Omega-3s, Where Will You Get Yours?

Plant vs fish vs algae, what kind of omega-3s actually matter? And do your genes weigh in?

Omega-3s are one of those nutrients that come with a health halo. They’re everywhere, from skin creams to prenatal supplements to the corner of every wellness infographic telling you to “eat more salmon".

But when you start unpacking the types (ALA? DHA? EPA?), the sources (chia? fish? algae?), and the genetic variables (looking at you, FADS1/FADS2), things can get a little confusing.

So let’s break it down: What kind of omega-3s actually matter?

How do plant, fish, and algae sources compare?

And do your genes influence how well your body uses them?

The Omega-3 Family: What They Are and Why They Matter

Omega-3s are a type of polyunsaturated fat that play a critical role in cellular health.

They’re woven into the very structure of your cells, especially in your brain, eyes, heart, and reproductive tissues. They're also key regulators of inflammation, mood, and hormone signalling.

There are three main omega-3s involved in human health:

• ALA (alpha-linolenic acid) – Found in flaxseeds, chia seeds, hemp seeds, and walnuts

• EPA (eicosapentaenoic acid) – Found in cold-water fatty fish and algae

• DHA (docosahexaenoic acid) – Also found in fish and algae; crucial for brain, retina, and cell membrane structure

ALA is the plant-based version. Your body can convert it into EPA and DHA, but not very efficiently. And for some people, not much at all.

This matters because EPA and DHA are the biologically active forms that actually get incorporated into your tissues and used for anti-inflammatory signalling, brain health, and hormone modulation.

Plant-Based Omega-3s: Still Valuable, But With Limits

Let’s start with the good: Plant-based omega-3s, like those in flax, chia, and hemp, are still worth including.

They’re anti-inflammatory, fibre-rich, and come with beneficial lignans that support hormone detox and gut health. They’re especially helpful if you’re plant-based or working on digestive diversity.

But here’s the limitation: ALA (the plant form) has to be converted by your body into EPA and DHA, and this conversion is extremely limited.

On average, research shows:

• Only about 5–10% of ALA gets converted into EPA

• Less than 2–5% gets converted into DHA

And that’s in people with efficient metabolic pathways.

If your body isn’t good at making that conversion, even a flax-packed smoothie bowl won’t give you what your nervous system or inflammation pathways actually need.

The Genetic Link: FADS1 & FADS2

Two key genes, FADS1 and FADS2, control the enzymes responsible for converting ALA into EPA and DHA. Think of them like your omega-3 conversion crew.

But not everyone has the same version of those genes.

Some people carry genetic variations (SNPs) that reduce enzyme efficiency, meaning their bodies produce less EPA and DHA even when they’re consuming ALA-rich foods.

This isn’t uncommon, reduced-function FADS1/FADS2 variants show up in a significant portion of the population and can influence everything from brain function to inflammation regulation to hormonal balance.

If you’re one of them, you may:

• Struggle with inflammation despite a healthy diet

• Feel foggy, tired, or moody even with plant-based omega intake

• Notice skin, joint, or hormonal changes during stress, perimenopause, or after illness

• Show lower omega-3 levels on a blood test or Omega-3 Index

This is where a simple DNA insight can help explain why the food you’re eating might not be working the way it should.

Fish-Based Omega-3s: Direct and Bioavailable

These SMASH fish provide pre-formed EPA and DHA, meaning no conversion needed. Your body can absorb and use these immediately, supporting cell membranes, hormone receptors, and anti-inflammatory pathways throughout your body. These include:

• Sardines

• Mackerel

• Anchovies

• Salmon

• Herring

And Here’s Where I’m Supposed to Say: “Just Eat Fish Three Times a Week”

That’s the line, right?

This is where the omega-3 conversation often gets flattened, into a tidy public health slogan: “Eat oily fish two to three times a week".

And look, on paper, it tracks. Fish (especially oily ones like salmon, sardines, and mackerel) are rich in EPA and DHA, the long-chain omega-3s your body can’t make on its own. These are essential for brain health, cell membranes, inflammation balance, and more.

