EPA and DHA: the ratio explained

Two letter abbreviations appear on almost every omega-3 product: EPA and DHA. One oil promotes a high DHA content, the next a high EPA content – and before long you're standing in front of the shelf, puzzled, wondering which ratio is actually the „right“ one. The honest and reassuring answer: there is no universal ideal ratio. What matters more is understanding what the two fatty acids do in the body and which approved claims are tied to which amount.

The short answer: DHA is a key building block of the brain and retina – there are dedicated DHA claims for brain function and vision (from 250 mg DHA/day). EPA and DHA together contribute to normal heart function from 250 mg per day. Rather than fixating on an exact ratio, it's best to decide based on your goal and check whether you're reaching the absolute amount required in each case.

What EPA and DHA are in the body – the mechanism

Both belong to the omega-3 family of fatty acids and are long-chain, polyunsaturated fatty acids. They are found mainly in oily sea fish and in microalgae – with the algae being the original source: the fatty acids only reach the fish via the food chain. DHA (docosahexaenoic acid) is particularly long and flexible; it occurs in high concentrations in the cell membranes of the brain and retina, where it keeps the membranes supple and helps shape the function of the nerve and visual cells. EPA (eicosapentaenoic acid) is somewhat shorter and serves the body, among other things, as a starting material for a range of signalling substances that help regulate various metabolic processes. Both are important and are supplied through food or supplementation.

Which claims are approved for EPA and DHA

In the EU, only clearly defined health claims may be used. For the two fatty acids, the following apply:

Important: for heart function, EPA and DHA count together; for brain and vision, DHA is specifically the relevant one. This is exactly what explains why the ratio matters depending on your goal.

Where EPA and DHA sit within the fatty-acid family

A quick look at the bigger picture helps. Omega-3 is one of several families of polyunsaturated fatty acids; alongside it there is, for example, the omega-6 family. Within the omega-3 group, a distinction is made between the plant-based, short-chain fatty acid ALA and the long-chain members EPA and DHA. ALA is the „precursor“, while EPA and DHA are the long-chain forms to which most approved claims refer. So when you read „omega-3“, it's worth checking which fatty acid is meant – for heart, brain and vision, only EPA and DHA count, not ALA.

What the research is investigating

Research around EPA and DHA is very active. Among other things, scientists are investigating how the two fatty acids differ in their roles – for example DHA as a structural building block of nervous tissue and the retina, versus EPA as a starting material for certain signalling molecules. The question of which profile is favourable in which context is also being discussed. What is firmly established textbook knowledge is the role of DHA as a main component of the brain's grey matter and of the photoreceptors in the eye. Much beyond that is the subject of ongoing research – fascinating, but not (yet) conclusive. We don't derive any promises of efficacy from this; we stick to the approved claims above.

Is there an ideal ratio?

There is no single EPA-to-DHA ratio that is „perfect“ for everyone. Which split makes sense depends on your goal and on the source:

• DHA-focused products are of interest if the approved DHA claims on brain function and vision matter to you. Pure algae oil is often naturally rich in DHA.
• EPA-focused or balanced products are often chosen when the focus is broader.
• Combinations with similar amounts of EPA and DHA cover both areas.

Rather than getting hung up on a particular ratio, it's worth looking at the absolute amounts: are you reaching the 250 mg for the respective effect? How to check this on the label is shown in Omega-3: how much per day?.

Can the body convert EPA and DHA?

To a limited extent, yes. From the plant-based omega-3 fatty acid ALA (alpha-linolenic acid), the body produces some EPA and – to a lesser degree – DHA. This conversion is, however, inefficient and for many people isn't enough to meet requirements through ALA-rich oils such as linseed oil alone. How well it works depends on individual factors and is slowed by a diet very high in omega-6, because both fatty-acid families compete for the same enzymes. Converted to DHA, usually only a little remains from ALA.

That's why direct EPA/DHA sources such as oily fish or algae oil are so popular – they supply both fatty acids ready-made. Those on a plant-based diet therefore like to reach for algae oil for a reliable DHA supply. More on comparing plant-based and animal sources in Linseed oil vs. fish oil (omega-3) and Fish oil vs. algae oil.

