Are there benefits to taking krill oil?

Manufacturers make krill oil from small, shrimp-like creatures called Antarctic krill. The oil is rich in omega-3 fatty acids.

Omega-3s are important for the functioning of our cells, for growth, and for the production of key hormones.

Like fish oil, krill oil contains omega-3s called eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

The best way to get EPA and DHA is by eating enough fish and seafood. These foods also contain other important nutrients, and there’s lots of evidence that they can improve your heart health.

Still, some people may benefit from taking supplements like krill oil. Fish oil supplements tend to be a less expensive alternative.

What are omega-3s, and how might they help?

Most of the potential health benefits of krill oil come from the omega-3s it contains. 

Omega-3s are polyunsaturated fatty acids. They’re part of your cell membranes and are important for healthy growth.

You also need them to produce hormones responsible for blood clotting, artery function, and immune system regulation.

As we mentioned, the best way to take in enough omega-3s is by eating enough fish and other seafood. But krill oil, or other omega-3 supplements, may benefit some people. We’ll dig into this a little later on.

It’s worth noting that a 6-ounce serving of wild-caught salmon, weighing around 170 grams, contains almost as much omega-3 as two 1,000-milligram krill oil capsules.

Next, let’s look at some possible health benefits of getting omega-3s from foods or supplements like krill oil.

Heart health 

While research links eating more fish to having better heart health, one large review of studies found little or no evidence that fish oil supplements lower the risk of heart attack or death from heart disease.

Meanwhile, a large clinical trial with more than 8,000 participants found a link between taking 2-g doses of EPA twice a day and having slightly improved heart health outcomes. The participants were also taking cholesterol-lowering medications called statins.

A review of 65 studies found that taking daily fish oil omega-3 supplements appeared to lower triglyceride levels in people with normal and high starting levels of these fats.

And a more recent review found that krill oil supplements were about as good at lowering triglycerides as fish oil. 

However, people with high triglyceride levels may also have an increased risk of a heart disorder called atrial fibrillation if they take omega-3 supplements. Atrial fibrillation can, in turn, increase your risk of stroke.

Krill oil may also have a positive effect on cholesterol levels. 

One review of seven studies found that krill oil lowered levels of “bad” cholesterol. However, these studies didn’t include many participants, so we need more research to back this up.

Finally, krill oil contains an antioxidant called astaxanthin. Some research links it to raised levels of “good” cholesterol. However, studies tend to look at much bigger doses than those you’ll find in krill oil supplements.

Rheumatoid arthritis 

There’s some early evidence that adding omega-3s to your diet may help ease symptoms of rheumatoid arthritis. 

A small study followed 60 female participants with rheumatoid arthritis for 12 weeks. It found that those who took daily omega-3 supplements had less pain and fewer swollen joints than those who didn’t take the supplements. 

At ZOE, we run the largest nutrition science study in the world, and we know how powerful eating the right foods for your body can be. Learn more about how to achieve your best health by taking our free quiz. 

Cognitive health 

Researchers reviewing multiple studies found that eating more omega-3s may improve cognitive functions, like focus and memory, and reduce the risk of Alzheimer’s disease.

Age-related macular degeneration

Age-related macular degeneration is an eye disease that damages the part of your retina responsible for central vision. 

A review of 21 studies found that people who ate more EPA and DHA had a 14% lower risk of developing an early form of age-related macular degeneration. They also had a 29% lower risk of developing a late form of the condition.

Depression 

At least two large-scale studies of people’s eating habits have found links between the intake of omega-3s and the risk of developing depression. But the studies arrived at slightly different results. 

Another study looked at people with overweight or obesity in Spain. It found that those eating a moderate amount of omega-3s had a reduced risk of depression. This wasn’t the case for those who consumed a low or high amount of these acids.

Krill oil vs. fish oil

Krill oil comes from small crustaceans, while fish oil comes from the tissues of fatty fish.

Both contain the omega-3s EPA and DHA. Still, there are differences between these supplements:

• Cost: Krill oil costs more to make than fish oil, so it can be up to 10 times as expensive.  

• Color: Krill oil has a reddish hue, while fish oil is golden.

• Composition: Krill oil contains an antioxidant called astaxanthin, which may have benefits for heart health. Fish oil naturally contains more omega-3s. Still, krill and fish oil supplements tend to have the same amounts. 

• Absorption: Some scientists have suggested that the body can absorb omega-3s from krill more easily. But a review of the research found that krill oil and fish oil supplements had the same effect on levels of fats in blood.

• Taste and smell: Some people get a fishy aftertaste from fish oil. Fewer people report this with krill oil. 

Should I consider taking it?

