Is Krill Oil Really Better Than Fish Oil?

I recently received an email from a subscriber asking about krill oil. This is such an important topic that I wanted to tell you my thoughts on it.

As you may know, one of the best supplements you can take is fish oil. That’s because it contains the critical oils EPA and DHA. And most of us cannot make enough of these oils. The body uses EPA as an important part of reducing inflammation. And DHA is food for the brain and nerve cells.

So what about krill oil? It also contains EPA and DHA. And there has been a very significant marketing blitz the last few years insisting that krill is a better choice for EPA and DHA than fish oil.

But is that true?

Before I get into the answer to this question, let me explain what krill oil is. Krill are tiny shrimp-like creatures that live in the ocean. They are a major source of food for a number of fish and other aquatic animals, including whales. Fish and whales love krill, and to a large extent their ability to survive depends on having enough krill available. But humans and other land- based mammals have never eaten krill. The way we get the EPA and DHA that’s contained in krill is by eating the fish that feed on the krill or by taking fish oil supplements. Ok, now that you have that straight let’s have some fun.

Several years ago, I started testing the EPA, DHA, and Omega-3 Index blood levels in all my patients. I do it using a laboratory called OmegaQuant. You can do the same thing at home. Just go to www.omegaquant.com and order the $49.99 test. You will get back your EPA and DHA levels as well as your Omega-3 Index. People all over the world use the Omega-3 Index to determine whether or not people have adequate amounts of EPA and DHA in their bodies. An optimal Omega-3 Index is 8% or greater. Levels below 5% are associated with disease. With all this testing, here’s what I’ve learned.

Whenever I saw an Omega-3 Index that was below 5%, I could bet on one of two things. Either one, the patient was not supplementing his diet with fish oil. Or two, he was taking krill oil. In short, after doing literally hundreds of these tests, I never found one person who was taking krill oil and had an Omega-3 Index anywhere close to optimal. But why? Why does krill oil perform so badly? Time to hit the books.

First of all, the various suppliers of krill oil all make the argument that krill oil is a superior form of EPA and DHA. They make this claim because the EPA and DHA that are in krill oil are different than the EPA and DHA in fish oil. In fish oil, the EPA and DHA are found in the triglyceride form. In krill oil, the EPA and DHA are in the phospholipid form. Proponents of krill argue that since the phospholipid form is the form that’s used in cell membranes, krill oil must be better. But this makes no sense at all. Think about it.

In the entire history of the world, human beings have never consumed krill. So how is it possible that we require EPA and DHA from krill? Genetically, humans are designed to ingest EPA and DHA in the triglyceride form contained in wild animals and fish, not the phospholipid form found in krill. To infer that humans need the phospholipids from krill is scientifically absurd. But what about bio-availability? Krill proponents often make the unsupported statement that since krill has EPA and DHA in a phospholipid form, it’s much more bio-available.

The term bio-available refers to how efficiently our bodies use a natural substance. So to say that krill oil is more bio-available than fish oil is to say that it works better in the human body. So what’s the truth? A study just published a few years ago is the only study I know of that looked at this issue directly. In that study, the researchers recruited 12 healthy young men and gave each of them enough fish oil to contain 1,680 mg of EPA+DHA. They measured their plasma phospholipid levels before and at 2, 4, 6, 8, 24, 48, and 72 hours after they took the supplements. Then they repeated the experiment using enough krill oil to contain the same amount of EPA+DHA. As I will explain below, that meant that they had to give the men a little more than three times as many capsules of the krill oil. What happened?

Even though the EPA and DHA in the krill oil were in the phospholipid form and the EPA and DHA in the fish oil was in the triglyceride form, the blood phospholipid levels were no different. There was no evidence at all of superior bio-availability or absorption. That’s because the liver is able to convert the triglyceride forms into the phospholipid forms. And they also found out something else that was very interesting. Although the purveyors of krill oil tout the fact that it contains EPA and DHA as phospholipids, the researchers discovered that this was only true for 80% of the oil. The rest of the EPA and DHA were not in the form of phospholipids.

So there doesn’t seem to be any better bio-availability of krill oil over fish oil. But what about the effects of the different oils on metabolic functions like cholesterol or triglyceride synthesis, oxidative stress, or inflammation? Maybe krill oil excels there? To find the answer to this question, researchers looked at 113 men and women with normal or elevated cholesterol and/or triglyceride levels. They gave some of them six capsules of krill oil every day for seven weeks. They gave another group three capsules of fish oil. Here’s what they found out.

First of all, in the author’s words, “…there were no significant differences in the changes in any of the omega-3 levels between the fish oil and the krill oil groups.” In addition, they observed “no statistically significant differences in changes in any of the serum lipids or the markers of oxidative stress and inflammation between the study groups....” So much for the idea that somehow the EPA and DHA in krill oil have magical effects that the EPA and DHA in fish oil don’t have. They both do the same thing. The only difference is that you just have to spend more money and take more capsules of the krill oil. This brings me to the next difference between fish oil and krill oil – numbers.

Perhaps the most significant scientific differences between fish oil and krill oil simply have to do with numbers. There are more than three thousand studies documenting the effectiveness of fish oils on a wide variety of diseases and health problems. However, there is only a handful exploring the use of krill. Krill oil may be effective, but there’s certainly not much proof that it is. And that’s not the only number that’s important when it comes to the fish oil/krill oil debate. The other numbers have to do with capsules and dollars.

Perhaps the biggest reason for the failure of krill oil to maintain a healthy Omega-3 Index has to do with the low content of both EPA and DHA that’s in krill. Krill oil has less than one-third as much EPA and DHA than fish oil. And that’s the content of the best and most expensive brand. Other less expensive brands have less than 25% of the content found in fish oil. That means that in order to get the required amount of EPA and DHA, you would have to take six to nine capsules a day of krill. That amounts to $3-5 per day. Probably more than most people want to pay for a supplement.

Next, is the issue of the environment. Although it makes no sense, the krill oil purveyors insist that harvesting krill is much more planet friendly than harvesting fish. But it’s an undisputed fact that krill is the foundation of the food chain for many oceanic species. Commercial krill harvesting has already been banned in several major oceans and the implications of over- harvesting krill are devastating. Some experts have even gone on record saying that harvesting krill is an ecological disaster waiting to happen. Compare this to fish oil supplements.

The fish oil industry has been around for decades and is very tightly regulated. Also, only a very small proportion of the current anchovy, sardine, and mackerel harvest goes toward fish oil for humans. The vast majority of the harvest has been for pet food, fertilizers and other non-human use. Without increasing the harvest at all, there’s still a huge potential to increase the production of fish oil for human consumption. The krill oil environmental superiority myth is not based on reality.

Finally, I want to deal with the antioxidant issue. Krill marketers insist that krill oil is superior to fish oil because it contains antioxidants. It’s true. Krill oil does contain antioxidants, while fish oil does not. But once again, there’s a problem with the numbers. The amount of antioxidants in krill oil is so low that its effect on the human diet is close to negligible.

If you’re still a fan of krill oil after reading this article, then let me make a suggestion. Test yourself. Go to www.omegaquant.com and order the $49.99 test of your Omega-3 Index. If it’s over 8%, please let me know. As I said before, I’ve never seen that happen. If it’s not, continue to increase the dose until you get a healthy index. You will probably need in the order of six capsules (or more) every day to do that.

Yours for better health,

Frank Shallenberger, MD