Deciding between algae oil vs fish oil can be a tough choice.

Choosing responsibly and knowledgeably can be difficult, both from an environmental and health perspective.

You might be wondering, “Can algae oil still provide me with the same benefits as fish oil like heart health, brain health and general cognitive function?” or “Is it worth taking omega-3 supplements at all?”

Clinical trials seem to suggest that algae oil can offer comparable benefits to fish oils but recent research may be suggesting we should stick to a “food first” approach.

There is a lot to think about when it comes to omega-3 supplements which we’ll touch on in the sections below.

I have packed this blog with scientific research to help you make an informed decision.

Let’s dive in!

What are Omega-3 Fatty Acids?

Omega-3 polyunsaturated fatty acids are “healthy fats” that are vital to our overall health.

The three main types of omega-3 are Alpha-linolenic acid (ALA), Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA). ALA is mainly found in plant oils such as canola or flaxseed oil but can also be found in nuts, seeds and beans.

DHA and EPA are mostly commonly consumed through fish but can also be found in algae – a group of plant-like aquatic organisms. ALA can metabolise to DHA and EPA, but this process is slow and it doesn’t quite reach the levels needed for optimal health.

For that reason, it’s crucial to consume direct sources of DHA and EPA, which are considered “essential fatty acids” (meaning, our body can’t produce them so we must get them from food or supplements).

What are the Benefits of Omega-3 Fatty Acids?

EPA and DHA can play a role in heart, brain, and eye health. A number of studies have shown that omega-3 consumption is inversely associated with cardiovascular disease (in simple words – a higher intake of omega-3 resulted in a lower incidence of cardiovascular disease). EPA is deemed to reduce the risk of blood clots which provides a cardioprotective effect. DHA also has links to heart health in addition to playing an important role in cognitive and visual development.

Long-term observational studies have demonstrated links between higher levels of EPA and DHA in the body and lower risks of cardiovascular disease, especially heart disease and heart attacks in the general population.

It has been proposed that EPA and DHA may offer protective effects on the heart by positively regulating a number of bodily functions like blood pressure, blood lipids, heart rate, inflammation and endothelial function (in other words, keeping our blood vessels healthy!).

A meta-analysis published in 2019, which included data from 13 studies, found statistically significant dose-response associations for numerous outcomes. “Dose-response” essentially means higher doses of marine omega-3 fatty acids resulted in better health outcomes (i.e. reduced risk factors).

Specifically, the results showed that marine omega-3 fatty acid consumption lowered the risk for coronary heart disease risk and death, cardiovascular disease risk and death and heart attacks.

How Much Omega-3 Should You Take?

The European Food Safety Authority (EFSA) stated in 2012 that “dietary recommendations for EPA and DHA based on cardiovascular risk considerations for European adults are between 250 and 500 mg/day”.

The American Heart Association recommends 1 to 2 seafood meals per week to reduce the risk of congestive heart failure, coronary heart disease, stroke and sudden cardiac death.

The British Dietetic Association recommend eating two portions of fish per week, one of which should be oily. If you are supplementing, they recommend one that provides you with the same amount of EPA and DHA as 1-2 portions of fish per week (about 450mg of EPA and DHA per daily dose).

As the recommended dose is very dependent on your individual needs, to figure out the best dose for you, speak to your doctor (they may not recommend any at all!).

Recent studies may be starting to suggest that a higher dose may not equate to more benefits. On the contrary, it could increase risk factors for certain disorders – check out point 4 in the next section.

Who Should Avoid Omega-3 Supplements?

Always consult your doctor before starting any supplements, especially if you are already taking medications as they may interact with each other.

Pregnant women:

You shouldn’t supplement with omega-3 from cod liver oil as these can contain high amounts of vitamin A which can be harmful to your unborn baby.

If you have liver disease:

Fish oil supplementation could potentially elevate the bleeding risk in individuals with liver scarring attributable to liver disease.

If you have diabetes:

High doses of fish oil may complicate the management of blood sugar levels for those with diabetes.

Irregular heartbeat risk:

A critical study in the omega-3 supplementation body of literature called REDUCE-IT found that Icosapent ethyl (IPE), a highly purified EPA ethyl ester, reduced cardiovascular death, myocardial infarction and stroke as well as other cardiac outcomes.

However, in the years after this trial, this study has been analysed further. Very recently (March 2023), a study conducted a post-hoc analysis using the data from the REDUCE-IT trial.

