Why Is Omega-3 Good for Skin? A Closer Look at the Science Behind Skin Structure and Function

It’s easy to focus on the face in conversations about skincare, but skin is everywhere — a dynamic, living organ that protects, senses, regulates, and renews itself continuously. And like every organ in the body, it needs the right building blocks to function well.

One of those key building blocks are lipids — specifically, omega-3 fatty acids. Best known for their role in brain and heart health, omega-3s also play an essential, though less talked-about, role in skin structure and function.

In this article, we’ll take a closer look at what omega-3s do in the skin — beyond the beauty buzzwords — and how they may contribute to its health from the inside out.

Think about a time when you’ve eaten something salty—like crisps or a takeaway. That extra salt increases the concentration of sodium in your blood. In response, your body pulls water out of your cells and tissues into the bloodstream to help dilute the salt and restore balance.

As water leaves the cells, they shrink slightly. This is one of the reasons you might feel thirsty, have a dry mouth, or get a headache after eating salty foods—your cells are dehydrated. Brain cells are especially sensitive to this shift, which is why eating salty foods can sometimes lead to a headache if you don’t drink enough water afterwards.

Omega-3s are a group of essential polyunsaturated fats (PUFAs), meaning the body cannot produce them on its own — they must come from the diet. The three main types are:

EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) – primarily found in oily fish and marine algae.

ALA (alpha-linolenic acid) – found in plant-based foods like flaxseeds, chia seeds and walnuts.

The body converts only a small percentage of ALA into EPA and DHA, which are the forms most directly used in skin cell function and for this reason, dietary sources of EPA and DHA are particularly important.

The outermost layer of skin, known as the stratum corneum, plays a critical role in keeping moisture in and irritants out. This layer is often described as a "brick and mortar" structure — with skin cells (the bricks) surrounded by a lipid matrix (the mortar). This lipid layer is made up of ceramides, cholesterol, and fatty acids, including omega-3s.

Omega-3 fatty acids help support the composition and fluidity of this barrier . A well-balanced lipid matrix helps the skin retain moisture more effectively and reduces water loss through the surface. 

One of the lesser-known roles of omega-3s is their contribution to the skin’s natural ability to hold onto water. While drinking plenty of fluids is important, hydration is also about the skin’s capacity to retain moisture where it’s needed. Omega-3s influence this by maintaining the integrity of the lipid barrier in the stratum corneum, which acts like a seal to reduce moisture escaping from the skin’s surface.

This is particularly relevant in colder months or in environments with dry air, where water loss from the skin can be more pronounced. By supporting the skin’s internal structure, omega-3s help to reinforce its natural hydration mechanisms.

Omega-3s and hyaluronic acid both play unique roles in keeping skin hydrated — but in different ways. Hyaluronic acid helps draw water into the skin, while omega-3s support the barrier that keeps that moisture locked in. Although they work independently, they complement one another in maintaining skin softness, structure, and resilience.

The skin is more than just a passive shield — it’s an active immune organ that responds to environmental stimuli, internal changes, and dietary inputs. Omega-3s particularly EPA and DHA are precursors to specialised pro-resolving mediators (SPMs) called resolvins and protectins, which are involved in supporting the body’s ability to manage and wind down inflammatory responses , including those that can affect the skin. 

When the skin barrier is compromised, it can become more reactive — feeling itchy, flushed, or overly sensitive to products or temperature changes. This sensitivity is often linked to an imbalance in the lipids that make up the skin’s protective layer.

Omega-3s contribute to skin resilience by influencing the balance of fatty acids in cell membranes and supporting how skin cells respond to external signals. They help reinforce the structure of the skin’s outermost layer. 

Every cell in the body is surrounded by a membrane, and these membranes are partly made up of fats — including omega-3s. In skin cells, these fats help maintain membrane fluidity.

Healthy membranes also support the process of skin turnover — the natural cycle of shedding old skin cells and replacing them with new ones. This process relies on nutrient availability and cellular communication, both of which can be influenced by omega-3 intake.

When it comes to skin, what we see on the surface is often a reflection of complex inner workings. Omega-3 fatty acids are not a quick fix or a cosmetic solution — they’re a foundational nutrient that contributes to how the skin functions at a cellular level.

From supporting the barrier that keeps moisture in, to influencing how skin responds to the world around it, omega-3s are a quiet but essential part of the bigger picture. In the end, nourishing the skin is as much about what’s on the plate as what’s in the mirror.