Published on April 26, 2021

Krill Oil vs Fish Oil: Which Should You Take?

Krill Oil vs Fish Oil: Which Should You Take?

Omega 3 fats are essential in our diet, and there are lots of different sources, such as oily fish, nuts, seeds, and also supplements. There are pros and cons of both food sources and also supplements. So, in this article, I will guide you through the advantages and disadvantages of Krill oil vs fish oil supplements. I’ll also cover who needs to take these supplements, and if krill oil is better than fish oil, and cod liver oil.

What Are Omega Fatty Acids?

There are two types of fats or fatty acids that are essential and can’t be produced in our bodies. These are omega 3 and omega 6. Omega 3 can be broken down into three main forms: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

Where Are Omega Fatty Acids Found?

ALA is found in plant oils, such as flaxseed, soybean, and canola oils. DHA and EPA are found in oily fish, fish oils, and krill oils. DHA and EPA are actually synthesized by microalgae—not by the fish—but accumulate in the tissue when they are eaten by fish and shellfish further up the food chain.

Why Are Omega Fatty Acids So Important?

Omega-3 and -6 fatty acids have an important structural role needed for cell membranes. They are also energy sources and are used to form signaling molecules called eicosanoids, comprised of prostaglandins, thromboxanes, and leukotrienes.

There are many different prostaglandins with wide-ranging roles, such as the sensation of pain, inflammation, regulation of pregnancy and birth, control of blood pressure, secretion of stomach acid, contraction, and relaxation of smooth muscle.

Thromboxanes regulate blood clotting by causing constriction of blood vessels and the aggregation of platelets (so they stick together), which are early steps in blood clotting.

Leukotrienes are involved in immune function by attracting immune cells such as neutrophils to sites of inflammation. They also constrict bronchioles in the lungs and make capillary walls permeable.


This is thought to be because the metabolic products of omega-3 fatty acids are less inflammatory than those produced from omega 6 fatty acids. Western diets are associated with an imbalance of omega-3, -6 such that instead of levels of omega 3 being higher than 6, the reverse is more commonly seen. This is associated with an increased risk of chronic inflammation.[1]

A large systemic review that combined 86 trials involving over 162,000 people looked at the effect of higher omega-3 intake versus lower omega-3 intake for at least a year. This was provided mostly by omega-3 supplements while a few trials gave oily fish. Omega-3 fatty acids have been shown to reduce blood pressure and can be incorporated into your diet by eating oily fish or seeds, such as chia seeds, flax seeds, and nuts.[2]

There are three types of omega-3: those found in oily fish called EPA and DHA and the plant-based ALA.

What Is Krill Oil?

Krill oil is extracted from the bodies of Antarctic krill, a tiny shrimp-like shellfish. Krill oil, fish oil, and cod liver oil are similar in that they all contain DHA and EPA.

Fish oil is extracted from the body of the fish and contains some vitamin A and vitamin D as well. Cod liver oil is extracted from the liver of the fish and contains higher levels of vitamin A and D.

High doses of vitamin A can be toxic as it is a fat-soluble vitamin that is stored by your body. This is why omega 3 supplements that contain vitamin A are to be avoided in pregnancy because high levels of this vitamin may damage the fetus.

Krill Oil Vs Fish Oil

Evidence surrounding krill oil is limited compared with fish oils and cod liver oils. A large portion of the EPA and DHA in krill comes in phospholipid form (whereas fish oil fatty acids are contained in triacylglycerols), which some claim has a higher rate of absorption in the body than fish oil.


Previously, it was thought that Krill oil was more bioavailable than fish oil, but there were problems with this research with regards to dosing.[3] More recently, a randomized controlled trial in 66 people was performed to answer this question and compared the bioavailability of krill oil compared with fish oil. It found that there was no difference between blood measurements of DHA and EPA. Therefore, the evidence does not support krill oil being “better” or needing lower doses than fish oil.[4]

Krill Oil Vs Fish Oil in Terms of Cholesterol

A study in animals looked at gene expression after supplementation with either krill oil or fish oil. They found that fish oil upregulated (increased gene expression) the cholesterol synthesis pathway more than krill oil. Krill oil was found to upregulate (increase gene expression) more metabolic pathways than fish oil. This suggests that there might be different biological effects between krill and fish oil but more research is needed.[5]

In group (meta) analysis of seven trials totaling 662 participants, Krill oil supplementation was found to reduce low-density lipoprotein cholesterol and triglycerides but not total cholesterol.[6] Whether this translates to decreased risk of cardiovascular disease needs further research.

However, when directly compared, krill oil was not superior to fish oil supplementation and had very similar effects on cholesterol.[7]

Krill Oil Vs Cod Liver Oil

Cod liver oil contains higher levels of vitamin D and vitamin A, which may be toxic in excess. If you want to take a high dose of omega-3, this means you will also end up having higher doses of vitamin A and D. Both of these are fat-soluble vitamins that are stored by the body and can become toxic. Vitamin A supplementation should be avoided during pregnancy due to risks for the baby.

