Omega-3 is one of the best-known nutrients when we talk about healthy eating, well-being and supplementation. However, the term “omega-3” includes different fatty acids, and they do not all come from the same sources or perform exactly the same roles in the body.
Understanding the benefits of omega-3 means distinguishing between ALA, EPA and DHA, understanding what we can obtain through food and knowing what to check before choosing a supplement.
As with other nutrients, the aim should not be to look for a miracle solution, but to make sure our diet provides adequate amounts and consider supplementation when it makes sense.
What is omega-3?
Omega-3s are a family of polyunsaturated fatty acids that form part of our diet and are involved in different functions in the body.
When talking about omega-3, it is useful to distinguish mainly between three types: ALA, EPA and DHA.
Alpha-linolenic acid, or ALA, is an essential fatty acid, which means that our body cannot produce enough of it and we therefore need to obtain it through food.
EPA and DHA are long-chain omega-3 fatty acids found mainly in oily fish, seafood and certain marine oils. They can also be obtained through supplements made from microalgae.
ALA, EPA and DHA: what is the difference?
ALA or alpha-linolenic acid
ALA is found mainly in plant-based foods.
It can be found, for example, in flaxseeds, chia seeds, walnuts and certain vegetable oils.
Our body can convert some ALA into EPA and subsequently into DHA, but this conversion is limited.
For this reason, eating foods rich in ALA can be valuable as part of a balanced diet, but it should not necessarily be considered equivalent to obtaining EPA and DHA directly.
EPA or eicosapentaenoic acid
EPA is one of the main long-chain omega-3 fatty acids found in fish and marine oils.
It is commonly found together with DHA both in foods and in fish oil supplements.
In the European Union, EPA and DHA are recognised as contributing to the normal function of the heart when the established conditions for this claim are met.
DHA or docosahexaenoic acid
DHA is another important long-chain omega-3 fatty acid.
In addition to contributing together with EPA to normal heart function, DHA contributes to the maintenance of normal brain function and normal vision when consumed in the established amounts.
This does not mean that consuming larger amounts will automatically improve intellectual ability, eyesight or provide protection against disease.
These claims refer to the maintenance of normal physiological functions.
Main benefits and functions of omega-3
EPA and DHA contribute to normal heart function
This is probably one of the best-known properties of omega-3 fatty acids.
EPA and DHA contribute to the normal function of the heart. The beneficial effect is obtained with a daily intake of 250 mg of EPA and DHA.
This helps explain why oily fish and foods that provide these fatty acids are commonly included in healthy eating recommendations.
However, when talking about cardiovascular health, we need to consider our overall diet and lifestyle.
Maintaining a balanced diet, being physically active on a regular basis, avoiding smoking and taking care of other healthy habits remains far more important than relying on a single nutrient for cardiovascular well-being.
DHA contributes to the maintenance of normal brain function
DHA is present in important structures in the body, including the brain.
DHA is recognised as contributing to the maintenance of normal brain function when the established conditions of consumption are met.
This does not mean that a DHA supplement will automatically increase memory, intelligence or concentration.
Brain function depends on many factors and should be understood within the broader context of our health, diet, rest and daily habits.
DHA contributes to the maintenance of normal vision
Another recognised function of DHA relates to vision.
DHA contributes to the maintenance of normal vision, but once again we are talking about a normal physiological function and not a treatment for correcting vision problems.
This distinction is important because it allows us to discuss nutrition accurately without turning food supplements into medicines.
Which foods contain omega-3?
Food should always be our first starting point.
The main sources vary depending on the type of omega-3:
- Oily fish: sardines, mackerel, salmon, herring and other fish provide EPA and DHA.
- Seafood: certain species also provide long-chain omega-3 fatty acids.
- Flaxseeds and chia seeds: these are particularly well-known plant sources of ALA.
- Walnuts: provide ALA as part of a varied diet.
- Vegetable oils: some oils contain relevant amounts of ALA.
- Microalgae: can be used as a source of DHA and, depending on the product, also EPA.
This makes it possible to adapt omega-3 sources to different types of diet.
People following vegetarian or vegan diets, for example, can obtain ALA from different plant foods and can also find DHA or EPA+DHA supplements derived from microalgae.
Is plant-based omega-3 the same as EPA and DHA?
Not exactly.
Plant-based omega-3 is usually found mainly in the form of ALA.
Our body can convert ALA into EPA and DHA, but this conversion is limited, particularly in the case of DHA.
For this reason, when assessing our omega-3 intake, it is important to know which type we are consuming rather than looking only at the term “omega-3”.
A food rich in ALA can certainly form part of a healthy diet, but nutritionally it is not exactly the same as a direct source of EPA and DHA.
