Krill oil vs fish oil vs algal oil

Unlock the truth about omega-3s! Is krill oil, fish oil, or algal oil the superior choice for your health? Blackmores breaks down the pros and cons to help you decide.

Omega-3 fatty acids, which are often referred to as "healthy fats," are polyunsaturated fats, a type of unsaturated fat that is healthier than saturated fat.

Omega-3s are often recommended for their benefits for heart, joint, and brain health and fighting inflammation. You may usually hear omega-3 and fish in the same sentence because eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential omega-3 fatty acids only found in marine animals. The body cannot make them, so we need to obtain them from our diet.

Fish and krill are the primary natural sources of omega-3. The oils extracted from these two sources are made into supplements.

However, there is also a plant-based and vegan source of omega-3, algae oil, which comes from certain types of microalgae. While there are many thousands of different species of algae, the ones you are likely most familiar with are kelp and seaweed.

Fish get their omega-3 from eating algae. Therefore, algae oil is a great source of omega-3 for vegans or for people who don't like seafood or who cannot eat it due to intolerance or allergies.

The extracted oil is often added to enrich animal feed, vitamins and supplements with omega-3 fatty acids.

What is krill oil?

Krill oil comes from krill, a small crustacean in the ocean that most sea creatures, such as whales, seals, and penguins, feed on. The word krill means "small fish."

As one study notes, in addition to EPA and DHA, krill oil is abundant in phospholipids, flavonoids, astaxanthin, vitamins, trace elements, and other substances.

What is the difference between fish oil, krill oil, and algal oil?

Fish oils are sourced from fish tissues such as mackerel, salmon, and anchovies.

According to one review paper, studies on krill oil only started in 2003, relatively later than for fish oil.

While both fish and krill oils contain EPA and DHA, according to the University of Wisconsin, the concentration of these fatty acids in krill oil products is usually less than in fish oil. Experts believe that the omega-3 fatty acids in krill oil may have a higher bioavailability, meaning they may have a higher absorption rate in the body than in fish oil.

According to Cleveland Clinic, this may be due to DHA and EPA in krill oil being stored in phospholipids, which may make them easier to absorb. On the other hand, DHA and EPA in fish oil are stored as triglycerides.

The advantage of krill oil supplementation, as a 2023 review paper reports, is that it also contains choline, an essential component for the synthesis of neurotransmitters that help pass messages between nerves and muscles.

Krill oils also contain astaxanthin, while fish oil does not. Astaxanthin is an antioxidant that also has anti-inflammatory properties. Antioxidants can help fight free radicals that can damage cells.

Algal oil is derived from microalgae and is the primary source of omega-3s for fish and other marine life. Unlike fish and krill oil, algal oil is entirely plant-based and suitable for vegans.

Most algal oil supplements are rich in DHA, although some newer formulations, such as Blackmores Plant-Based Omega Mini, also contain EPA.

The EPA and DHA omega-3s found in microalgal oil provide the same nutritional building blocks, EPA and DHA, as supplied from fish oil, and show similar health benefits to fish oil omega-3s.

Microalgae provide an alternative source of omega-3s for vegans and vegetarians, and because of their small size, they are easy to grow and represent a sustainable source of these essential fatty acids.

What are some health benefits of krill oil?

Heart health

According to the Association of UK Dietitians, countries such as Japan and Greenland, where people eat a diet rich in omega-3s, have been shown to have a lower risk of heart disease than other countries.

High levels of triglycerides in the blood can lead to heart problems.

As Cleveland Clinic reports, research shows that krill oil may effectively reduce total cholesterol and triglycerides. A 2023 review paper found that krill oil supplementation significantly lowered total cholesterol, low-density lipoprotein cholesterol (LDL), unhealthy cholesterol, and triglycerides.

Reducing inflammation

While fish oils aid in reducing inflammation, krill oils also contain the antioxidant astaxanthin, which, according to some studies, may reduce free radicals and inflammation.

Skin health

A 2020 review found many well-studied benefits of omega-3s in dermatology. The review noted omega-3s’ high safety profile, low cost, and ease of supplementation and that they are reasonable supplements that may benefit patients wishing to address skin inflammation with diet.

