Omega-3: Uses, Health Benefits & Side Effects

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Omega-3 is an essential nutrient for the optimal functioning of the body. It is also quite popular as a dietary supplement.

10% of American adults take omega-3 supplements due to the various health benefits attributed to it. These health benefits range from preserving your heart’s health to aiding in mental health and preventing autoimmune diseases.

That omega-3 is good for you is an undisputed fact. But the question is, can it keep all the above ailments at bay?

In this Omega-3 crash course, we set popular views aside and turn to science for answers. We highlight the most popularized omega-3 benefits and weigh them against the scientific research conducted on the same.

We also have an overview of omega-3, its daily recommended dose, possible side effects, and its safety factor.

What is Omega-3?

Omega-3 are a group of essential fatty acids found in fish and various plant food sources. Essential fatty acids are not made by the human body but are necessary for its functions; they are acquired through diet (1)

There are three types of omega-3 fatty acids; eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). EPA and DHA amino acids are sourced from fish, while ALA is present in some plant foods (2).

Coldwater fish are the best sources of omega-3. They include; tuna, salmon, sardine, lake trout, anchovy, bluefish, halibut, striped bass, and herring.

If you are vegan, vegetarian, or are averse to fish, you can get omega-3 from plant food sources. These include; walnuts, chia seeds, hemp seeds, seaweed, and flax seeds.

Note, however, that the fish sources are richer in omega-3 than plant sources (3). The ALA form of omega-3 present in plants can be converted to EPA and DHA forms but at low rates.

Omega-3 fatty acids form part of the cell membrane in every cell in the human body. The incorporation of omega-3 fatty acid to the cell membrane makes it essential for body functions like cell growth (4) (5).

Is Omega-3 Safe?

Omega 3 is generally considered safe and well-tolerated among different users. In 2004, the FDA approved the consumption of foods and supplements containing EPA and DHA omega-3 fatty acids (6).

It also approved the use of omega-3 in adjunctive or secondary therapy for persons with elevated triglyceride levels (7). Triglycerides are excess calories stored in your adipose tissue as excess fats or lipids (8).

However, omega-3 is not without its cons. Omega-3 may trigger mild side effects in some people which we will highlight later on.

Some studies have linked long-chain fatty acids like omega-3 with increased risk of prostate cancer in men. Others, however, have yielded contradictory results (9).

There are also conflicting data on whether people who are allergic to fish can take omega-3 supplements. The best thing would be to consult your doctor before you start taking omega-3 supplements.

Omega-3 Health Benefits-min

Omega-3 Health Benefits

As previously stated, omega-3 rich foods and supplements are popular because of omega-3’s health benefits. So, which benefits are factual, and which ones are a farce?

Below we take a look at each popular benefit of omega-3 and level it against scientific research on the subject. Note that most existing research data on omega 3 is based on the EPA and DHA forms of omega 3.

Let us kick off with the health benefits.

1. Reduce the risk of cardiovascular disease

Omega-3 has a myriad of benefits to the cardiovascular system. These include lowering blood pressure, lowering the risk of stroke and heart attack, and lowering triglyceride levels.

What science says

The cardiovascular system is quite elaborate. To thoroughly explore the benefits of omega-3 to the cardiovascular system, we have to independently look at each benefit.

  • Lowering blood pressure

There have been several studies on the effects of fish oil and omega-3 supplements on blood pressure. Normal blood pressure should read a systolic figure (numerator) below 120 and a diastolic figure (denominator) below 80, i.e., 120/80.

Systolic blood pressure is a more critical marker of the risk of cardiovascular disease. However, an elevation of both the systolic and diastolic figure is indicative of high blood pressure or hypertension.

A series of placebo-controlled studies were conducted on persons with risk factors of hypertension, such as diabetes. The participants ranged in risk factors from low to high.

The studies showed that omega-3 and fish oil significantly reduced both diastolic and systolic pressure. The effect was more profound in participants with more significant risk factors for cardiovascular disease (10) (11).

  • Lowering triglycerides levels

The average triglyceride concentration in the blood is 150m/dl of blood; anything above that is high. When triglyceride levels are high, the excess fat is deposited along the arterial walls and causes the arteries to harden (12).

The arteries’ loss of elasticity can lead to adverse and fatal heart conditions like stroke and heart attack.

Various research studies conducted on both humans and animals suggest the efficacy of omega-3 in lowering triglyceride blood plasma levels (13) (14).

The studies went a step further and identified the mechanism of action by which omega-3 lowered triglyceride levels.

First, omega-3 inhibits the delivery of non-esterified fatty acids (NEFA) to the liver. The liver uses NEFA to synthesize triglycerides (15).

Omega-3 also increases beta-oxidation, which is the breakdown of fats in the adipose tissue to an enzyme necessary for biochemical reactions (16).

2. Reduced risk of blood clots

There is a belief that Omega 3 can combat blood clots that may occur in the arteries and cause life-threatening conditions.

What Science Says

When we get an injury that causes bleeding, either outside or inside the body, blood clot formation prevents excessive bleeding.

The platelet cells in the blood are the first responders in case of bleeding. They initiate a process called hemostasis, whereby the blood flow rate slows down to facilitate the clotting process (17).

However, excess platelet activity leads to the formation of a thrombus, a type of blood clot that blocks the arteries (18). Thrombi causes diverse cardiovascular diseases and conditions like heart attack, stroke, thrombosis, and atherosclerosis.

As previously stated, the cell membranes of all body cells consist of omega-3; including blood platelets. Note, however, that the omega-3 composition varies with the omega-3 composition per individual.