How much EPA and DHA do we need?
An adequate intake of 250 mg of combined EPA and DHA per day has been established for adults.
This amount serves as a general nutritional reference and also corresponds to the quantity associated with the beneficial effect of EPA and DHA on normal heart function.
This does not mean that everyone needs to take a supplement to reach this amount.
Food can provide EPA and DHA, particularly when fish is eaten regularly.
Whether supplementation is needed will therefore depend on our eating habits, personal requirements and individual circumstances.
When can an omega-3 supplement make sense?
A supplement may be an option when our diet provides only small amounts of EPA and DHA or when our dietary preferences make it difficult to obtain them regularly.
For example, someone who eats little or no fish may consider alternative sources of these fatty acids.
For people following a vegetarian or vegan diet, microalgae-derived supplements are available that provide DHA and, in some formulations, EPA as well.
However, supplementation does not mean taking the largest possible amount.
The appropriate dose depends on the composition of the product, our diet and our personal circumstances.
If you have a medical condition, are pregnant, take medication or have specific nutritional requirements, it is advisable to consult a healthcare professional.
How to choose a good omega-3 supplement
This is probably one of the most important sections, because two products that prominently display “1000 mg fish oil” can provide very different amounts of EPA and DHA.
Do not look only at the amount of oil
The total amount of fish oil is not necessarily the amount of omega-3 we are consuming.
For example, a capsule may contain a certain amount of oil, but only part of that oil will consist of EPA and DHA.
Therefore, when comparing products, we should check the nutritional information to see how many milligrams of EPA and DHA the recommended serving actually provides.
Check the full daily serving
Another common mistake is to look at the amount shown for one capsule when the recommended daily serving may consist of two or more capsules.
Always check how much EPA and DHA is provided by the complete daily serving recommended by the manufacturer.
Check the source
Supplements can come from different sources.
Fish oil is one of the most common, while oils obtained from microalgae provide an especially interesting alternative for people looking for a non-animal source.
The source should be clearly identified on the product label.
Review the complete formulation
As we discussed when looking at magnesium supplements, we should not choose a product simply because of the largest number shown on the packaging.
It is important to check the actual amount of the nutrient, the daily serving, additional ingredients and directions for use.
Fish oil or algae oil?
Both options can provide long-chain omega-3 fatty acids, although their origins are different.
Fish oil supplements commonly provide EPA and DHA in different proportions.
Oils derived from microalgae are used particularly as a source of DHA, and some formulations also provide EPA.
This makes microalgae an especially useful alternative for vegetarians, vegans or anyone who simply prefers to avoid fish-derived products.
The choice should be based mainly on the actual amount of EPA and DHA provided by the product, as well as on our individual needs and preferences.
When is the best time to take omega-3?
There is no single mandatory time of day for taking an omega-3 supplement.
In practice, it is often convenient to include it with one of our meals and maintain a routine that makes consistency easier.
The most important thing is to follow the recommended serving and the manufacturer's instructions.
If digestive discomfort occurs, it may also be useful to review when the supplement is taken and the specific directions provided with the product.
Does more omega-3 mean more benefits?
No.
This principle is important with almost every type of supplementation.
The fact that a nutrient is necessary does not mean that consuming increasingly larger amounts will produce increasingly greater benefits.
Omega-3 supplements can cause digestive discomfort in some people, and high doses require particular caution, especially when certain medical treatments are involved.
If you take medicines that affect blood clotting, have a medical condition or need to use high doses for a specific reason, you should consult a healthcare professional beforehand.
Omega-3, diet and lifestyle
It is easy to focus all our attention on which supplement to buy and forget what matters most.
Our well-being depends on our habits as a whole.
A varied diet, doing regular physical exercise, getting adequate rest and maintaining sustainable habits makes far more sense than relying on a single food supplement.
Omega-3 can form part of that nutritional strategy, but it should not be used to compensate for an unbalanced diet or an unhealthy lifestyle.
Omega-3: important, without turning it into a miracle product
The benefits of omega-3 are linked to specific functions of particular fatty acids.
EPA and DHA contribute to normal heart function, while DHA contributes to the maintenance of normal brain function and normal vision.
At the same time, we need to distinguish ALA, which is mainly plant-derived, from the long-chain omega-3 fatty acids EPA and DHA, and understand that they are not simply different names for exactly the same thing.
If we decide to use a supplement, it is worth looking beyond the words “fish oil” or the large number displayed on the front of the packaging.
The information that really matters is the amount of EPA and DHA provided by the daily serving, the source, the complete formulation and the directions for use.
Once again, supplementation makes much more sense when it is used to complement healthy habits and a balanced diet, rather than replace them.