There is a risk that since the liver is used to filter out toxins, there is the possibility that cod liver oil contains more environmental contaminants than fish oil or krill oil.

Are There Risks With Krill Oil?

Less research has been performed on krill oil and although no side effects have been reported, the safe maximum dose of natural astaxanthin has not been determined.


Krill make up a vital part of the Antarctic food chain and a huge number of species higher up the food chain depend on them. Fishing krill has the potential to catastrophically destabilize this important food chain. Therefore, fish oils are more sustainable than krill oil.

Why Is Krill Oil Red?

The deep red color of krill oil is due to a compound called astaxanthin found in krill. Astaxanthin is also found in other more sustainable sources such as red trout, crab, lobster, and wild salmon. Astaxanthin is a carotenoid antioxidant compound that mops up harmful free radicals.

When to Take Omega-3 Supplement

A large review of 86 trials combined—totaling over 162,000 people—looked to see what the effect of increased omega-3 had on cardiovascular risk. Increasing ALA made no significant difference to blood clots of the coronary arteries supplying the heart (coronary events) but slightly reduced cardiovascular events (diseases related to blood vessels such as clots and rhythm problems) while EPA and DHA reduced serum triglycerides and also reduced the risk of coronary heart disease, such as heart attacks.[8]

They found that EPA and DHA decreased triglycerides (a type of fat) by about 15% and reduced the risk of coronary artery death and coronary events, which are illnesses of arteries supplying the heart. However, they did not affect cardiovascular events (e.g., strokes, heart irregularities).[9]

While increasing ALA made no significant difference to coronary events, it slightly reduced cardiovascular events. This means that the three combined (ALA, EPA, and DHA combined) may reduce the risk of coronary, cardiovascular disease, and lower triglyceride levels, but the effects are small.

One of the ways of decreasing your risk of cardiovascular disease is by lowering your cholesterol—reducing saturated fats in your diet and eating ALA omega-3 (e.g., from walnuts). A grouped meta-analysis has not found any link between omega-3 and dementia, but more information is needed to see if omega-3 can prevent cognitive decline.[10]

Overall, if you aren’t pregnant or intending to get pregnant, then omega 3 supplements are probably unlikely to do you harm and might benefit your long-term cardiovascular risk. It isn’t possible to tell the difference in general between eating enough omega-3 in your diet versus supplementing, but whole foods have other benefits as well.


Omega-3 supplements often have high levels of vitamin A, which can be harmful in pregnancy. Therefore, you should avoid supplementing or choose a pregnancy-safe version.

If you are vegan, you may consider taking an omega-3 supplement made from algae or seaweed, but these are unregulated and can contain significant quantities of iodine, which can be harmful. Therefore, it is better, where possible, to optimize your diet. There are concerns that part of the benefit of omega-3 is from a whole food effect that isn’t seen with taking a supplement instead.

Tips on How to Get Enough Omega-3 in Your Diet

  • Aim to have oily fish twice a week if you aren’t pregnant or once a week if you are, as the benefit of omega-3 has to be offset by the risk of contamination with heavy metals.
  • Algae and seaweed are the only plant-based sources of EPA and DHA, but ALA can be converted in your body into EPA and DHA.
  • Vegan sources of omega-3 are chia seeds, linseed, hemp seeds, walnuts, and vegetable oils, such as rapeseed. To meet the current guidance for omega-3, you would need to eat about a tablespoon of chia or ground linseeds, or two tablespoons of hemp seeds, or six walnut halves a day.
  • Algae oil is an alternative to fish oil, which makes it an attractive option for vegetarians. But while algae oils do contain large amounts of DHA, most don’t contain any EPA fatty acids at all.

In Summary

Krill oil supplements appear to be safe and as effective as fish oil. They also have the bonus of containing the antioxidant astaxanthin.

However, harvesting krill is not sustainable, and there are risks regarding destabilizing the Antarctic food chain. Instead, aim to include foods rich in omega-3 in your diet to benefit from the “whole food effect,” and eat foods that are naturally rich in carotenoids, such as vegetables, crab, and lobster. Avoid taking high doses of cod liver oil, and avoid it completely during pregnancy due to the risk of vitamin A.

Featured photo credit: Anshu A via


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Dr. Harriet Holme

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Published on May 6, 2021

15 Best Foods Rich in Omega-3

15 Best Foods Rich in Omega-3

Foods rich in omega-3 are very important for every living person. Omega-3 foods provide nutrition for good health, energy, and focus to help us become more productive. These foods go well with daily meals or can also be used as the main ingredient. Fish, seafood, nuts, and plant oil are a few foods people need to eat to get omega-3.