Various research studies suggest that omega-3 on the platelet cell membrane regulates platelet activity and inhibits thrombin formation (19) (20). By regulating clotting, omega-3 also lowers the risk of acute cardiovascular diseases.

3. Lowers the risk of inflammation

Omega-3 can also reduce inflammation, which may otherwise lead to chronic illnesses like diabetes, arthritis, and cancer.

What Science Says

Inflammation is the action triggered by our immune system in response to a foreign body such as a pathogen. Just like clotting above, inflammation is necessary for our health but detrimental when it goes rogue.

One negative effect of inflammation is with autoimmune diseases whereby the body attacks itself. Autoimmune diseases include type 1 diabetes, arthritis, lupus, and sclerosis.

Various studies have been conducted on the effect of omega-3 on inflammation. The studies established that omega-3 supplementation increased anti-inflammatory markers (21)(22).

According to these studies, the omega-3 present on the cell membrane of cells is involved in signaling and gene expression. It helps regulate their function to minimize inflammation.

However, note that there is no direct evidence linking the anti-inflammatory property of omega-3 with the treatment of inflammatory diseases (23).

4. Improve mental health

Omega-3 is believed to improve the symptoms of mental illnesses like depression and schizophrenia.

What science says

Various studies and reviews have linked omega-3 with sustained mental wellness. Some studies associate omega-3 deficiency with the development of mental illnesses (24).

Other studies also established that omega-3 supplementation could improve the symptoms of depression and schizophrenia (25).

However, there is still not enough evidence to support the use of omega-3 in the treatment of these mental conditions. There needs to be more research to conclusively establish the efficacy of omega-3 in the treatment of mental health illnesses.

5. Treatment of Skin Disorders

Omega-3 may also protect the skin from skin disorders by protecting it from UV rays.

What science says

Various studies have been conducted on the efficacy of omega-3 in tackling dermatological problems. One such study highlighted the dermatological issues included; acne, skin ulcers, psoriasis, and UV lesions (26) (27).

Another study also shows that omega-3 supplementation can also reduce the risk of non-melanoma skin cancers. It is especially beneficial among populations at a high risk of such cancers (28).

Omega-3 and other long-chain fatty acids like omega 6 are necessary for our skin’s normal function and appearance. For starters, they help regulate the inflammation response of the skin to external stimuli and promote healing without skin damage (29).

The studies also posit that omega-3 enhances the skin’s barrier function. The skin barrier function protects the body from excess loss of water.

6. Protects against eyesight deterioration

Omega-3 proponents believe that it can be used in the treatment of dry eyes.

What science says

There have been a series of studies on the effects of omega-3 on eyesight. The studies were done on both human and animal subjects.

The research studies conducted among human subjects reveal that omega-3 is essential for developing good eyesight during formative years. A series of studies conducted on rats and monkeys showed that omega-3 prevents retinal degeneration and damage (30).

Both studies agree that the DHA type of omega-3 is the intervening factor. It makes up 50% of the brain because of its prominence on brain cells’ cell membranes.

However, research on the use of omega-3 in treating dry eyes remains inconsistent.

Omega-3 Side Effects

Omega-3 is generally safe to take both in dietary form and as a supplement. However, it is not without a few mild side effects. These include:

  • Nausea
  • Heartburn
  • Awful taste
  •  Bad breath
  • Stinky sweat
  • Headaches

Too much omega-3 can also cause bleeding and suppress the immune system because of its anti-clotting and anti-inflammatory properties. Some studies have also linked long-chain fats like omega-3 with increased risk of prostate cancer (31).

Omega-3 Sources

Omega-3 Usage and Dosing Considerations

There is no consensus on the daily recommended dose of omega-3. This is primarily because different omega-3 doses have been proven to tackle various conditions.

For starters, the FDA approved the use of 4g of omega-3 per day in a specific drug to treat high levels of triglycerides. The FDA also recommended 0.8g as the minimum daily dose for foods and supplements labeled as containing omega-3.

For general use, the unofficial recommended dose for adults seems to be 1g per day. The doses also vary for children.

To be on the safe side, ensure you consult your doctor before taking any omega-3 supplements.

Risks and Precautions

If you are on blood-thinning medication, ensure you consult your doctor before taking omega-3. It might compound the blood-thinning effect and cause severe bleeding.

The same goes for any other type of medication to prevent negative medication interaction.

If you have a cardiovascular problem, you should also consult your doctor before taking omega-3 supplements.

If you want to increase omega-3 rich fish in your diet, consider fish with low mercury levels. These include salmon, sardine, cod, and tilapia.

Also, ensure you stick to the recommended dose if taking supplements.


Which is the best type of omega-3?

There are three types of omega-3 fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). Of the three, EPA and DHA are the most important in the body.

They are found in fish oil. ALA is found in seeds and seed oils. It can be converted to the other two forms by the body but at low rates.

Can omega-3 make you fat?

There is evidence, albeit limited, that omega-3 has a modest positive effect on visceral fats. So it can help you shed a pound or two.

Can I take omega-3 with multivitamins?

Yes, both will go a long way in enhancing your health.

When is the best time to take omega-3

Recent research studies show that omega-3 is best taken during meals. They also show that high-fat meals increase the absorption and bioavailability of omega-3.

The Bottom Line

Although our bodies do not make omega-3, it is necessary for most of its functions. Adding omega-3 to your diet will go a long way in improving your health.

However, if an omega-3 rich diet is not a viable option for you, you can opt for omega-3 supplements.

Either way, ensure you take it in moderation.



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