Generally, regularly eating fish is the best way to get enough omega-3s. But some people may benefit from taking omega-3 supplements.

You might want to think about EPA and DHA supplements if you’re in any of these groups:

• People who are pregnant or breastfeeding: EPA and DHA are vital for the healthy development of babies. If you’re worried about eating fish while pregnant, you may want to talk to a healthcare provider about a supplement instead.

• Older adults: As we mention above, studies suggest that regularly taking omega-3 supplements later in life could help reduce the risk of dementia and other age-related diseases.

• People who don’t eat seafood: A supplement may be the easiest way to get EPA and DHA in this case. Still, having a very healthy plant-based diet is already linked with a lower risk of heart disease, no matter how much EPA and DHA you get.

Dietary sources of omega-3s

Food is generally the best way to get the omega-3s your body needs.

The heart health benefits of eating fish are much clearer than those linked with taking supplements. Plus, both animal and plant sources of omega-3s come with lots of extra nutrients.

Seafood sources of omega-3s

There are no official recommendations about how much EPA and DHA to get every day.

But the Dietary Guidelines for Americans recommend eating 8 oz (around 227 g) of fish or shellfish every week.  

Here are some options that contain omega-3s:

• salmon: 1.8 g of omega-3s per 3-oz serving

• herring: 1.7 g per 3-oz serving

• mackerel: 1 g per 3-oz serving

• rainbow trout: 0.8 g per 3-oz serving 

• oysters: 0.7 g per 3-oz serving

This serving of oysters also contains another type of omega-3: alpha-linolenic acid (ALA).

Plant sources of omega-3

The main omega-3 in plants is ALA. It doesn’t do the same things as EPA and DHA, but it’s also an essential fatty acid with health benefits of its own. 

Experts recommend that adult females get at least 1.1 g of ALA every day and adult males get at least 1.6 g. And if you’re pregnant or breastfeeding, you need more.

The best plant sources of ALA include:

• flaxseed (linseed) oil: 7.3 g of ALA per tablespoon 

• chia seeds: 5 g per 1-oz serving

• walnuts: 2.6 g per 1-oz serving

• flaxseeds (linseeds): 2.4 g per tablespoon

• canola (rapeseed) oil: 1.3 g per tablespoon

• soybean oil: 0.9 g per tablespoon

To start the process of discovering which foods work best for you based on your body’s responses, take our free quiz. 

Risks and side effects

Doctors consider krill oil and other omega-3 supplements to be safe for most people.

These risks include:

• Drug interactions: Omega-3s can interact with blood-thinning medications, such as warfarin, and nonsteroidal anti-inflammatory drugs, such as ibuprofen. This can cause a cut, for example, to take longer to stop bleeding.

• Seafood allergies: It’s not clear yet whether krill or fish oil supplements are safe for people with seafood allergies.

• Atrial fibrillation: People with high triglyceride levels may have a greater likelihood of developing atrial fibrillation, a heart rhythm disorder, if they take omega-3 supplements. This disorder greatly increases your risk of stroke. 

Some people have reported less serious side effects of taking fish oil omega-3 supplements, like:

• an unpleasant aftertaste or “fishy burps”

• bad breath

• bad-smelling sweat

• a headache

• digestive issues, such as nausea and diarrhea

But because krill oil is chemically different to fish oil, it’s not clear whether these apply to it.

Frequently asked questions

Many questions remain, but here’s what we know so far.

First, we should note that most of the existing research has looked at omega-3 supplements in general, not krill oil specifically.

Can krill oil help with hair growth?

Good nutrition is key for healthy hair. And some limited evidence suggests that krill oil could help with hair growth.

It’s worth mentioning that this study used a specific omega-3 supplement, so the results may not apply to krill oil. Also, it was funded by Innéov, a group formed by L’Oréal and Nestlé.

Can krill oil help with weight loss?

A review of research was unable to find any consistent results to suggest that omega-3 supplements could help with weight loss or body fat reduction.

Is krill oil good for the skin?

Initial research suggests that the omega-3s and other nutrients in supplements like krill oil may help improve skin health, reduce skin aging due to sun damage, and help with symptoms like dryness.

However, many of these ideas come from animal studies rather than research involving humans.

Summary

Krill oil is a food supplement rich in the omega-3s EPA and DHA. It’s similar to fish oil but generally more expensive.

There’s good evidence that regularly consuming omega-3s can reduce your triglyceride levels.

But if a person already has high levels, there are risks associated with taking these supplements.

The best way to get omega-3s is from food. But some of us may benefit from taking a supplement.

People who have atrial fibrillation, take certain medications, or have a seafood allergy should speak with a doctor before taking omega-3 supplements.