As a 2024 review paper reports, there has been a recent rise in recognition of the potential benefits of krill oil for skin care due to its antioxidant and anti-inflammatory effects. Krill oil contains polyunsaturated fatty acids (PUFAs), astaxanthin (ASX), and phospholipids (PL), which are known for their antioxidant and structural properties. These compounds may help support skin health by assisting with cell membrane integrity and protecting against oxidative stress.

Emerging research is exploring how these nutrients could play a role in maintaining skin hydration and structure. According to a 2024 review paper in Frontiers of Nutrition, krill contains a high amount of phospholipids, and its content can be as high as 80.69%. Phospholipids are an important component of cell membranes.

Brain & cognitive health

Omega-3 fatty acids may benefit cognition. A 2022 study published in the Neurology Journal suggests that eating them may preserve brain health and enhance cognition in middle age.

A 2024 research paper found that krill and fish oil interventions improved patients' stress symptoms. Other studies have found that dietary omega-3 fatty acids may reduce the risk of cognitive impairment.

Krill oil contains choline, while fish oil does not. According to the National Institutes of Health, choline is an essential nutrient involved in brain and nerve function. Choline is also required to form the membranes surrounding the body's cells. Most of the choline in the body comes from the food we eat.

Joints

Arthritis Australia reports that certain types of omega-3 fats can reduce inflammation and may help to relieve joint pain and stiffness.

In one 2022 study, published in The American Journal of Clinical Nutrition, krill oil was found to result in modest improvements in knee pain, stiffness, and physical function in adults with mild to moderate knee pain.

What are some health benefits of algal oil?

Heart health

DHA contributes to normal heart function and helps maintain healthy triglyceride levels.

Results from some clinical trials have shown that omega-3s derived from algal-DHA lowered triglycerides and increased both HDL (“good”) cholesterol and LDL (“bad”) cholesterol. Importantly, the rise in LDL was linked to a shift toward larger LDL particles, which are less likely to contribute to atherosclerosis — the buildup of fatty plaques in the arteries that increases the risk of heart disease and stroke.

Some participants also saw a decrease in their blood pressure, with less complaints of fishy taste reported.

Brain and cognitive health

DHA is a major structural fat in the brain and is essential for normal cognitive function. In adults, adequate DHA intake has been associated with many positive effects, including supporting cognition.

Eye health

High levels of DHA are present in the retina. Studies in both premature and full-term infants suggest that omega-3 fatty acids in the diet are important for healthy eye and vision development. Research in animals also indicates that consuming DHA may help protect the retina and support normal eye function.

Should you take krill oil, fish oil, or algal oil?

Krill, fish and algal oil offer many benefits and are ideal for those wanting to maintain heart and brain health.

Krill oil might be a good alternative to fish oil, as research suggests it could potentially be better absorbed than fish oil. It also has antioxidant properties because it contains astaxanthin. Another benefit it has that fish oil doesn't is choline, a nutrient that helps to regulate various cognitive functions. However, krill oil is generally more expensive than fish oil.

Algal oil is a great alternative for people who prefer a plant-based option or cannot tolerate fish or shellfish. It provides a direct source of DHA and is suitable for vegans and vegetarians.

While algal oil may contain less EPA than fish or krill oil, it offers a sustainable solution for meeting omega-3 needs.

How to incorporate omega-3 fatty acids into your diet

If you want to include omega-3 fatty acids in your diet, many foods contain these, with fish being the main source. Most experts advise sourcing omega-3 fatty acids from food where possible, so you can benefit from the other nutrients in the food.

The Heart Foundation recommends aiming for 2–3 servings of fish per week and various nuts, seeds, and oils to provide 1 gram of plant-sourced omega-3 alpha-linolenic acid (ALA) daily.

ALA is a plant-based source of omega-3, which the body can convert to DHA and EPA. Good sources of these are flaxseeds, chia seeds, walnuts, pumpkin seeds, and canola oil.

Because DHA is important for foetal growth and development, pregnant mothers are encouraged to eat seafood during pregnancy. However, it is important to choose fish that are lower in mercury and limit intake.

If you find it hard to include fish in your diet, for example, you might want to consider a krill oil supplement.

Anyone, including pregnant women considering taking fish oil or krill oil supplements, should seek the advice of their GP first.

It is best to consult your healthcare provider about how much omega-3 you need. Your medical history can mean you need different amounts in order to benefit.