Health Benefits of Krill Oil

According to Dr. Mercola, krill oil may be effective and benefit as many as 20+ medical conditions.

These conditions include1:

  • Cardiovascular disease
  • Osteoarthritis and rheumatoid arthritis
  • Brain disease, cognitive dysfunction, memory loss, brain aging, learning disorders and ADHD
  • Inflammation
  • Metabolic syndrome, including fatty liver and obesity
  • Cancer
  • Premenstrual syndrome
  • Kidney disease
  • Cataracts and macular degeneration
  • Lowers cholesterol, raises HDL cholesterol (the good, protective cholesterol) and lower triglycerides

Krill Oil v Fish Oil

Both krill and fish oil are great natural sources of omega-3 fatty acids, which are essential to good health. While it is true that omega-3 can also be obtained from plants like chia seed, hemp and flaxseed, we actually require both DHA and EPA and that is only readily available from animal products. That means you do need to eat oily fish like salmon and sardines, and/or take omega-3 supplements like krill oil or fish oil.

However, there are problems with fish oil that you should know about.

The first problem is the way fish oil is extracted. The process often requires solvents which is never a good thing, and during the extraction, fish oil comes into oxygen in the air which causes it to oxidise.

Another problem with fish oil is heavy metal toxins. The sea is awash with heavy metals, and the further up the food chain an animal is, and the older the fish is, the more heavy metals their bodies will contain, including harmful metals like mercury, lead, cadmium, etc.

This means the fish used to extract fish oil are potentially concentrated sources of heavy metals, which can get into the oil unless you are buying a top brand of fish oil. Look out for the labels on these products to make sure they are relatively free of toxic metals. Price is actually a good indicator of quality in this case. Fish oil should also be protected from light, so if you are buying clear plastic or glass bottles, the oil will spoil.

If you want to buy fish oil, choose:

  • Smaller containers
  • Dark bottles that do not allow light through
  • Higher price usually indicates quality, as more expensive oils are priced higher because of the extra costs of purification.
  • Buy from a company with a high turn-over and can ship overnight to ensure the oil is fresh.
  • Always store in the refrigerator (fish or krill oil).

The lower down the food chain, and the shorter the lifespan, the less heavy metals are present in the organism. Krill is right at the bottom of the food chain, so is about as pure as you can possibly get. Not to mention the fact that krill are harvested in the Antarctic which has purer water to begin with.

Krill is the world's most abundant biomass available, and with less than 2% harvested, it is an easily sustainable source of omega-3 supplements. Compare that to the sustainability of fish. The ocean's fish simply are not sustainable, meaning we rely far more on farmed fish. However, farmed fish are actually fed other fish (that ‘s what fish food is made of), and by feeding the fish with other fish, heavy metal toxins accumulate in the farmed fish as well. Krill can also be used to feed farmed fish, but due to the economics of this, fish food producers prefer to use fish for their feed – it's more profitable.

Krill Oil Contains:


Omega-3 is a polyunsaturated essential fatty acid. That means it cannot be made in the body, so has to be supplied in the diet. The problem is, most of us get nowhere near enough of this nutrient in the diet, so should supplement with a quality

Omega-3 fats have been shown to play an important role in brain function, growth, heart health, reducing inflammation, lowering cholesterol & triglycerides and lowering the risks of cancer, arthritis and heart disease2.

With high concentrations of omega-3 in the brain, it appears to be vital for cognitive performance and behaviour.

Omega-3 in krill oil is attached to phopholipids which increases its absorption. Krill oil is an extremely rich source of these essential fatty acids.

In medicine, omega-3 has been used for, or has potential in treating:

  • High cholesterol
  • High blood pressure
  • Heart disease
  • Diabetes
  • Rheumatoid arthritis & osteoporosis
  • Lupus
  • Depression
  • Bipolar disorder
  • Schizophrenia
  • ADHD
  • Cognitive decline
  • skin disorder
  • Inflammatory bowel disease
  • Asthma
  • Macular degeneration
  • Menstrual pain
  • Colon, breast & prostate cancer

Omega-3 deficiency often has the following symptoms: fatigue, poor memory, dry skin, mood swings, depression and poor circulation. During pregnancy, if the foetus is not getting enough omega-3 from the mother, there can be vision and nerve problems in the child.

A note about Omega-6

Omega-6 is not the same as omega-3. Omega-3 helps reduce inflammation while omega-6 increases inflammation. However, omega-6 is still important for our biochemistry. The ideal ratio of omega-6 to omega-3 in our bodies is 1:1, yet most of us consume far higher levels of omega-6, especially in vegetable oils, so our actual ratio may be 20:1, 30:1 or higher.


Astaxanthin is a powerful antioxidant that is important for heart health. Outside of krill oil, astaxanthin is very unstable. In krill oil, astaxanthin is incredibly stable. Krill oil contains up to 50 times more astaxanthin than fish oil.

Astaxanthin will help protect your cell membranes from free radical damage, and can also filter to the harmful UVA rays (which destroy vitamin D) from the sun without affecting UVB which your body uses to make vitamin D.

Astaxanthin is red, so it should come as no surprise that quality krill oil is a deep red colour.

EPA and DHA phopholipids

As mentioned earlier in this article, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found in cold-water, oily fish like salmon, mackerel, herring and tuna.

DHA is important in the normal functioning of your nervous system, and offers anti-inflammatory properties. It's associated with mood improvements and insulin sensitivity, muscular development and sleep3. If you body is functioning correctly, it can also convert EPA into DHA.

Krill is an excellent source of DHA and EPA because they are packaged into phospholipids which make them more easily absorbed and assimilated by the body (cell membranes around the cells in our body is made up of a phospholipid bilayer). In fish oil, these fatty acids come as triglycerides that require processing by the body before they can be used.

While DHA and EPA are animal-based omega-3 fatty acids, plants contain their own, called Alpha-Linolenic Acid (ALA). ALA can be converted into DHA but it is not very efficient, so you really do need animal sources of omega-3s.

Side Effects

Published studies on the side effects of krill oil are few and far between.

Krill oil may cause similar side-effects to fish oil. One of it's properties may well lead to certain side-effects in some individuals, and that's it's ability to thin blood. It is recommended that you stop taking krill oil two weeks before you have an operation.  It may also cause bleeding gums or nosebleeds.  If you have any more serious side-effects, stop taking krill oil and consult your doctor.

The FDA?

To my knowledge, the FDA has not made any recommendations on the safety of krill oil.  Since it is a dietary supplement, it does not require a prescription to buy.  It is worth noting that the FDA have issued warnings about the levels of methyl-mercury in some fish, like tuna, swordfish and marlin, and therefore suggest limiting this type of fresh fish in pregnant women and children4.


Categorized as Blog

By Andy

Hi, my name is Dr. Andy Williams and I am a biologist with a keen interest in diet and nutrition. This site was set up to help me explore the research, facts and fiction about Krill Oil. Please feel free to contact me if you have any comments, questions or suggestions.

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