Docosahexaenoic acid properties

Characteristics and properties of docosahexaenoic acid (DHA)


Baked sardines

Baked sardines (soft cooking), with parsley. Very rich in proteins and healthy fats.

What is docosahexaeonic acid?

Docosahexaenoic acid, abbreviated as DHA (C22: 6) is a fatty acid that belongs to the group of fats omega 3, a polyunsaturated fatty acid.

It is not classified as an essential fatty acid because the body can synthesize DHA from linolenic acid (omega 3), which is essential. Therefore it is considered semi-essential.

DHA chemical structure

DHA is called in chemistry 22: 6n-3.

The structure of this fatty acid is formed by a chain of 22 carbon atoms containing 6 double bonds. It is represented as C20: 5.

It is also possible to synthesise docosahexaenoic acid DHA from eicosapentaenoic acid or EPA (C20: 5).

The synthesis of EPA to DHA is bidirectional, therefore, a contribution of EPA will propitiate the synthesis of DHA and vice versa.

The chemical molecular formula of docosahexaenoic acid (22: 6) is:

H3C-CH2-CH = CH-CH 2 -CH = CH-CH 2 -CH = CH-CH 2 -CH = CH- CH- (CH2) 2 -COOH


The effects of the fatty acid DHA, are concentrated in:

Vision Health and DHA

Fat DHA (docosahexaenoic acid) is essential for the regeneration and maintenance of a good state of visual tissues. Concretely it has a great influence on the retina.

It is recommended to eat a diet rich in this component in case of eye diseases, after a sight operation or in people who spend a lot of time in front of computer screens, mobile or tablets (dry eyes).

DHA for the nervous system

Eyes drawing

DHA is very important for the eyes and the brain because it constitutes 50% of the fats of the nervous system

Another important function of DHA is its role in the nervous system. This fat is part of up to 50% of the nervous tissue of the brain, so it is believed that good levels of this fatty acid will help improve brain function.

DHA-rich diets are recommended to prevent the occurrence of affections or diseases associated with the central nervous system and its cognitive functions, such as:

  • Alterations in character, since it regulates impulsivity.
  • Alterations in behavior, such as preventing the occurrence of attention deficit with or without associated hyperactivity.
  • Alterations in learning, such as preventing the onset of dyslexia and even autism.
  • It improves the synapse or neuronal connection, therefore it is recommended to people with difficulties to study.
  • Brain diseases such as depression, headache or migraine, can also have beneficial effects in degenerative brain diseases such as schizophrenia, dementia, Parkinson’s and Alzheimer’s.
  • A diet rich in DHA is related with an improvement of depression.

main properties of omega 3 DHA

Summary with the main properties of omega 3 DHA. Salmon is one of the richest foods in DHA

DHA to improve circulation

Related with improving circulation, DHA has the same effect as EPA, That is to say, it has hypotriglyceridemic and hypocholesterolemic effect.

A diet rich in foods that provide DHA will help lower levels of triglycerides and bad cholesterol LDL and VLDL in the blood.

One type of diet rich in this component is the DASH diet, used for the treatment of hypertension. The consumption of oily fish (which is the richest food in DHA) has been shown to improve hypertension and other heart problems, especially if it is accompanied by abundant vegetables and legumes consumption.

Obesity, weight looss and DHA requirements

Essential fatty acids DHA are needed during all stages of life, but it is recommended to increase their contribution in case of overweight, obesity and cholesterol problems.

Consuming foods rich in DHA helps prevent both heart and vascular diseases, from arteriosclerosis, to acute myocardial infarction or thrombosis.

DHA for pregnancy


During pregnancy, the needs of the DHA fatty acids are greatly increased.

To obtain the preventive effect of DHA, it should be provided along with a balanced diet, abundant in the feeding of pregnant and nursing, to ensure the proper development of the baby.

But not exclusively, that is, we must provide the necessary amount of this fatty acid in all stages of our life, whether high growth and development, as in the regeneration and maintenance of adulthood.

DHA anti-inflammatory properties

Theoretically, docosahexaenoic DHA fatty acid does not produce anti-inflammatory eicosanoids, unlike other omega 3 and 6 fatty acids: EPA, linoleic acid, linolenic acid and arachidonic acid.