Here are the 15 best foods that are rich in omega-3 that you should add to your diet.

1. Shrimp

In many restaurants, shrimp plays a major role in delicacies. It’s delicious, very nutritious, and easy to cook. Shrimps contain antioxidants to help boost immunity and fight infections. They also contain omega-3, which is very helpful in fighting heart conditions.

However, you also have to be careful. Shrimp also contains plenty of cholesterols that affect blood flow.[1] So, make sure you eat them in moderation.

2. Mackerel

Fans of white fish will love eating mackerel because of the tremendous amount of omega-3 it contains. For every four ounces of the fish, there is about 2,700 mg of omega-3. Mackerels are very affordable and have been a healthy food source for centuries.

There are several recipes online you can copy to create awesome meals for you and the family. People with mental disorders will also benefit a lot from omega-3 as eating mackerels help reduce the symptoms of schizophrenia and bipolar disorder.[2]

3. Chia Seeds

Vegans love chia seeds because they contain omega-3, making them good for heart health. Also, they’re quite easy to make. Unlike flaxseed, you don’t need to grind them. You can eat them raw, make them into pudding, add them to a smoothie, or include them in your baking. Some people also like to sprinkle them on vegetables and yogurt.


Eating chia seeds may also aid in weight loss, especially when combined with exercise.[3] The omega-3 content can also help improve eye health. People with eye problems have a low amount of omega-3 in their bodies.[4] That’s why eating these seeds is good for reversing problems with eyesight.

4. Kidney Beans

You can also get omega-3 from eating kidney beans. Even though it’s in low concentration, it still provides you with some of that useful nutrient. Along with omega-3, kidney beans supply protein, fiber, antioxidants, and plant compounds. It also promotes colon health, aid weight loss, and moderates sugar levels.[5] You can add kidney beans to hot or cold salads, side dishes, pasta, and soup.

5. Salmon

Oily fish is one of the foods richest in omega-3, so they are high in demand. Salmon is very important and is regarded as one of the most nutritious foods on the planet. They contain omega 3, vitamin B-6, cobalamin, magnesium, protein, and saturated fats.[6]

People experience inefficiency in personal life because of a low amount of omega-3. Eating salmon can help boost energy and increase productivity because of its abundance of omega-3. Wild salmon contains 3,428 mg of omega-3 in 198 grams, the second-highest in the world.[7] There are several recipes online for adding salmons to food. Children will benefit a lot from eating salmons because it also helps develop brain cells.[8]

6. Flaxseed Oil

People who are looking to increase their heart health turn to flaxseed. It’s one of the foods rich in omega-3 and is good for cooking. Consuming flaxseed oil help reduce cancer cell growth and treats constipation and diarrhea.[9]

The omega-3 content also helps improve skin health and reduce inflammation. Eating flaxseed oil raw is the best thing to do. You can also add it to salad dressing or sauces or use it in low-heat cooking.

7. Brussels Sprout

For those who love vegetables, brussels sprout is one of the best foods rich in omega-3. Cooked Brussels sprout contains 135 mg of omega-3 per 78 grams. Apart from omega-3, the vegetable also offers fiber, vitamin K, and antioxidants.[10]


Adding the vegetable to a meal is very easy. It’s simple to prepare and cook, and there are several recipes online you can copy. Brussel sprouts are also very delicious, and they provide many health benefits.

8. Walnut

Eating walnut is one of the healthiest things anyone can do. All you need to do is soak them in water overnight and munch them in the morning. People also like adding them to cereals for the flavor and taste.

There are benefits of eating walnuts, including decreased inflammation and promoting gut health. But their high omega-3 content remains the best reason for eating them. Walnuts also lower blood pressure and help you improve in physical activities.[11] You can find walnuts in stores or buy them online fresh.

9. Avocadoes

It’s no surprise that avocado is on the list of best foods rich in omega-3. Even though it contains low amounts, it’s still one of the best to consume. Avocado has a superfood status because it contains a large amount of healthy fats and oils. It’s delicious, easy to cook, and can be eaten raw or added to other meals. They contain more potassium than bananas, are good for the heart, and help lower cholesterol.[12]

Most people who eat avocado regularly tend to be healthier than those who don’t. There are several recipes for making delicious avocado for consumption. Guacamole is one of the most popular, which has become a part of international cuisine.

10. Red Lentils

Protein, iron, and potassium are the main reasons people eat red lentils. Also, the edible legume is one of the best foods that are rich in omega-3. Eating red lentils is also good for the skin, helping you have that fabulous glow. It also supplies magnesium, which aids the flow of blood and oxygen around the body.[13]

You can also get folate from red lentils. These nutrients all work to improve blood vessels and promote a good heart. You can cook it, eat it alone, or add it to salads and vegetables.