So yes, as a whole food? They’re one of the most bioavailable sources we’ve got.

But in real life?

The Sustainability Problem

Let’s zoom out for a minute.

If everyone followed that advice and started eating wild fish three times a week, we’d run into serious ecological issues, fast. Wild fish stocks are already under stress.

And farmed fish? Often marketed as the “sustainable” alternative. That story’s got some questionable chapters of its own. Especially the controversy surrounding Australian salmon farming.

So yes, the SMASH fish (sardines, mackerel, anchovies, salmon, herring) look great on a graphic. But are you really going to eat these fish, three times a week, every week, always?

Maybe you will. Maybe you live somewhere coastal, have access to a great fishmonger, and genuinely love preparing seafood.

Or maybe… you don’t.

But Here’s the Non-Negotiable

Your body, and especially your brain, needs omega-3s. Not in theory. In practice.

They’re essential. As in: your body can’t make them.

Not optional. Not hype. They have to come from somewhere. From your environment. From food. From a source that makes sense in your life.

So yes, I cook fish. I encourage whole food sources whenever possible. But when we’re talking about meeting long-chain omega-3 needs consistently, sustainably, and affordably, we often need more than just a salmon plan.

Algae Oil: The Best of Both Worlds for Some

If SMASH fish aren’t on your plate three times every week, because of dietary choice, ethical reasons, or sustainability concerns, algae oil is the next best thing.

Because here’s the part most of us forget:

Fish don’t make omega-3s. They get them from algae.

That’s the original source of DHA and EPA in the marine food chain. Fish just concentrate it. Which means we can skip the middle swimmer and go straight to the algae, without the mercury, microplastics, or overfishing.

Algae oil provides preformed DHA (and often EPA), it can be grown in controlled environments. It’s vegan, sustainable. It doesn’t require fishing nets or ocean stress. It’s shelf-stable. And it doesn’t taste like low tide.

Is it the same as a sardine? No. But when you’re looking at your week, your plate, your needs, algae oil offers a realistic way to consistently support your brain and biology.

DHA + EPA Source Comparison Table

Source	DHA + EPA Content	Bio-availability	Sustainability	Consider
Wild-caught salmon	High	Excellent	Moderate–Low (depends on fishery)	Whole food, but not accessible or affordable for all. Overfishing is a concern.
Sardines, anchovies, mackerel (SMASH fish)	High	Excellent	High (small fish, short life cycle)	Great option if tolerated; may still contain heavy metals.
Farmed salmon	Moderate–High (varies by feed)	Good	Low	Farming practices vary. Some linked to environmental damage + poor feed quality.
Algae oil	Moderate–High (DHA-rich, some EPA blends)	Excellent	Very High	Vegan, sustainable, clean. Great for daily consistency + brain support.
Cod liver oil	Moderate	Good	Moderate	Whole food, also contains vitamin A + D. Risk of oxidation if not high quality.
Krill oil	Moderate	High (phospholipid-bound)	Controversial	Small-scale sustainable claims exist, but ecological impact on marine food chain still debated.
Chia/flax/hemp seeds	Only ALA (no DHA/EPA)	Poor (conversion <5%)	High	ALA must be converted to EPA/DHA—inefficient in humans. Still valuable, but not sufficient alone.

The Bottom Line

Omega-3s aren’t optional.

They shape everything from your memory to your mood to how your cells talk to each other. And your body can’t make them. Which means your environment has to provide them. Your plate. Your pantry. Your plan.

Maybe that’s local fish, cooked with intention. Maybe it’s algae oil, backed by good sourcing and third-party testing. Either way, the goal isn’t to follow a slogan. It’s to meet a need.

Because this isn’t about whether you eat salmon. It’s about whether your brain is getting what it actually needs to function.

You don’t need a fish-forward lifestyle. But you do need omega-3s.

And how you get them and how your body uses them matters. There’s no one right answer, only the right fit for your biology, your values, and your current season of life.

Want to see where the science comes from? For the extra curious, the references are here.