But in the body, the liver is able to transform a part of DHA into EPA (another type of essential fatty acid in the family of omega 3), through bidirectional synthesis.

Prostaglandins, thromboxanes and leukotrienes manufactured from EPA (series 3), have slightly proinflammatory effects (regulators of inflammation), vasodilatory properties and antiplatelet properties in the body. Therefore, intake of DHA may have a positive effect on heart disease and inflammation.

It is possible to ingest DHA directly, since when they are inside the food rich in its content, they turn out to be more bioavailable than in the form of vegetable omega 3 (linolenic acid) and therefore, better and more easily absorbed and used by our organism than when is ingested through supplements.

Foods rich in fatty acids DHA

Foods rich in DHA are only of animal origin, as these fatty acids are produced by animals. The best sources are fatty fish:

Blue fish such as salmon, tuna, sardines, mackerel, etc.

– Fish oils (cod liver oil)

krill oil

– Functional foods, that is to say, products enriched with omega 3, specifically with EPA and DHA: eggs, dairy, margarine, etc.

The best way to cook or consume fish

Marinated sardines

During pregnancy, the needs of the DHA fatty acids are greatly increased.

To keep all of your omega-3, fish should be eaten properly.

Burning the fish or frying it degrades its healthy fats. Nor is it recommended to eat normally smoked salmon, which is very rich in carcinogenic nitrosamines, nor canned fish, which contains a lot of salt.

The best way to eat fish is grilled, baked at medium temperatures (below 175 ° C).

Another option is to consume it raw, previously macerated, like ceviche or sushi. To avoid poisoning by anisakis, fish should be frozen 48 hours before being prepared to consume it raw.

Vegetarian people and DHA

There are vegetarian DHA supplements that are extracted from algae concentrates. However, the consumption of algae in the form of food (vegetables of the sea) does not suppose a sufficient intake of DHA.

* More information: EPA and DHA for vegetarians

Who can have little DHA?

Alcohol, taking contraceptives, smoking and a diet with many bad fats decreases the body’s DHA synthesis.

DHA Supplements

Due to the multiple benefits of eating foods rich in omega 3 DHA, there are many supplements that incorporate DHA in its composition.

It is not highly recommended to consume DHA supplements, because what is really interesting is to take the foods that contain it, which provide more and better quality of these fatty acids.

foods and supplementos of DHA

Leaf with the content in omega 3 DHA of the salmon, the sardines and the supplements. Food is the best source of DHA

How to buy an omega 3 DHA supplements?

If we decide to buy an omega 3 supplement, we should look for the label to put “heavy metals free”, since many are extracted from large fish and concentrate the mercury they contain.

There are studies that, when analyzing the different supplements of omega 3 of the market, observed that some of them were rancid, that is to say, the fats had lost their healthy properties. As a precaution, it is recommended to check the expiration date and buy those supplements with the most expiring date (Fats will oxidize over time).

The recommended amount of DHA is about 400mg per bead, approximately (or higher).

* More information: Contraindications omega 3 supplements

Balance between omega 6 and omega 3

Fatty acids of the omega 6 family and those of the omega 3 family must remain in balance so that they act beneficially in our organism. The balance between them in the diet should hold a ratio of 3: 1 respectively. If the proportion of omega 6 is higher, will occur the effects cited, contrary to those of omega 3, due to the excess of arachidonic acid that would form.

Since they are polyunsaturated fatty acids and because of their composition, they are more susceptible than other types of fatty acids to become rancid because of oxidation. It is considered advisable to make a contribution of about 200 mg of vitamin E, which thanks to its antioxidant effect, prevents the occurrence of such oxidation reactions prematurely.

It is considered that a correct consumption of fatty acids of the omega 6 family is a good method of prevention against the appearance of pathologies very common in our society, such as obesity, atherosclerosis, which can trigger other cardiovascular diseases like acute myocardial infarction or a thrombosis.

* More information: Foods rich in essential fatty acids

Differences between vegetable omega 3 and fish oils

EPA and DHA have a high effectiveness because they do not require metabolic processes to be synthesized, unlike what happens with the intake of linolenic acid.

* Related information:

Low-fat diets

Types of fats

Low fat foods

High fat foods

punto rojo More information on fats.

Written by Editorial Botanical-online team in charge of content writing

19 March, 2019

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