They found that patients in the IPE group had an increased risk of atrial fibrillation (AF) (a heart condition) hospitalization (3.1% IPE versus 2.1% placebo).

A meta-analysis in 2021 specifically looked at the risk of long-term omega-3 fatty acid supplementation and AF. They found that supplementing with marine omega-3 was linked to a higher likelihood of developing AF.

The risk seemed more pronounced in trials where doses exceeded 1g per day. This seems to be a common theme across many of the studies looking into the connection between AF and omega-3 supplementation (i.e. the risk is potentially more pronounced with higher doses).

Basic conclusions would be to avoid fish oil supplements if you are susceptible to, or at a higher risk of, AF.

Take a read of this article and this one too, it provides more insight on this topic.

Omega-3 from Fish Oil

Oily fish like mackerel and salmon are a rich source of omega-3s, containing up to 30% fatty acids. These include those essential long-chain polyunsaturated fatty acids like DHA and EPA. The NHS suggests at least two portions of cooked salmon per week for optimal health benefits.

Many individuals opt to supplement with fish oil, however, there are growing concerns about fish oil supplements’ purity due to their exposure to ocean pollutants during production. Research shows this could lead to potential contamination with substances which may impact bioavailability and absorption rates within the body.

In recent years, algae oil has emerged as an alternative source of EPA and DHA that could bypass some issues associated with fish oils. But how does it compare? Stay tuned as we delve deeper into this subject.

Algae Oil – A Plant-Based Source of Omega-3

Algae oil is a plant-based substance derived from marine algae and is a viable alternative to fish oils.

Algae oil has a high concentration of DHA, which may even exceed the levels found in many fish oils. Studies have shown that supplementation with algae oils can lead to significant increases in DHA levels even with relatively small doses over short periods. It’s also been suggested that algae oil increases DHA levels to a greater extent than other vegetarian alternatives like flaxseed and walnut oils.

Algae Oil vs Fish Oil

Okay, let’s compare some key nutritional aspects of algae oil and fish oil:

EPA and DHA

Fish oil contains both EPA and DHA, funnily enough, fish obtain EPA and DHA through consuming phytoplankton which in turn consume microalgae. As the fish eat the phytoplankton, the EPA and DHA build up in their tissue and are later extracted in fish oil.

Algae can contain both EPA and DHA but it usually contains either one or the other, depending on the strain. For that reason, algae oil is usually a mixture of different species to obtain the desired amounts of EPA and DHA.

Typically, studies have suggested that algae oil contains more DHA but less EPA than fish oil.

However, check out the below graph from a study which compares algae oil and krill oil (bearing in mind krill oil supplements have been shown to have greater EPA absorption than fish oil, so we’d expect it to smash algae oil out of the park):

This is the change in concentration of EPA when participants consumed a meal plus algae oil (the black squares) vs a meal plus krill oil (the diamonds).

Interesting right? The EPA concentration is much higher in the algae oil group over the course of the day compared to the krill oil group.

So then, if the EPA and DHA come directly from the algae, why aren’t more people supplementing with algae oil? It’s a good question, and the answer is difficult to pinpoint.

It could be because fish oil simply dominates the market, not many people are familiar with algae oil yet, especially as research is still ongoing. Another factor is price, algae oil can be quite expensive which can deter a lot of people.

Anti-inflammatory properties

A study published in the American Heart Association journal Circulation Research found fish oil supplements that contained a specific formula of omega-3 fatty acids reduced inflammation. The researchers found that fish oil supplementation increased anti-inflammatory molecules found in our blood for up to 24 hours.

It is important to point out, however, that a number of studies show no anti-inflammatory or beneficial effects of fish oil.

A 2021 study found that high doses of fish oil have no benefit in terms of reducing major cardiac events in high-risk people. We know omega-3’s from whole food sources like fish have some great health benefits but research specifically on fish oil supplements is less clear.

Algae oil has even less research but, of the research available, there are some promising signs. A recent study published in January 2023 showed that two types of algae oil helped protect the intestines of mice and lowered the inflammation response to antibiotic-induced damage. They also found an increase in “good” gut bacteria in the mice who received algae oils versus those who didn’t.

Note that this is in mice and cannot be applied directly to humans. It’s an interesting study but there is a need for much more research to be carried out on human subjects to truly understand the effects.

