The Ultimate Guide to Choosing a High-Quality Fish Oil: What You Need to Know

Part 1: Purity, Processing, and the Power of Triglycerides

Why Fish Oil Matters

Omega-3s are among the most multifunctional nutrients we know — essential for everything from brain development to heart health — yet most people don’t get nearly enough in their daily diet.

Backed by decades of research, fish oil is associated with a wide range of potential health benefits:

• Heart health: Omega-3s help lower triglycerides, reduce blood pressure, and support arterial function.
  [Clinical trial]
  
• Brain function: DHA is a key structural fat in the brain and retina — vital for cognitive performance and mental clarity.
  [Study link]
  
• Inflammation & joints: EPA may play a key role in regulating inflammation, with implications for arthritis, autoimmune conditions (PubMed), and post-exercise recovery (PMC). More research is needed, particularly around athletic use.
  
• Mood support: EPA-rich fish oils have shown promise in reducing symptoms of depression and anxiety in emerging studies — though more robust research is needed.
  PMC
  
• Other benefits: Eye health, pregnancy support, skin health — the list continues to grow as research evolves.
  

Clearly, fish oil matters. But not all fish oils are created equal — and many products on the market fall short in purity, potency, or absorption.

Let’s fix that.

The Hidden Differences That Make or Break Fish Oil Quality

Scroll through any high street supplement aisle or an Amazon results page and you’ll find dozens of fish oil products — all boasting high omega-3 numbers and glossy marketing.

But the real differences lie in the details most labels don’t mention:

• How the oil was extracted
  
• What molecular form the omega-3s are in
  
• The type and source of fish used
  
• Whether it’s wild or farmed
  
• Whether it includes naturally occurring nutrients like vitamin D or astaxanthin
  

This guide explains all of that — so you can shop with confidence and see why One Life Foods Wild Alaskan Sockeye Salmon Oil stands apart.

1. Processing: Where Most Fish Oils Go Wrong

Processing might sound boring — but it’s the foundation of quality. Poor processing can destroy the very nutrients you're taking fish oil for.

 Low-Grade Processing Often Involves:

• High heat – which damages delicate omega-3s.
  
• Chemical solvents – like hexane, which can leave behind residues.
  
• Bleaching & deodorising – used to mask rancidity.
  
• Poor storage – exposure to light or oxygen leads to oxidation (rancid oil).
  

Result? A less effective, unstable product with degraded nutrients and potential contaminants.

High-Quality Processing Should Include:

• Cold extraction – protects omega-3s from heat damage.
  
• Nitrogen blanketing – prevents oxidation during processing and bottling.
  
• Minimal handling – retains the oil’s natural structure and nutrients.
  
• Rigorous testing – including oxidation levels (look for TOTOX < 26), heavy metals, and PCBs.
  

Bottom line: Poorly processed oils may be oxidised or contain contaminants, potentially undermining the very health benefits they promise.

2. Triglyceride vs. Ethyl Ester: Why Form Matters More Than Dose

Most fish oil labels list omega-3 amounts in milligrams — but the molecular form (how it's structured) is what really affects absorption.

What's the Difference?

Natural Triglyceride (TG) Form

• Found naturally in fish
  
• Better absorbed by the body (bioavailable)
  
• More stable and usually better tolerated
  

 Ethyl Ester (EE) Form

• Created through chemical processing with ethanol
  
• Cheaper to produce
  
• More prone to oxidation and rancidity
• Less bioavailable — studies show ethyl ester forms may be absorbed 20–70% less efficiently than triglyceride or monoglyceride forms.

It has been proposed triglyceride-form fish oil may be absorbed 20–70% more efficiently than ethyl ester forms, depending on individual factors and formulation. Meaning two products with the same omega-3 content may deliver vastly different benefits.

At One Life Foods, we use only 100% natural triglyceride-form oil — for better absorption, stability, and digestibility.

3. Natural Nutrients vs. Synthetic Add-Ins

Many fish oils lose their natural co-nutrients during harsh processing. Manufacturers then "enrich" them by adding synthetic vitamins — but this isn’t the same.

Why Natural Nutrients Matter:

• Vitamin D – occurs naturally in wild salmon oil; supports mood, bones, and immunity.
  
• Vitamin A – present in small, balanced amounts. (Note: cod liver oil can contain excessive vitamin A — High intake over time can pose a toxicity risk, especially during pregnancy).
  
• Astaxanthin – a potent antioxidant that gives wild salmon its red colour and helps protect omega-3s from oxidation inside your body.
  

 One Life’s Wild Alaskan Sockeye Salmon Oil includes:

• 690 mg total omega-3s, including naturally occurring EPA and DHA. per softgel (batch-dependent)
  
• Natural vitamin D: 6 μg (120% of DRI)
  
• Astaxanthin: ~16.5 μg — plus natural tocopherols for added stability
  

4. Fish Sources: Not All Fish Are Created Equal

Where your fish oil comes from makes a big difference — not just in terms of purity, but sustainability and ethics too.

Common Sources:

• Anchovies / sardines / mackerel – small, oily fish with lower mercury risk
  
• Tuna – often high in mercury; avoid in large, long-term doses
  
• Farmed salmon – cheaper, but often lower in omega-3s and higher in omega-6s
  

Our Choice: Wild-Caught Alaskan Sockeye Salmon

• Naturally rich in astaxanthin
  
• MSC-certified for sustainability
  
• Uses the head oil — a high-quality, low-waste approach
  
• Lower in EPA/DHA than concentrates, but more bioavailable and naturally balanced. While some concentrated oils offer higher EPA/DHA per dose, whole-food forms like salmon oil deliver omega-3s alongside natural co-factors that may support better utilisation.
  
  It’s about quality, not quantity — delivering omega-3s the way nature intended.

5. EPA vs DHA: Which Do You Need?

Both EPA and DHA are important, but their roles differ:

• EPA – inflammation support, mood, cardiovascular health
  
• DHA – brain development, vision, pregnancy support
  

Your needs may vary:

• Dealing with low mood or inflammation? Aim for more EPA.
  
• Supporting pregnancy or cognition? Prioritise DHA.
  

However, absorption and quality matter more than raw numbers. A well-processed TG-form oil can outperform a high-dose EE product.

What to Look For in a Fish Oil Supplement

Feature	What to Look For
Form	Natural triglyceride (not ethyl ester)
Processing	Cold-extracted, nitrogen-protected
Sourcing	Wild-caught, MSC-certified
Fish Type	Small oily fish or wild salmon
Nutrient Content	Natural vitamin D, astaxanthin
Purity Testing	3rd-party tested, low TOTOX
Transparency	Clear sourcing, method, and lab reports

In Summary

Fish oil can be transformational for your health — but only when it’s high-quality, well-sourced, and properly processed.

One Life Foods Wild Alaskan Sockeye Salmon Oil ticks every box:

• Cold-extracted & minimally processed
  
• 100% natural triglyceride form
  
• Sustainably sourced from MSC-certified fisheries
  
• Naturally rich in vitamin D and astaxanthin
  
• Sourced from a pristine marine ecosystem
  

It’s not just fish oil — it’s intelligent nutrition for a cleaner, more conscious approach to supplementation.

Coming Up Next:

Part 2: The Truth About Fish Oil Sourcing and Sustainability
We’ll explore what “Nordic-sourced” really means, uncover industry shortcuts, and show why wild Alaskan sockeye is one of the most ethical, sustainable choices on the planet.