Omega-3: Understand Its Purpose and Benefits

Published by Synlab on 10 July 2024

Omega-3 fatty acids are fats that play important roles in the structure of cell membranes and metabolic processes, as well as being necessary for maintaining brain function and nerve impulse transmission.

These substances are essential, meaning they need to be obtained through diet since our bodies are not always in optimal conditions to synthesize them.

Continue reading this article to learn:

What is omega-3?
What is the purpose of omega-3?
What diseases can omega-3 help prevent?
Benefits and drawbacks of omega-3;
Main dietary sources of omega-3;
How to know if your omega-3 levels are normal?

What is Omega-3?

Omega-3 fatty acids, known as n-3 fatty acids or ω-3 fatty acids (n-3 FAs), are heterogeneous groups of fatty acids with a double bond between the third and fourth carbon atoms from the methyl end (opposite the carboxyl end) (1).

Generally, we can distinguish between: monounsaturated fatty acids (MUFAs) — one double bond in the carbon chain.
Polyunsaturated fatty acids (PUFAs) — more than one double bond in the carbon chain.

It is assumed that all fatty acids with a double bond at the ω-3 carbon atom are omega-3 fatty acids.

Understanding More About the Effects of Omega-3 Fatty Acids

Polyunsaturated omega-3 fatty acids, including eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), offer a wide variety of benefits for a healthier life.

Epidemiological studies and clinical trials suggest a favorable effect of omega-3 consumption in reducing inflammatory symptoms, for example (2).

Many biological functions of PUFAs are mediated by bioactive metabolites produced by fatty acid oxygenases, such as cyclooxygenases (COXs), lipoxygenases (LOXs), and cytochrome P450 monooxygenases (CYPs) (3).

For example, arachidonic acid (AA) — an omega-6 fatty acid and a major component of phospholipids in the cell membrane — is released in response to inflammatory stimuli and plays a significant role in the production of eicosanoids.

It is believed that the anti-inflammatory effect of long-chain omega-3 occurs not only by competing with the formation of AA eicosanoids but also by providing alternative metabolites with less potent activity than AA-derived mediators.

Omega-3s like EPA, DPA, and DHA are also available at inflammation sites for enzymatic conversion into bioactive mediators (3).

What is the Purpose of Omega-3?

Monounsaturated, polyunsaturated, and subgroups of omega-3 fatty acids play an important role in the functioning of the body (1).

But what is the purpose of omega-3? Some monounsaturated omega-3s are precursors of pheromones in insects, while very long-chain polyunsaturated omega-3s are commonly found in the central nervous system and testicles of mammals, in spongy organisms, and are considered immunomodulatory agents (nutrients that act directly on the immune system).

Many of them are called essential because they cannot be synthesized by the body and must be obtained through the diet or produced by the body from linoleic and alpha-linolenic acids (1).

The “good” omega-3 is the long-chain one, and the less suitable one, with few health benefits, is short-chain fatty acids.

When questioning the purpose of omega-3, it is important to remember that a low level of this nutrient in the body is associated with an increased risk of cardiovascular or cerebrovascular episodes.

On the other hand, it has been shown that there is an association between increased consumption of these fatty acids and a lower predisposition to diseases such as depression or attention deficit hyperactivity disorder (ADHD). Its consumption is also essential during pregnancy and lactation for the proper neuronal development of the baby.

What Diseases Can Omega-3 Help Prevent?

The consumption of omega-3 is associated with various health benefits, such as:

Protection against cardiovascular diseases;
Improvement of blood pressure;
Reduction of triglycerides;
Anti-inflammatory effect;
Antithrombotic effect;
Antioxidant effect.

Recent studies have highlighted the beneficial effect of ω-3 fatty acids on Alzheimer’s Disease, which can be attributed to their antioxidant, anti-inflammatory, anti-apoptotic, and neurotrophic properties. The effect was obtained by individual consumption or by combining ω-3 fatty acids (4).

Omega-3, especially DHA and EPA, is known for its anticoagulant properties, meaning its action reduces the formation of blood clots, preventing platelet aggregation. Thus, they help prevent diseases such as deep vein thrombosis or pulmonary embolism.

Benefits and Drawbacks of Omega-3

Omega-3 is an essential nutrient for maintaining health and various vital functions. However, inadequate supplementation can cause harm to the body.

Next, we will explore the benefits of omega-3, as well as the potential side effects.

Omega-3 and Its Anti-inflammatory Effect

The anti-inflammatory effects of omega-3 are well-known, especially in the treatment of inflammatory bowel disease or rheumatoid arthritis, as it reduces the production of substances that stimulate this state, such as eicosanoids and cytokines. Additionally, this effect helps prevent cellular damage that can lead to cancer (5).

