can commonly occur.
However, with krill oil, the danger of oxidation is less likely because it contains an antioxidant known as “astaxanthin.” This antioxidant prevents the oxidation process from ensuing even at room temperature. Many forms of krill oil also contain Vitamin E, which further inhibits oxidation. It is speculated that the amount of astaxanthin (mg) influences the oxidation propensity; brands with reduced quantities may be more subject to oxidation.
Rancidity testing: Most companies will test their krill oil for rancidity before it is shipped out to consumers. The Global Organization for EPA and DHA Omega-3 (GOED) has set standards by which krill oil manufacturers must follow. The rancidity level is measured and a number is stated as a value called “TOTOX.” In brief, TOTOX levels are indicative of marine oil freshness.
Some companies also test for peroxide and anisidine levels prior to adding flavoring and/or encapsulating the krill oil. The best companies will take things a step further by repeating these tests after final processing to confirm that no oxidation has occurred during the encapsulation that may minimize the oil quality. The “TOTOX” score must be no greater than 26 to ensure safety of the consumer; most companies test significantly below this.
Note: All krill oil supplement companies should have a “Certificate of Analysis” as proof of product purity and accuracy.
Taking excessive amounts of krill oil could result in some adverse effects such as blood thinning. Therefore, it is recommended to consult your doctor if you are unsure about the dose that you’re taking. Follow instructions on the bottle of your krill oil and listen to advice given from medical professionals. Taking too much of any supplement could result in dangerous effects.
Danger could result from taking krill oil if you are taking certain medications. Those that are taking: aspirin, blood thinner drugs (e.g. Warfarin), beta-blockers, estrogens, and diuretics – should consult a medical professional before considering krill oil. If you are on any medication and have a question as to whether it could have a detrimental reaction with krill oil, always talk to your doctor.
While most people do not notice interaction effects, it is important to realize that high doses of krill oil can result in blood thinning effects. If you are already taking a blood thinner, you could be compromising your health. Keep in mind that not all interactions have been medically documented and that if you suspect krill oil interacting with another drug, the krill should be discontinued.
4. Seafood allergies
Krill oil is not recommended to be utilized by people with allergies to seafood. If you are known to have a fish or shrimp allergy, it is recommended to avoid taking krill oil. These allergies can result in an array of symptoms including: diarrhea, vomiting, stomach cramps, pulse changes, shortness of breath, etc.
In some cases the allergy could be life-threatening, therefore it is important to proceed with caution and consult a medical professional (if you suspect a seafood allergy) before taking krill.
5. Environmental impact
Some critics of krill oil claim that its harvesting will yield detrimental effects throughout the food chain. Krill is considered a foundational link in the food-chain, and makes up the world’s largest biomass. Increased harvesting of krill could have an impact on the survival of the species and larger fish (e.g. whales) that rely on krill as a staple food supply.
It is important to consider whether companies are utilizing sustainable harvesting practices. Sustainable harvesting ensures that krill populations are regenerated and/or replenished. That said, current harvesting rates are unlikely to affect the krill population anytime soon. Krill for human consumption accounts for less than 1% of the total harvest; most is for livestock feed and pet food. There’s no major problem with harvesting krill as its supply is abundant.
Is krill oil dangerous? Unlikely.
While it is important to always be skeptical of marketing that makes krill oil seem perfectly safe, most of the safety claims are accurate. The potential danger associated with taking krill oil should be considered minimal. In fact, krill oil is likely less susceptible to oxidation, rancidity, and accumulation of toxins compared to fish oil.
The only time to be a little worried about krill oil is: if you take too much of it, have some sort of allergic reaction, suspect that it may be interacting with other medications, or you are taking a batch that has already expired. Most dangers linked to krill oil are from people taking it along with anticoagulants; this can be problematic in that too much blood thinning occurs. You also may not want to take krill oil if you are pregnant just for added precaution.
Understand that humans did not evolve to pop krill oil supplements, therefore if you notice any problems, it’s probably smart to simply stop taking it. Purchase your krill oil from a reliable company (make sure their supplements are “certified”) and look for high amounts of astaxanthin (to prevent oxidation). Finally, store your krill at room temperature (don’t put it in the fridge) and use before the expiration date. If you follow the tips in this article, you should be less susceptible to any potential dangers.