Omega 3 Supplements – Fish, Krill or Algae?

For a non vegetarian food supplement source of EPA and DHA the ongoing debate this past few years has been ‘which is better – fish or krill oils?’. Fish oils traditionally dominated the EPA and DHA supplement market but the arrival of krill oil a few years ago has shifted this popularity substantially. This is a weighty nutritional debate for both professional health practitioners (and their patients) and the public in general looking for a suitable Omega 3 supplement.

‘Essential’ Omega 3 – EPA & DHA

The Omega 3 Essential Fatty Acids have to be derived from food, and are crucial for a range of functions including brain, heart and eye health. Crucial at all stages of life but particularly in preconception, pregnancy and childhood years.

Besides fish and shellfish , the omega 3 metabolites EPA and DHA are hard to find in a typical diet, and many people have reduced fish consumption due to pollution concerns. Hence the popularity of fish and krill oil supplements. For vegetarians and vegans their options have of course been even more limited in terms of diet and supplementation (typically flaxseed oil). Many people who eat fish or take fish or krill supplements are also troubled by sustainability issues, and we will cover this point later.

Omega 3 from Algae?

Now a third entrant to the Omega 3 supplement marketplace offers a serious alternative for the entire interested ‘audience’ including vegetarians and vegans. Omega 3 from algae grown in a controlled environment temptingly overcomes sustainability, pollution and vegan issues, it is rich in EPA and DHA plus it has other natural and unique nutritional attributes, primarily in terms of ‘Phlorotannins’. These are a type of tannins found in brown algae that are rich in antioxidants and attracting a lot of recent and positive research in to their potential health benefits, and more on this later.

Form and Nutritive Values

‘Form’ is a term we have used many times when debating the efficacy of food supplements (for example our ‘Food State’ form vitamins and minerals). And form is the key here in this Omega 3 debate between the three options – fish, krill and algae. What unique nutritional attributes do each of these three forms offer to make them attractive? Is each form indeed better suited to certain groups of people? Then we have the factors of nutritive dosage values, efficacy and bioavailability (uptake in the body), sustainability, food source, and pollution questions.

It’s important at this stage to comment that for the Omega 3 EFA’s aspect – when comparing supplements (whatever the form) – check the nutritive value not the dose! The krill or fish oils will come in a liquid or capsule form yet only a proportion of each mg will contain EPA and DHA – and this will differ between products. So don’t focus, for example, on the amount of liquid in a krill capsule but the amount of beneficial EPA and DHA. But even then this is only part of the comparative debate – how bioavailable are these nutrients for our body dependant on the form they are delivered in (i.e. fish, krill or algae)?

We have a number of existing blog articles on fish oil, krill oil and Omega 3 and the latest science; and links to these items are provided further below. More particularly we have a specific in-depth article comparing fish and krill supplements that may be of interest to some of you. But if fish, algae and krill oils supplements are all of interest to you (or more than one) how can you do next to evaluate the choices? Let us explore.

Krill Oil

The public awareness of krill oil supplements has been substantially elevated over (say) the past five years. Back then we were one of a handful of companies recognising the attributes of the substance and selling an appropriate product. Now all the mainstream supplement companies supply a krill oil. One company launched their product to tremendous fanfare some year or so ago, with lots of TV adverts and displays in a high street chemist, and this further raised the profile of the nutrient.

Not only does krill oil provide good natural levels of Omega 3 EFA’s EPA and DHA it also has a number of additional natural nutritional attributes and these can be summarised as:

  •  Choline – krill phospholipids contain choline, an essential nutrient, and neurotransmitter precursor important to brain and muscle tissue;
  • Astaxanthin – a carotenoid molecule found in krill oil with powerful antioxidant activity;
  • Phospholipids – unlike fish oils the Omega 3 fatty acids in krill are more efficiently absorbed by our body as they are carried to our body cells in a ‘phospholipid’ form. Phospholipids are an important class of ‘lipids’ in our body that support construction of cell membranes.

Krill Omega 3 fatty acids are bound to phospholipids where it is considered that they are more efficiently absorbed via the small intestines with the phospholipid complex readily absorbed into the cell membranes. Other sources of Omega-3 fatty acids such as fish oil are bound to triglycerides, which are insoluble and require bile salts for their emulsification and absorption via the lymphatic system.