Natural ratios in different sources

The EPA-to-DHA ratio varies naturally – and that helps with the choice:

This explains why many vegan algae oils are naturally rich in DHA – of interest if the DHA claims matter to you. The differences are examined in Fish oil vs. algae oil.

What research investigates separately for EPA and DHA

Because EPA and DHA play different roles in the body, research increasingly looks at them individually rather than just at „omega-3“ as an umbrella term. For example, scientists investigate how strongly DHA is incorporated as a structural building block into nervous tissue and the retina and how this changes over the lifespan, or which signalling substances arise from EPA. Established textbook knowledge here is that DHA is, by quantity, the dominant omega-3 fatty acid in the brain. Much regarding the finer differences, however, is still the subject of ongoing studies – one more reason to be guided, when buying, by the clearly approved claims and the absolute amounts rather than by grand promises. How to place your overall status is shown in The omega-3 index explained simply.

A practical example: which product for whom?

Imagine three people. The student who studies a lot at the screen and values the approved DHA claims on brain and vision naturally reaches for a DHA-focused algae oil with at least 250 mg DHA per daily serving. The recreational athlete, whose interest is more broadly about heart function, chooses a balanced product that together reaches the 250 mg of EPA+DHA. The vegan, who eats no fish at all, most likes to combine both in an algae oil with a stated EPA and DHA content. In all three cases, it isn't the magic ratio figure that decides, but whether the relevant amount is reached. Fitting alongside: Covering omega-3 on a vegan diet.

Which ratio for which goal?

A rough orientation, without promises of efficacy:

• Focus on brain and vision: here DHA is the relevant one. A DHA-focused product that supplies at least 250 mg DHA per day is the obvious choice.
• Focus on heart function: for this, EPA and DHA count together from 250 mg – a balanced or combined profile covers this well.
• All-rounder: anyone wanting to cover both areas reaches for a product with both fatty acids in sufficient amounts.

In the end, what matters is less the exact numerical ratio than whether you reach the necessary amount. How much that is, is clarified in Omega-3: how much per day?.

Honestly put in context

Established and approved: the heart claim for EPA+DHA and the brain/vision claims for DHA, from 250 mg each. Textbook knowledge: DHA is a structural building block of the brain and retina. Open and under research: which exact ratio is optimal in which context. In practical terms this means: be guided by your goal and the absolute amount, not by a magic ratio figure. How well you're supplied can be estimated via the omega-3 index – see The omega-3 index explained simply.

Matching products from Scheunengut

In the Algae category you'll find algae oil that is naturally rich in DHA and, depending on the product, also contains EPA – with clearly stated amounts. If your focus is on heart function, take a look at Heart & Circulation; if the DHA claims on brain and concentration are on your mind, see Brain & Nerves. Further reading to match: Omega-3: how much per day?, The omega-3 index explained, Fish oil vs. algae oil, Linseed oil vs. fish oil and Covering omega-3 on a vegan diet.

Frequently asked questions (FAQ)

What is the difference between EPA and DHA?

Both are long-chain omega-3 fatty acids. DHA is particularly long and a key structural building block of the brain and retina; EPA is somewhat shorter and serves as a starting material for various signalling substances. For heart function, both count together; for brain and vision, DHA specifically is the relevant one.

Which EPA-DHA ratio is the best?

There is no universally best ratio – it depends on your goal and the source. More important than the ratio figure is whether you reach the absolute amounts: from 250 mg EPA+DHA for heart function, from 250 mg DHA for brain and vision.

Is algae oil more EPA- or DHA-rich?

Algae oil is often naturally DHA-focused, and some products additionally supply EPA. That makes it interesting if the approved DHA claims on brain function and vision matter to you. Pay attention to the stated EPA/DHA amounts per serving.

Can the body convert EPA into DHA?

To a limited extent, the body forms some EPA and less DHA from the plant-based fatty acid ALA. This conversion is, however, inefficient and often isn't enough. That's why direct sources such as fish or algae oil are more reliable for supplying EPA and DHA ready-made.