11. Mustard Seed

Eating mustard seed or mustard oil is good for health in many ways. It’s one of the foods in the world that provides healthy oil goods for consumption. Mustard seed contains not just omega-3 but also omega-6 and other saturated fat content. It also promotes energy and vitality.[14] Are you feeling tired and unable to do what you want? You can improve your productivity by chewing on some mustard seeds.

It also supports heart health, reduces inflammation, and treats colds. There are several ways to eat it. You can add to salads, sprinkled inside warm meals, or added to milk. The best way to consume mustard seed is by making it into a mustard paste. Then, it can go into salad dressing and other things.

12. Spinach

Eating leafy green plants is good for the health because of their nutrients. They also give energy and reduce oxidative stress. Spinach contains plant compounds like lutein, which is good for eye health. It also contains nitrates, which help to protect the heart and boost energy. You will get vitamin A, K1, C, and folic acid from it as well.[15]

Spinach is one of the best sources of omega-3 for people who love leafy vegetables. 100 grams of spinach has 370 milligrams of omega-3. Eating spinach energizes the body and helps promote an active and healthy lifestyle.[16] The garlic sautéed spinach is a delicacy that is well-known and appreciated around the world.

13. Navy Beans

People eat navy beans because of fiber, thiamine, magnesium, manganese, and folate. It also contains some amount of omega-3. If you love beans, then navy beans are an excellent way to get omega-3 into your system. The omega-3 in navy beans helps regulate sugar blood levels to prevent or manage diabetes.[17]

It also improves digestion, promotes blood circulation, and repairs damaged tissue. Navy beans soup is a delicacy that many people enjoy. You can eat the beans with bread for breakfast. The folate in navy beans provides energy, which keeps you active all day.

14. Caviar

People pay thousands of dollars to have a taste of caviar. The food comes from the roe of wild sturgeon in the Caspian Sea and the Black Sea. It’s one of the most expensive foods rich in omega-3. So, when you’re paying that high amount, you know you’re getting something worthy.[18]


There are several types of caviar distinguished by color and other factors. Beluga caviar is about the most expensive, which costs about $8,000 per kg. Caviar also has vitamin B12, A, E, B6, selenium, and magnesium.[19]

15. Sardines

For every three ounces of sardines, you get two grams of omega-3. Sardines have been a favorite food for centuries due to their healthy oil content that promotes heart health and also because they are very delicious.

They also contain vitamin D and calcium, which improves heart health. They are mostly served in cans, but some consume them grilled or smoked. There are several ways to eat sardines, including adding them to salads. Some people eat them straight out of the can, while others add pepper, salt, and garlic before consuming them.[20]

You can also add sardines to pasta to enrich the flavor and taste. Sardines are tasty and will help protect your heart and reduce inflammation.


Omega-3 is a nutrient that promotes good heart health, boosts immunity, and fights inflammation. You can live a healthy life by consuming foods that are rich in omega-3, along with a well-balanced diet and physical activity. This list of the 15 best omega-3 foods will help you add a variety to your meal plan while still staying healthy.

More Healthy Omega-3 Foods You Should Try

Featured photo credit: leonie wise via


[1] College of Tropical Agriculture and Human Resources: Nutrition Considerations in Aquaculture: The Importance of Omega-3 Fatty Acids in Fish Development and Human Health
[2] Healthline: How Omega-3 Fish Oil Affects Your Brain and Mental Health
[3] Healthline: Chia Seeds and Weight Loss: What You Need to Know
[4] Harvard School of Public Health: Chia Seeds
[5] Healthline: Kidney Beans 101: Nutrition Facts and Health Benefits
[6] WebMD: The Health Benefits of Salmon
[7] National Institutes of Health: 7 Things To Know About Omega-3 Fatty Acids
[8] Grow by WebMD: Top 10 Brain Foods for Children
[9] Healthline: 6 Benefits of Flaxseed Oil — Plus How to Use It
[10] Healthline: 10 Ways Brussels Sprouts Benefit Your Health
[11] Forbes: Why The Omega-3s In Walnuts Are Not The Same As The Ones In Fish And Algae
[12] Cleveland Clinic: Why Avocados Are a Healthy — and Delicious — Addition to Your Diet
[13] Medical News Today: What are the benefits of lentils?
[14] VeryWellFit: Mustard Oil Nutrition Facts
[15] Healthline: Spinach 101: Nutrition Facts and Health Benefits
[16] SciElo: Omega-3 Fatty Acids and Antioxidants in Edible Wild Plants
[17] Healthline: The 9 Healthiest Beans and Legumes You Can Eat
[18] Effects of Scandinavian caviar paste enriched with stable fish oil on plasma phospholipid fatty acids and lipid peroxidation
[19] California Caviar: HEALTH & NUTRITION: Benefits of Caviar
[20] Medical News Today: Are sardines good for you?

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