In addition krill oil contains the previously mentioned antioxidant tannins phlorotannins. We will be covering these compounds later in the section on algae’s which are rich in phlorotannins. However it is relevant to note that krill eat brown algae and hence the presence of these beneficial tannins.

A number of people raise concerns for sustainability in respect of krill supplements. Reputable suppliers of krill oil supplements will harvest within the strict guidelines of CCAMLR (the Conservation of Antarctic Marine Living Resources) which was established to conserve marine life in the Southern Ocean. If you are in doubt regarding this point and a supplement then contact the supplier. For those who are interested, for example, we have a number of pdf’s from the manufacturer of our krill oil product that detail their sustainability credentials and procedures (simply email me for these, details below).

Fish Oils

As we noted at the start of this article fish oil products have historically dominated the Omega 3 marketplace in food supplements for some considerable time. As fish consumption has declined over time, and the importance of Omega 3 for our health has been commensurately reinforced, fish oil supplements sales have grown strongly.

With their rich natural content in the EFA’s EPA and DHA this has been the nutritional marketing focus for relevant products. And I think most of us are familiar with ‘good old’ cod liver oil. However a primary point to note is that fish oils either come from the fish body, or liver, or both. If the oil has come from fish livers then there are additional nutrients to note and be aware of:

  • Fish liver oils are high in vitamins A and D as these are stored in the livers of oily fish; However pollution in fish is concentrated in the liver so you need to ensure the product is pollutant free;
  • Whole body fish oils only contain a small part of the livers in total and hence a much lower level of vitamins A and D. Cod liver oil for example is high in vitamins A and D;
  • This is an important point as some population groups should avoid excessive vitamin A, primarily pregnant women and also older men;
  • Pregnant women are advised by the NHS not to have too much vitamin A (Retinol) in either food or supplement forms.

When it comes to eating fish obviously there is a regularly updated list of sustainable fish available. With a fish oil it’s more a case of accepting that you have chosen an Omega 3 product that comes from a variety of fish that have been harvested. However fish oils should ideally come from whole oily fish such as sardine and anchovy. These are ‘low food chain feeding’ fish largely eating algae, as opposed to other species which are considered less ‘clean’ as they eat other fish and shellfish. Mackerel in particular are an oily fish, but as a scavenger they can be heavily polluted.

Many people have been dissuaded from fish oil supplements, which predominantly come in a capsule container or liquid, due to a fishy odour or aftertaste. This is generally much less of an issue with krill oil capsules.

Vegan Omega 3 from Algae

Algal Omega 3 oil has been available in supplement form for a while – but it did not contain meaningful amounts of EPA. More recently this nutritional issues has been addressed as oil derived from dried marine plant microalgae such as Schizochytrium sp. (DRM) is rich in the EFA’s EPA and DHA.

The microalgae in such a supplement is grown in a strictly controlled environment, eliminating the risk of oceanic contamination. The Cytoplan product for example is produced in an FDA-inspected facility, under current Good Manufacturing Practice (cGMP) regulations.

So we can see why such supplements should prove to be a tempting option for vegetarians and vegans seeking an EPA and DHA product. In addition the use of algae rather than fish or krill may appeal to many people concerned about sustainability issues. We have noted the unique nutritional attributes of krill earlier, and this is likely to sway many to remain loyal, or choose for the first time, krill for Omega 3 support. However algae Omega 3 has some unique nutritional attributes too and the focus here is phlorotannins.

Research for algae derived DHA & EPA is demonstrating superior effectiveness over fish oil sources. It is believed the Phlorotannins could be the main responsible component of this finding. Phlorotannins are high in polyphenols and these are potent antioxidants found in brown algae.

Polyphenols are organic chemicals naturally found in many foods, indeed they are the most abundant antioxidants available in the human diet. But again it’s a tale of ‘healthy eating’ as good food sources are fruit and vegetables. Many people are familiar with the issue of ‘free radical’ damage and polyphenols help to prevent the damage of free radicals in the body. The evidence for their role in the prevention of degenerative diseases such as cancer and cardiovascular diseases is emerging.