Bioavailability & Absorption

When it comes to omega-3 supplementation, the body’s ability to absorb and make use of its contents is a crucial consideration.

Most fish oils on the market typically contain fatty acids in the form of something called ethyl esters.

These can be harder for the body to break down, leading to lower absorption rates.

So why are they in this form?

Two main reasons…. one, it allows the manufacturer to create concentrated fish oil with high doses of DHA and EPA per serving. Raw fish oil contains minimal amounts of these two essential omega-3 fatty acids to have any meaningful effect.

Two, this process is essential as it removes any harmful contaminants. Despite this, concerns about contaminants might persist due to variations in manufacturing methods and quality control.

The bioavailability of ethyl ester fish oils is thought to be 70% less than natural triglyceride fish oil supplements. Our body has to work harder to access omega-3 when it’s delivered as ethyl esters. It is possible for manufacturers to convert the fish oil back to its natural triglyceride form but, as this adds cost to the process, the large majority don’t.

This study consistently showed that the absorption of EPA and DHA from fish oil in ethyl ester form was poor compared to re-esterified fish oil (which just means converting it back to natural triglycerides after adding the ethyl ester) and krill oil.

How about algae oil?

Research indicates that algae oil has a higher concentration of omega-3s, especially DHA, compared to fish oil.

A study by Arterburn et al (2008) showed that algae oil can be easier on our digestive system compared with many fish oils. The standout finding of this study was that algae oil supplementation and salmon both provided similar absorption rates of DHA – this suggests they may have impressive bioavailability and absorption properties.

It’s important to note though, that fresh salmon (and other fish) provide additional nutrients that algae oil supplementation does not. Nonetheless, the similar absorption rates are impressive!

Sustainability

Choosing algae oil over fish or krill oils can significantly contribute to environmental sustainability.

The process of growing algae for oil production is less demanding on marine ecosystems than traditional fishing practices. This makes it a more sustainable method for omega-3 fatty acid production, according to the American Oil Chemists’ Society.

Growing algae offers an environmentally friendly approach towards sustainable omega-3 fatty acid production. In contrast to traditional fishing or krill harvesting methods, this process has minimal impact on marine life and ecosystems.

Making an Informed Choice – Algae or Fish Oils…. or Neither?

Ideally, neither.

I would prefer you to be getting enough omega-3s from dietary sources such as cold-water fish (like salmon, mackerel and tuna), nuts and seeds (like chia seeds and flax seeds) or even vegetables like Brussels sprouts and spinach (these don’t contain quite as much omega-3 as the other foods mentioned but still a decent amount!).

 The recent studies surrounding the increased risk of atrial fibrillation from omega-3 supplementation really strengthen my “food first” approach.

Now, I am by no means concluding that this risk is high in everyone, nor I am trying to undermine the decades of research showing the potential benefits of omega-3 supplementation. In fact, even in one of the trials which showed an increased risk of atrial fibrillation, there were significantly more benefits (such as reduced risk of a stroke or a heart attack).

However, from my standpoint, why needlessly increase the risk of potential side effects if you can get enough omega-3 from whole foods?

After these new findings, a recent study from August 2023 looked at the risk of atrial fibrillation and dietary omega-3 intake, rather than omega-3 supplementation. The results were much more positive, in fact, they report an 11% decreased risk of atrial fibrillation at 750 mg a day of marine omega-3 fatty acids, followed by a plateau in the benefits at intakes higher than than this (rather than an increased risk).

It should be noted though, 91% of the 301,294 individuals whose data were used were men, and 84% were white. This makes it harder to generalise these results, nonetheless, it seems to be a positive indication that a whole-food-first approach may be beneficial.

If you have no risk factors, omega-3 supplementation may well be recommended to you. If you do have risk factors, such as diabetes or liver disease, work with your doctor to figure out the best approach for you.

If you follow a vegetarian or vegan diet (which may not contain enough DHA and EPA) or you are simply a more environmentally conscious consumer, then algae oil could be beneficial based on the current evidence.

Again, I must stress that there’s a lack of randomised controlled trials and review studies at the moment as algae oil is still a relatively new concept.

But, of the studies I have read, algae oil does seem promising. It seems to provide similar omega-3 content to fish oils, it’s a more sustainable and “cleaner” way of supplementation and it’s a primary source of omega-3 in the food chain (instead of fish which is considered a secondary source as they get their omega-3 from algae).

Whatever you decide to do, consult your doctor or healthcare professional first.