Omega 3: benefits, contraindications, where they are found

Omega 3: benefits, contraindications, where they are found

What is
What are they for
Where are Omega-3s found

What are Omega-3s

Omega-3s are polyunsaturated fatty acids defined as "essential" because our body is unable to produce them independently and it is necessary to introduce them with food.

They fall within the nutritional class of lipids and they are called "polyunsaturated" because in their structure there are several double bonds between the carbon atoms.

We find the first double bond right at the third carbon atom, which is why they are called Omega-3.

This group includes three different molecules:

  1. Α-linolenic acid
  2. Eicosapentaenoic acid (EPA) 
  3. Docosaenoic acid (DHA)

Even the Omega-6 they are essential polyunsaturated fatty acids, but in this case the first double bond is positioned at the sixth carbon atom.

Compared to Omega-3s, Omega-6s seem to be more present in the Western diet and this would lead to an imbalance in the omega-3 / omega-6 ratio which, as we will see, can lead to a greater risk of getting sick.

Fatty acids they are almost never found in free form in nature, but fall within the composition of more complex molecules, including:

  • Triglycerides: made up of one glycerol molecule and three fatty acid molecules.
  • Phospholipids: formed by one molecule of glycerol, one of phosphoric acid and two of fatty acids.


What are Omega-3s for

  • Energy role: they provide 9 calories / g (more than double compared to proteins and carbohydrates) and can be stored in the form of triglycerides in the cells of the adipose tissue, from which the body derives its energy through the oxidation of fatty acids, in case of need .
  • Structural role: fatty acids are the main constituent of cell membranes, confer protection and support to organs and play specific roles in highly specialized tissues, such as myelin of nervous tissue.
  • Functional role: omega-3 and omega-6 are precursors of important molecules, eicosanoids. In particular, while omega 3s favor the production of anti-inflammatory eicosanoids, omega 6s can also induce the production of proinflammatory eicosanoids. This is why it is important that there is always the right balance between the two types of fatty acids.

An excess of omega 6 is associated with a greater inflammatory state which, if chronic, could increase the risk of getting sick.

Inflammation, in fact, is the main cause of the onset of chronic diseases, therefore, due to their anti-inflammatory properties, omega-3s are useful in preventing:

  • Cardiovascular diseases (they reduce blood pressure, platelet aggregation and triglycerides, increase good cholesterol).
  • Inflammatory diseases, such as rheumatoid arthritis, Chron's disease and ulcerative colitis.
  • Neurodegenerative diseases, anxiety, depression and behavioral disturbances.
  • Cognitive impairment and abnormal brain development during pregnancy.
  • Autoimmune diseases.
  • Diseases of the eye, such as macular degeneration.
  • Insomnia.

Where are omega 3s found

As we have seen, a deficiency in omega-3 fatty acids may be related to an increased risk of some diseases, especially cardiovascular, neurodegenerative and autoimmune.

It's important introduce the right amount through food, as our body is unable to self-produce them.

According to the LARN (Reference levels of intake for the population and the country) an adult should take about 250 mg per day. Where can we find them?

The omega-3s DHA and EPA are found mainly in blue fish, such as salmon, anchovies, sardines and mackerel, while ALA is found in plant foods, including flax seeds, chia seeds, and walnuts.
Consuming these foods regularly in the recommended quantities is sufficient to meet the omega-3 requirement and there is no need for any supplementation.

Today the market offers a large variety of omega-3 supplements, especially based on fish oil, which can be useful only in case of deficiencies or non-consumption of the foods mentioned.

In fact, some studies have observed how a surplus of omega-3s taken through supplementation has no additional effect.


To date there are no contraindications for Omega-3s, however there are possible effects due to an overdose and it is recommended to do be careful in those who are being treated with anticoagulant drugs as they could enhance its effect.


More in-depth articles on Omega-3s

10 foods rich in healthy fats
The 10 benefits of chia seeds, rich in omega 3
Foods and omega 3 fatty acids
Seasonal allergy: let's also treat ourselves with omega 3
The seeds that contain essential fatty acids
Linseed oil, a mine of omega 3
Do Omega 3 Help You Lose Weight?
Omega 3 supplements in pregnancy
Foods rich in omega 3 against brain aging
Cod liver oil rich in omega 3: price and where to buy it
Omega 3 for weight loss
The main sources of Omega 3
Omega 3 and chronic bronchitis 


Bibliography and sources

Docosahexaenoic acid is the preferred dietary n-3 fatty acid for the development of the brain and retina, Pediatric Research 
Circulating Omega-3 Fatty Acids and Neovascular Age-Related Macular Degeneration, IOVS
Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children's IQ at 4 years of age, Pediatrics 
Maternal consumption of a docosahexaenoic acid-containing functional food during pregnancy: benefit for infant performance on problem-solving but not on recognition memory tasks at age 9 mo, The America Journal of Clinical Nutrition
Age- and dose-dependent effects of an eicosapentaenoic acid-rich oil on cardiovascular risk factors in healthy male subjects, Atherosclerosis
Moderate consumption of fatty fish reduces diastolic blood pressure in overweight and obese European young adults during energy restriction, Nutrition
Benefits of fish oil supplementation in hyperlipidemia: a systematic review and meta-analysis, International Journal of Cardiology
Omega-3 fatty acids in the maintenance of ulcerative colitis, JRSM
Fish consumption, long-chain omega-3 fatty acids and risk of cognitive decline or Alzheimer disease: a complex association, Nature Reviews Neurology
Eicosapentaenoic acid versus docosahexaenoic acid in mild-to-moderate depression: A randomized, double-blind, placebo-controlled trial, European Neuropsychopharmacology
Comparison of therapeutic effects of omega-3 fatty acid eicosapentaenoic acid and fluoxetine, separately and in combination, in major depressive disorder, Australian and New Zealand Journal of Psychiatry
Omega‐3 fatty acids for the primary and secondary prevention of cardiovascular disease, Cochrane Library
Food composition tables, CREA


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