Polyphenols are highly protective plant flavonoids. They are powerful antioxidants with conferred ‘all tissue’ benefits bestowing antioxidant, anti viral, anti-cancer, anti-proliferative and anti-allergic activity. The polyphenolic structure comprises 3-carbon ring with various substitutions – hence it is a very stable structure with the ability to donate multiple electrons – which is the nucleus of its profound antioxidant activity.

If you are not a vegetarian or vegan but are interested in the attributes of phlorotannins in addition to EPA and DHA then don’t forget that these tannins are present in krill oil as krill eat brown algae and hence the presence of these beneficial tannins. Fish will also eat algae, in varying amounts, therefore they too will have ingested phlorotannins but these will have been converted to antioxidants in their body and in cell storage to protect the fish. It means that the lower food chain feeding fish will have more antioxidants within their flesh but not free flowing phlorotannins.
Phlorotannins, and EPA and DHA products derived from algae have been the subject of recent research, and also received a good level of media interest recently. And we provide some pertinent links further below.


Astaxanthin is a carotenoid molecule found in krill oil with powerful antioxidant activity. If you are not vegetarian or vegan one of the additional selling points for krill oil as an Omega 3 supplement is its naturally occurring levels of astaxanthin. So this may sway you in your decision between the krill oil supplement and algae Omega 3 which does not naturally contain astaxanthin.

Algae Omega 3 supplements are available with astaxanthin but this has been added separately, and one needs to be wary also of synthetic astaxanthin being used. When selecting a krill oil supplement also make sure that the astaxanthin present is in naturally-occurring levels as many companies add in synthetic Astaxanthin to elevate levels.

Fish and Krill Oils and Cholesterol

We ought to note that there has been an ongoing research debate for some years as to whether fish oils (taken above certain dosages and frequencies) may elevate ‘bad’ cholesterol levels. A quick recap, as I think many people are confused by the classic ‘are avocado’s and egg’s good or bad’ question, is that ‘HDL’ is  good cholesterol, whilst ‘VLDL’ and ‘LDL’ are bad cholesterol.

There is plentiful information readily available on the topic of fish oil, krill oil and LDL by searching online. A further ‘plus point’ for krill oil is research in support of its potentially beneficial effect in regards to cholesterol including increasing the beneficial HDL cholesterol. A good example of an online search you can conduct is by typing in ‘research + fish oil + LDL + raise’ into a search engine. Or transpose the words appropriately – for example change fish oil to krill oil, change ‘raise’ to ‘lower’ etc. So just two examples of pertinent research:

The American Journal of Clinical Nutrition – Fish oil and cardiovascular disease: lipids and arterial function. “In contrast, LDL-cholesterol concentrations have often been noted to rise and the potential of increased oxidizability of LDLs is potentially adverse with lipid modification.”

Science Direct – Krill oil supplementation lowers serum triglycerides without increasing low-density lipoprotein cholesterol in adults with borderline high or high triglyceride levels.

Flaxseed Oil, Vegetarians & Vegans

Prior to the arrival of algae EPA & DHA vegetarians and vegans often chose flaxseed oil supplements for their Omega 3 needs. Flaxseed oil supplements are rich in ALA (alpha-linolenic acid). Flax oil may not be the best source of EPA and DHA as the long chain ALA needs to be converted to EPA/ DHA in the human body, and this process is often not efficient. But it is high in Alpha linolenic acid and if gently cold pressed will also contain other beneficial nutrients – carotenoids, mainly beta carotene and vitamin E which are naturally present to protect the Omega 3 fatty acid in the plant and then oil.

There will also be a good quantity of phospholipids in a good cold pressed oil and the flax lignans have gentle phyto oestrogenic activity. It can also be ingested in quantities up to 30mls a day for those with dry skin or who need to increase level of fatty acids in the body. It can be used as a dressing on foods but should never be heated. My ideal programme for people wanting to obtain all the benefits offered by Omega 3 products and other essential fatty acids is to take either krill or vegan EPA/ DHA for the EPA and DHA and then to use flax oil or other cold pressed nut or seed oils including avocado oil as dressing for salads and other foods.

