What Does Omega-3 Do for the Body? A Comprehensive Guide to its Benefits

December 12, 2025 •

3 min read

Studies have consistently shown that few nutrients are as thoroughly researched and beneficial as omega-3 fatty acids. Understanding what does omega-3 do for the body is key to leveraging its powerful effects on everything from cardiovascular health to brain function and inflammation management.

Quick Summary

Omega-3 fatty acids are vital components of cell membranes throughout the body, supporting brain development, eye health, and reducing inflammation associated with various chronic diseases.

Key Points

Cellular Structure: Omega-3 fatty acids, especially DHA, are vital components of cell membranes, particularly in the brain and eyes, ensuring proper function.
Heart Protection: They lower triglycerides, blood pressure, and reduce plaque buildup in arteries, contributing significantly to a healthy cardiovascular system.
Brain Health: Crucial for infant brain development and maintaining cognitive function throughout life, with evidence showing potential benefits for memory and mood.
Inflammation Management: With powerful anti-inflammatory properties, omega-3s help reduce chronic inflammation linked to heart disease, arthritis, and other autoimmune conditions.
Dietary Sources: The body cannot produce omega-3s, so they must be obtained from foods like fatty fish (for EPA and DHA) and plant-based sources such as flaxseed, chia seeds, and walnuts (for ALA).
Balancing Intake: An imbalance of too many omega-6s relative to omega-3s is common. Increasing omega-3 intake helps restore a healthy fatty acid balance.

The Three Main Types of Omega-3

Omega-3 fatty acids are a group of essential polyunsaturated fats that the body cannot produce on its own. They must be obtained from the diet. There are three primary types:

Alpha-Linolenic Acid (ALA): Found in plant sources like flaxseed, chia seeds, and walnuts. The body can convert ALA into EPA and DHA, but the conversion rate is low.
Eicosapentaenoic Acid (EPA): Primarily from marine sources, EPA helps produce signaling molecules that reduce inflammation. It also supports mental health.
Docosahexaenoic Acid (DHA): Also mainly from fatty fish and algae, DHA is a key structural component of the brain and eyes, vital for development and function.

How Omega-3 Impacts the Body

Supports Cardiovascular Health

Omega-3s are well-known for their heart benefits. They contribute by lowering triglycerides, potentially reducing blood pressure, slowing plaque buildup in arteries, and decreasing the risk of irregular heartbeats.

Crucial for Brain and Mental Health

DHA is a significant part of the brain, making omega-3s essential for cognitive function and well-being. They are crucial for infant brain development, maintaining cognitive function, potentially benefiting memory and learning, and may help improve symptoms of depression and anxiety. Some research also suggests a potential role in supporting individuals with ADHD.

Fights Inflammation and Autoimmune Disease

Omega-3 fatty acids have strong anti-inflammatory effects by inhibiting inflammatory molecules. This can help manage chronic inflammation associated with conditions like rheumatoid arthritis, Crohn's disease, and psoriasis.

Boosts Eye and Skin Health

DHA is a key component of the retina, and adequate intake may lower the risk of macular degeneration. Omega-3s also benefit skin health by maintaining hydration, protecting against aging, and reducing acne and inflammation.

Omega-3 vs. Omega-6: Striking the Right Balance

Both omega-3 and omega-6 are essential fats, but they have different roles in inflammation. Omega-3s are anti-inflammatory, while omega-6s are pro-inflammatory. A typical modern diet often has an unhealthy imbalance with too many omega-6s, contributing to chronic inflammation.


Feature	Omega-3 Fatty Acids	Omega-6 Fatty Acids
Inflammatory Response	Primarily anti-inflammatory	Primarily pro-inflammatory
Main Function	Cell structure, brain function, heart health	Energy provision
Key Types	ALA, EPA, DHA	Linoleic Acid (LA), Arachidonic Acid (AA)
Primary Sources	Oily fish, flaxseed, chia seeds, walnuts	Vegetable oils (soybean, corn), seeds, nuts
Dietary Challenge	Most people don't consume enough	Abundant in most diets, often in excess

Balancing intake involves increasing sources rich in omega-3s, especially from fish, and reducing consumption of foods high in omega-6 vegetable oils.

Dietary Sources of Omega-3

Meeting omega-3 needs can be achieved through various foods.

Animal-Based Sources (EPA & DHA)

Fatty Fish: Excellent sources include salmon, mackerel, herring, sardines, and anchovies.
Fish Oil and Cod Liver Oil: Concentrated forms often used as supplements.
Oysters: Provide ALA, EPA, and DHA.

Plant-Based Sources (ALA)

Flaxseeds and Flaxseed Oil: Among the richest sources of ALA.
Chia Seeds: Nutrient-dense and high in ALA.
Walnuts: Contain significant ALA.
Soybeans and Edamame: Good sources of ALA and protein.
Algae Oil: A vegan source offering preformed DHA and EPA.

Conclusion

Omega-3 fatty acids are essential nutrients vital for various bodily functions. They support cardiovascular health, brain development and function, manage inflammation, and benefit eye and skin health. While supplements are available, incorporating omega-3-rich foods like fatty fish, nuts, and seeds into your diet is recommended to ensure adequate intake and a healthy balance with omega-6 fatty acids. For general information on omega-3 fatty acids, you can refer to the Omega-3 Fatty Acids - NIH fact sheet.

Frequently Asked Questions

The three main types are Alpha-Linolenic Acid (ALA), found in plants; Eicosapentaenoic Acid (EPA), found in fatty fish; and Docosahexaenoic Acid (DHA), also found in fatty fish and algae.

Incorporating omega-3-rich foods into your diet is a good approach. Sources include fatty fish like salmon and mackerel, as well as plant-based options like flaxseed, chia seeds, and walnuts.

Potential signs can include dry skin, hair, and eyes, joint discomfort, mood fluctuations, fatigue, and issues with focus or memory.

Food sources like fatty fish provide other nutrients and are generally a preferred way to obtain omega-3s for most people. Supplements can be a suitable option for those who do not consume enough fish or have specific dietary needs, ideally discussed with a healthcare provider.

Plant sources provide ALA, but the body's conversion of ALA to the beneficial EPA and DHA is limited. Vegans and vegetarians can include ALA-rich foods and may consider algae oil supplements, which provide preformed DHA and EPA.

Some research suggests that omega-3 fatty acids, particularly EPA, may play a role in supporting mental well-being and could help reduce symptoms of depression and anxiety. They are sometimes used as a complementary approach.

Omega-3s have anti-inflammatory effects by helping to regulate inflammatory pathways in the body. Maintaining an appropriate ratio of omega-3 to omega-6 fatty acids is considered important for managing the body's inflammatory response.