Understanding What Lipids Are Considered Essential Nutrients

January 1, 2026 •

3 min read

According to the Linus Pauling Institute, only two fatty acids, alpha-linolenic acid (ALA) and linoleic acid (LA), are known to be essential nutrients for humans, as the body cannot synthesize them from scratch. These specific lipids must therefore be obtained through diet to support numerous vital bodily functions.

Quick Summary

This article defines the specific fatty acids the human body cannot produce, detailing the roles of omega-3 and omega-6 families, their dietary sources, and importance for overall health.

Key Points

Two Primary Essential Fatty Acids: The human body cannot synthesize Alpha-linolenic acid (ALA) and Linoleic acid (LA), making them essential dietary lipids.
Omega-3 and Omega-6 Roles: These two families of lipids have distinct, and sometimes opposing, roles in the body's inflammatory and signaling pathways, necessitating a proper dietary balance.
Inefficient Conversion: The body's ability to convert plant-based ALA into the more active forms, EPA and DHA, is very limited, highlighting the importance of consuming marine sources.
Vital for Cell Function: Essential fatty acids are crucial structural components of cell membranes, impacting their fluidity and enabling proper communication and function, especially in the brain and retina.
Signs of Deficiency: Inadequate intake can manifest as physical symptoms such as dry, scaly skin, hair loss, and neurological issues like poor concentration and mood swings.

Essential Fatty Acids: The Foundational Essential Lipids

While the term "lipids" includes a wide range of compounds, only certain polyunsaturated fatty acids (PUFAs) are considered truly essential because the human body cannot synthesize them due to lacking necessary enzymes. These essential lipids must be consumed through diet. The two primary essential fatty acids are alpha-linolenic acid (ALA), an omega-3 fatty acid, and linoleic acid (LA), an omega-6 fatty acid.

The Critical Role of the Omega-3 Family

Alpha-linolenic acid (ALA) is the parent omega-3 fatty acid. The body can convert ALA into longer-chain omega-3s like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but this process is often inefficient in humans. Direct dietary intake of EPA and DHA is therefore highly recommended. Omega-3 fatty acids are vital for many physiological processes.

Functions of Omega-3s

Cellular Structure: Key components of cell membranes, particularly in the retina and brain.
Anti-inflammatory Effects: Help manage chronic inflammation.
Cardiovascular Health: Support heart health by lowering triglycerides and blood pressure.
Mental Well-being: Linked to a reduced risk of depression.

Dietary Sources of Omega-3s

ALA: Flaxseeds, chia seeds, walnuts, and canola oil.
EPA and DHA: Fatty fish like salmon and mackerel, and algal oil.

The Indispensable Omega-6 Family

Linoleic acid (LA) is the essential parent omega-6 fatty acid, which the body converts to other omega-6s, including arachidonic acid (AA). Omega-6 fatty acids are crucial for the immune response, blood clotting, and healing. However, Western diets often have an imbalance with too many omega-6s compared to omega-3s.

Functions of Omega-6s

Cell Membrane Integrity: Important for cell structure.
Pro-inflammatory Signaling: Contribute to inflammation, necessary for fighting infection.
Skin Barrier Function: Linoleic acid is essential for skin health.

Dietary Sources of Omega-6s

LA: Sunflower oil, corn oil, safflower oil, soybeans, and nuts.

The Critical Omega-6 to Omega-3 Balance

Maintaining a proper balance between omega-6 and omega-3 fatty acids is crucial, as they compete for the same enzymes. An imbalanced ratio, common in Western diets (often 15:1 to 20:1 instead of the healthier 4:1 or lower), can lead to excessive pro-inflammatory signaling and increased risk of chronic diseases like heart disease. Improving this balance involves reducing foods high in omega-6s and increasing omega-3 intake.

Comparison of Essential Fatty Acids


Feature	Omega-3 (ALA)	Omega-6 (LA)
Classification	Polyunsaturated fatty acid (PUFA)	Polyunsaturated fatty acid (PUFA)
Primary Function	Anti-inflammatory, neurological health, vision	Pro-inflammatory response, skin integrity, hormone signaling
Metabolites	EPA, DHA, resolvins, protectins	Arachidonic acid, pro-inflammatory eicosanoids
Common Sources	Flaxseed, chia seeds, walnuts, fatty fish	Vegetable oils (sunflower, corn), nuts, seeds
Effect on Inflammation	Generally anti-inflammatory	Generally pro-inflammatory

Consequences of Essential Fatty Acid Deficiency

Essential fatty acid deficiency is rare but can cause several health issues, often starting with skin problems. Symptoms may include:

Dry, scaly skin
Increased thirst
Dry hair and hair loss
Slow wound healing
Poor growth in children
Vision problems
Neurological and mood issues
Joint pain

A blood test showing an elevated ratio of mead acid to arachidonic acid can indicate a deficiency.

Conclusion: Prioritizing Essential Lipids for Lifelong Health

Alpha-linolenic acid (ALA) and linoleic acid (LA) are the essential lipids the body needs but cannot produce. They are crucial for cell structure, nervous system function, and regulating inflammation. While supplements can help, especially for EPA and DHA, getting these nutrients from whole foods is best. Balancing omega-3 and omega-6 intake supports overall health and helps manage inflammation. For more information, consult resources like the Linus Pauling Institute.

## Sources of Essential Lipids

Omega-3 (ALA): Flaxseed, chia seeds, walnuts, and canola oil
Omega-3 (EPA/DHA): Fatty fish (salmon, mackerel, sardines), fish oil, and algal oil
Omega-6 (LA): Sunflower oil, corn oil, soybeans, nuts, and seeds
Omega-6 (GLA): Evening primrose oil, borage oil, and blackcurrant seed oil

A balanced diet with these essential lipids is fundamental for maintaining health.

Frequently Asked Questions

The main difference is that essential fatty acids, such as omega-3s and omega-6s, cannot be produced by the human body and must be obtained from the diet. The body can produce non-essential fatty acids on its own.

A balanced ratio is important because both types of fatty acids are metabolized using the same enzymes, and they produce different eicosanoids that regulate inflammation. An imbalanced ratio, common in Western diets, can lead to chronic inflammation.

EPA and DHA are not considered essential in the same way as ALA and LA. While crucial for health, the body can produce small amounts of EPA and DHA from ALA, though this conversion is inefficient. Therefore, they are often called conditionally essential or simply important to consume directly.

Symptoms can include dry, scaly skin, hair loss, vision problems, and cognitive issues. A diagnostic blood test can measure the ratio of specific fatty acids to determine if a deficiency exists.

For ALA, excellent plant-based sources include flaxseeds, chia seeds, and walnuts. For the more active EPA and DHA, consume fatty fish like salmon and mackerel, or consider algal oil for a vegan option.

Linoleic acid (LA) is vital for maintaining the integrity of cell membranes and for the production of signaling molecules that are part of the body's pro-inflammatory immune response and blood clotting processes.

While omega-6s are essential, a disproportionately high intake compared to omega-3s can shift the body towards a pro-inflammatory state, potentially increasing the risk of chronic inflammatory diseases.