Relevant Links

Nutraingredients – Battle of the omega-3 forms: Triglycerides, ethyl esters, or phospholipids?

Nutraingredients – Omega-3 Fatty Acids and Heart Health: Algal, Krill or Fish Oil Supplements

Science DirectAntioxidant properties of phlorotannins from brown seaweed

National Center for Biotechnology Information – Marine Bioactives as Functional Food Ingredients: Potential to Reduce the Incidence of Chronic Diseases

Science Direct –Phlorotannins as bioactive agents from brown algae

Cytoplan Blog – Krill & Fish Oil Supplements

Cytoplan Blog – Omega 3 for the Family

Cytoplan Blog – EPA & DHA – A closer look at the latest research

Omega 3 Permitted Health Claims

Following are the five current permitted EFSA health claims for Omega 3 (subject to a daily intake of 250mg of EPA and DHA).The last permitted health claim is for choline and only applies to krill oil.

  •  Contributes to the maintenance of normal brain function
  • The maintenance of normal vision
  • The maintenance of normal cardiac function
  • The maintenance of normal blood pressure
  • The maintenance of normal (fasting) blood concentrations of triglycerides
  • Choline contributes to the maintenance of normal liver function


So what next for those of you considering what supplement form to take for your EPA and DHA needs? The evidence would suggest that if you are not a vegetarian or vegan then krill oil with its additional nutritional attributes should be favoured? For those concerned about the food sources or sustainability of krill or fish oils then Omega 3 from algae must present a serious option, especially when you factor in the current research on phlorotannins.

Fish oils continue to sell strongly in this sector of the marketplace and no doubt will continue to do so. Particularly as many of us associate Omega 3 with fish. It’s wonderful and exciting to have the new algae Omega 3 supplement as an alternative. Without doubt the debate and research as to the merits of each of these three forms will continue to be in the spotlight.

Hopefully we have given you enough information in this article to help your educational understanding of some of these products. As we mentioned the internet is a wonderful place to search for either technical (e.g. research) information, or from a consumer point of view.

In addition you can discuss the options with a qualified health professional or contact the manufacturers or suppliers of such supplements.


Krill Oil and fish oil is not suitable for those who are allergic to shellfish, fish or fish-related products. Those on warfarin, heparin or other anticoagulant medication should consult their doctor before taking krill oil, fish oil or algae Omega 3.

If you have any questions regarding this article, any of the health topics raised, or any other health matters please do contact me (Amanda) by phone or email at any time.

Amanda Williams, Cytoplan Ltd, 01684 310099


Last updated on 5th March 2020 by cytoffice


20 thoughts on “Omega 3 Supplements – Fish, Krill or Algae?

    1. Dear Tony,

      Many thanks for your interesting question. I would suggest that the vegan algae oil is the best option in this instance as fish (like sardines) and shell fish are high in purines. Do contact me directly if you would like more information; Best wishes, Amanda

  1. Hi,
    Thanks for the article, it’s really interesting. Would algae supplements be suitable for pregnant / lactating women? I’m wondering if they are also high in vitamin A?
    Many thanks

    1. Dear Emma,

      There is no vitamin A in algae products and therefore they are certainly suitable for pregnant/lactating women. Would you like me to send you a pot of our Vegan Omega 3 to try? Please email as such – and also if you would like any other feedback on nutrition for pregnancy.

      Best wishes, Amanda x

  2. Hi! Thanks for the interesting article. My husband has epilepsy and we are always looking for good nutrients for both of us. Omega3 is said to be essential for good brain function. We are mostly vegan, but sometimes I wonder if we need to include any fish/eggs in our diet. The algae option sounds good… For now, we are having flax seed oil and ground flax seed with our breakfast every day.

    1. Hi Ana,
      Many thanks for your comment on our blog. If you would like some diet and supplement recommendations to support your health goals or any symptoms that you are experiencing, we would recommend that you fill out a health questionnaire and return it to us. Clare, our Nutritional Therapist will then send you some written diet and supplementary recommendations relating to your individual circumstances. This is a free service. Please do get in touch if you would like us to send you one via post or e-mail.