The anti-inflammatory effect can be attributed to the decreased level of cytokines and monocyte chemoattractant protein-1 by suppressing the nuclear factor kappa B. They can induce the expression of superoxide dismutase-2 mediated by the transcription factor nuclear erythroid 2-related factor, facilitating the antioxidant effect. Both DHA and EPA can increase the level of nerve growth factor (4).

Among the benefits of omega-3 through supplementation is the possible reduction of muscle inflammation caused by physical exercise, speeding up muscle recovery and reducing pain.

How Does Omega-3 Work in the Heart?

In the body, omega-3 fatty acids (mainly EPA and DHA) are incorporated into triglycerides as very low-density lipoprotein cholesterol (LDL) and released into the bloodstream (6).

Studies have shown that these fatty acids can help reduce inflammatory processes in atherosclerosis, minimizing pro-inflammatory stimuli and stimulating the resolution of inflammation (7), as well as offering benefits such as:

Improving cardiac muscle efficiency;
Reducing oxygen demand;
Controlling heart rate;
Reducing the risk of arrhythmias.

A study conducted in seven countries reported that mortality from ischemic heart disease is lower in Japan and Mediterranean countries than in the United States and northern European countries.

The results also highlighted the role of unsaturated fatty acids, abundant in Japanese and Mediterranean diets, showing a significant reduction in the relative risk of cardiovascular disease in people who consume omega-3 fatty acids (8).

Thus, omega-3 helps reduce “bad” cholesterol (LDL) and triglycerides (by 25-30%), responsible for forming fatty plaques in the arteries, promoting better permeability and functioning of the arteries, preventing heart attacks, arrhythmias, heart failure, and strokes.

Benefits of Omega-3 for the Brain

The normal physiological functioning of the neuronal membrane is highly dependent on its structure. One of the many factors that can influence its fluidity index is the lipid composition, in which cholesterol reduces membrane fluidity and polyunsaturated fatty acids (PUFA) increase it.

The brain can obtain long-chain PUFA directly from the diet, or it can use supplemented essential fatty acids (linoleic and alpha-linolenic) and convert them into longer-chain fatty acids. Omega-3 deficiency may be associated with reduced learning or memory capacity.

Docosahexaenoic acid (DHA) influences (9):

The physical properties of brain membranes;
The characteristics of their chemical receptors;
Cellular interactions;
Enzymatic activity.

As humans age, oxidative stress increases, responsible for reducing DHA and arachidonic acid (AA) levels in the brain. This process results in an increase in the proportion of cholesterol in the brain and occurs more intensely in Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis (10).

Oxidative stress is another relevant factor for normal membrane composition, inducing a decrease in its fluidity (11).

The incorporation of a restricted diet, such as supplementation by a particular ratio of omega-3/omega-6 PUFA mixture, provides many beneficial effects, such as reducing cholesterol levels and increasing PUFA levels in the neuronal membrane (12).

Additionally, among the benefits of omega-3 is the improvement of brain cell activity, leading to an increase in substances such as serotonin, dopamine, and norepinephrine, responsible for emotions, mood, and well-being, thus helping to prevent and aid in the treatment of depression.

Side Effects of Omega-3

Although extremely relevant for the human body, it is important to be aware of the possible harms of omega-3. Generally, supplementation of more than 3000 or 4000 mg per day is not recommended.

High doses of omega-3 can increase the risk of bleeding, especially in patients with clotting issues or those using medications such as aspirin, clopidogrel, ticlopidine, heparin, and warfarin.

From a dose of 3000 mg per day, side effects become more frequent and intense. Among the main harms of high doses of omega-3 are:

Nausea;
Diarrhea;
Abdominal cramps;
Risk of bleeding;
Increased LDL levels;
Excess gas;
Fishy breath.

Therefore, it is essential to consume omega-3 in moderation and, preferably, under medical guidance to avoid possible adverse effects.

Main Dietary Sources of Omega-3

The main foods containing omega-3, in descending order of concentration, are (13):

Animal sources: salmon, herring, sardines, tuna, anchovy, mackerel, whiting, whitefish, lambari, corvina;
Plant sources: flaxseed oil, flaxseed, chia seeds, canola oil, walnuts, soybean oil.

The recommended daily dose of omega-3 is about 250 to 500 mg but may vary according to age, as well as for pregnant and breastfeeding women.

Generally, supplement labels indicate the amount of EPA and DHA, and it is the sum of these two values that should give the total recommended daily amount.

What Test Does SYNLAB Offer for Omega-3?

SYNLAB offers the Omega-3 Index test, which through a blood sample, assesses the presence in the body of two of the main omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), obtained both through diet and by synthesis in your body from alpha-linolenic acid (ALA).

