If there’s one nutrient that pescetarianism is particularly celebrated for, it’s omega-3 fatty acids. These essential fats — ‘essential’ meaning your body can’t produce them and you must get them from food — are linked to an impressive range of health benefits, from cardiovascular protection to brain function to reduced inflammation.
The Three Types of Omega-3
ALA — Alpha-linolenic acid
Found in plant foods like flaxseeds, chia seeds, hemp seeds, and walnuts. ALA is the most common omega-3 in Western diets, but the body can only convert a small percentage of it into the more active forms (EPA and DHA).
EPA — Eicosapentaenoic acid
Found primarily in oily fish and seafood. EPA is strongly linked to reducing inflammation and supporting cardiovascular health. This is one of the main reasons oily fish consumption is so consistently associated with better heart outcomes in research.
DHA — Docosahexaenoic acid
Also found primarily in oily fish and seafood. DHA is the primary structural fat in the brain and retina. It’s critical for brain development, cognitive function, and eye health throughout life.
Top Fish and Seafood Sources of Omega-3
Ranked roughly by omega-3 content per 100g serving:
- Mackerel — one of the richest sources available, around 5g of omega-3 per 100g
- Salmon (wild) — around 2.5-3.5g per 100g
- Herring — similar to mackerel, often overlooked but excellent
- Sardines — around 1.5-2.5g per 100g, fresh or tinned
- Anchovies — small but mighty, high in omega-3 and great flavour
- Trout — a freshwater option with solid omega-3 content
- Tuna — lower than oily fish but still a useful source
- Mussels and oysters — modest omega-3 content but great overall nutritional profile
Plant-Based Omega-3 Sources to Include
- Flaxseeds and flaxseed oil — one of the richest plant sources
- Chia seeds — easy to add to yoghurt, smoothies, or overnight oats
- Hemp seeds — great on salads and bowls
- Walnuts — the best nut source of ALA
- Edamame — modest but useful contribution
How Much Do You Need?
The NHS recommends at least two portions of fish per week, one of which should be oily. Most health bodies suggest aiming for around 250-500mg of EPA and DHA combined per day for general health maintenance. A single portion of mackerel or salmon comfortably exceeds this.
Do You Need an Omega-3 Supplement?
If you’re eating oily fish two or more times a week, probably not. If your fish intake is low, a supplement might be worth considering. Look for fish oil capsules with a combined EPA and DHA content of at least 250mg per dose. Algae-based omega-3 supplements are also available — derived from the algae that fish eat, they’re a good option if you want to reduce your reliance on fish.
Practical Ways to Boost Your Omega-3 Intake
- Swap white fish for oily fish at least twice a week — salmon, mackerel, or sardines
- Keep tinned mackerel and sardines in the cupboard for quick high omega-3 meals
- Add chia seeds or ground flaxseed to your morning yoghurt or porridge
- Snack on walnuts rather than other nuts
- Try herring or kippers — underrated, very affordable, extremely high in omega-3
Sources & Further Reading
- NHS — Omega-3 — https://www.nhs.uk/conditions/vitamins-and-minerals/others/#omega-3
- British Heart Foundation — Omega-3 and fish oils — https://www.bhf.org.uk/informationsupport/heart-matters-magazine/nutrition/fish-and-omega-3
- American Heart Association — Fish and omega-3 fatty acids — https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/fish-and-omega-3-fatty-acids
- Harvard Health — No need to avoid healthy omega-3 fats — https://www.health.harvard.edu/heart-health/no-need-to-avoid-healthy-omega-3-fats
- NIH Office of Dietary Supplements — Omega-3 Fatty Acids — https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/