      Best wishes,

  3. I am 6 weeks pregnant and I need omega 3 fish oil molecularly distilled to remove pesticides, PCBs and heavy metals, including mercury. Do you have this supplement please. I am taking Pregna-plan also folate and B12 from cytoplan everyday but was told to also take fish oil.

    1. Hello Olga,

      We supply Fish Oil from whole oily fish such as sardine and anchovy. These Fish Oil supplements are clean, stable and have no trace of any ocean pollutants or heavy metals. I would be more than happy to arrange to send you a pot of fish oil in the post – if you can e-mail me your address ( then I will send this out as soon as possible.

      Many thanks,

      1. Hi I’m pregnant and I would like to start take a dha algae oils and I’m not still sure is it real natural for me and baby

        1. Dear Marlena,

          Thank you for your question about our algal omega-3. Our omega-3 vegan is a natural product. It is from microalgae which are grown in a controlled environment, eliminating the risk of oceanic contamination. The algal species is called Schizochytrium sp. microalgae. The supplement provides both EPA and DHA omega-3 fatty acids.

          All the best,

  4. Which DHA is best for pregnant women and what daily dosage is optimal? I am at the beginning of pregnancy and looking foor a good sources of DHA.

  5. We’ve recently turned vegan as a family and have been taking flax and chia seeds. I’m realising this is not enough, but am concerned about carageenans in seaweed. Could you thow some light on this subject. Thank you.

    1. Hello,

      Many thanks for your comment on our blog. Carrageenan is naturally found in seaweeds and is also used as a thickener in some products. There is concern that in some sensitive people it may contribute to gut issues. There is a minute amount in the Omega-3 Vegan capsules. Larger quantities are found in some non-dairy milks such as coconut and almond milks. I hope this is helpful to you. If you have any further questions please contact me (

      All the best,

  6. I have neuritis. Although astaxanthin brings blood pressure down, which type of oils would benefit me? With thanks.

    1. Hello Mrs Johnston,

      With regard to an oil, as you are already taking astaxanthin, I would suggest our High Potency Fish Oil (2 capsules per day). An anti-inflammatory diet is also important – plenty of vegetables (6+ portions per day not including potatoes), 2 portions of fruit, healthy fats (avocado, olive oil, oily fish, coconut oil, nuts/seeds) and low in sugary foods.

      Have you had B12 levels tested? If not I suggest you discuss this with your GP. Serum B12 is not an accurate indicator of B12 so you could also discuss testing for homocysteine which gives an indirect measure of B12 levels. Supplements containing B12 will affect the results however.

      Regardless of the test results, I suggest an all round multivitamin and mineral with good levels of B vitamins which are important for nerve health – CoQ10 Multi would be my recommendation. Start with 1 per day for 7 days, then increase to 2 per day. This does contain 200 mcg of B12 as methylcobalamin and adenosylcobalamin. I suggest that you also include some additional B12 hydroxycobalamin. We would be more than happy to send you a couple of pots to get you started, so if this is of interest please just drop me an e-mail (

      If possible, understanding the cause(s) of the neuritis is important as there may be other foods / supplements or lifestyle measures that you can take or improve. You may be interested in our free health questionnaire service. If you complete and return a health questionnaire we will send you some diet and supplement recommendations. This is a free service.

      All the best,

      1. Hi.
        I am breastfeeding and about to buy pregna plan from your brand. I am looking at some omega 3 to complement along side with pregna plan, but I am undecided about which one is better. The krill oil vs algae, which would bring I get more benefits from?
        I was inclined to get the krill because it looks more absorbed by our body although it looks less quantity in the nutritional information.
        What’s your opinion?
        Thank you

        1. Hello – yes the Pregna-plan would be beneficial during this period to support nutrient status for yourself as well as the infant. Our Omega 3 Vegan would be the most appropriate form of omega 3s for during this time. This is due to it being a very well absorbed form and being rich in DHA that is so important for foetal brain development.

  7. Excellent article. It gives very clear information on all the sources of marine EFAs. I know now which supplement is best for me.
    Thank you.

  8. I really appreciate the way you have explained the benefits between OMEGA, Krill and algae. I think Krill is my best option. Thank you.

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