Subsequently, a calculation is made of the percentage that EPA and DHA constitute in relation to the total fatty acids present in the red blood cell membrane.

What Methodology is Used in the Omega-3 Index Test?

The Omega-3 Index test is performed using Gas Chromatography technology.

Gas chromatography (GC) is a technique for the separation and analysis of mixtures of volatile substances (14). This separation occurs through the differential interaction of its components, through the migration of the sample from a stationary phase via a fluid.

In this case, the sample is vaporized and introduced into a stream of an appropriate gas (mobile phase), which passes through a tube containing a chromatographic column (stationary phase) via an injection system, where the mixture is separated.

The components of the mixture are vaporized and, according to their properties, are retained and eluted through the column.

Who is the Omega-3 Index Test Indicated For?

SYNLAB’s Omega-3 Index test is indicated for:

People who want to proactively control their health;
Patients with cardiovascular diseases;
Patients with chronic diseases, including asthma, metabolic, immune, or inflammatory disorders;
Patients with low mood or depression;
Patients with neurological diseases;
Children suspected of having attention deficit hyperactivity disorder (ADHD);
During pregnancy, to ensure proper nutritional intake for the baby.

Get to Know the SYNLAB Group

Accurate and up-to-date tests are essential for making more assertive diagnoses and better guiding treatments. SYNLAB is here to help you.

We offer diagnostic solutions with rigorous quality control for the companies, patients, and doctors we serve. We have been in Brazil for over 10 years, operate in 36 countries and three continents, and are leaders in providing services in Europe.

Contact the SYNLAB team and learn about the Omega-3 Index test!

REFERENCES

1. CHOLEWSKI, M.; TOMCZYKOWA, M.; TOMCZYK, M. A Comprehensive Review of Chemistry, Sources and Bioavailability of Omega-3 Fatty Acids. Nutrients, v. 10, n. 11, p. 1662, 4 nov. 2018.

2. CALDER, P. C. Omega-3 polyunsaturated fatty acids and inflammatory processes: nutrition or pharmacology? British Journal of Clinical Pharmacology, v. 75, n. 3, p. 645–662, 5 fev. 2013.

3. Serhan CN. Pro-resolving lipid mediators are leads for resolution physiology. Nature. 2014 Jun 5;510(7503):92-101.

4. AJITH, T. A. A Recent Update on the Effects of Omega-3 Fatty Acids in Alzheimer’s Disease. Current Clinical Pharmacology, v. 13, n. 4, p. 252–260, 14 jan. 2019.

5. JOURIS, K. B.; MCDANIEL, J. L.; WEISS, E. P. The Effect of Omega-3 Fatty Acid Supplementation on the Inflammatory Response to eccentric strength exercise. Journal of Sports Science & Medicine, v. 10, n. 3, p. 432–438, 2011.

6. MASSON, S. et al. Incorporation and washout of n-3 polyunsaturated fatty acids after diet supplementation in clinical studies. Journal of Cardiovascular Medicine, v. 8, n. Suppl 1, p. S4–S10, set. 2007.

7. BÄCK, M. Omega-3 fatty acids in atherosclerosis and coronary artery disease. Future Science OA, v. 3, n. 4, p. FSO236, nov. 2017.

8. KIMURA, N.; KEYS, A. Coronary heart disease in seven countries. X. Rural southern Japan. Circulation, v. 41, n. 4 Suppl, p. I101-112, 1 abr. 1970.

9. YEHUDA, S. et al. The role of polyunsaturated fatty acids in restoring the aging neuronal membrane. Neurobiology of Aging, v. 23, n. 5, p. 843–853, 1 set. 2002.

10. SIMONIAN, N. A.; COYLE, J. T. Oxidative Stress in Neurodegenerative Diseases. Annual Review of Pharmacology and Toxicology, v. 36, n. 1, p. 83–106, abr. 1996.

11. JOSEPH, J. A. et al. AGE-RELATED NEURODEGENERATION AND OXIDATIVE STRESS. Neurologic Clinics, v. 16, n. 3, p. 747–755, ago. 1998.

12. YEHUDA, S.; RABINOVITZ, S.; MOSTOFSKY, D. I. Essential fatty acids are mediators of brain biochemistry and cognitive functions. Journal of Neuroscience Research, v. 56, n. 6, p. 565–570, 15 jun. 1999.

13. LANUTRI, A. Ômega 3 – Fontes Alimentares. Disponível em: <https://lanutri.injc.ufrj.br/2019/12/09/omega-3-fontes-alimentares/>.

14. Ceatox – CROMATOGRAFIA A GÁS. Disponível em: <https://ceatox.ibb.unesp.br/padrao.php?id=12>.