THP

fatty_acid

Omega-3

Moderate Evidence
Last reviewed July 2026

Essential fatty acids most people are under-consuming. Important for heart, brain, joints and skin.

Overview

Omega-3 fatty acids are essential fats — the body cannot synthesise them and they must come from diet. The two most clinically important forms are EPA and DHA, found primarily in oily fish and algae. DHA is a structural component of the brain and retina. EPA plays a key role in regulating inflammation. Most UK adults eat far less oily fish than the NHS recommends (two portions per week, one oily), making omega-3 supplementation one of the most broadly justified interventions.

Evidence rating

Moderate Evidence

Strong evidence for triglyceride reduction at prescription doses. Moderate evidence for joint inflammation, depression support and skin barrier function. DHA is critical for fetal brain development. Evidence for cognitive decline prevention in healthy adults is mixed.

Common uses

  • Strong Evidence
    Reducing blood triglycerides and supporting cardiovascular health
  • Moderate Evidence
    Reducing joint inflammation and stiffness
  • Moderate Evidence
    Supporting brain health and mood
  • Moderate Evidence
    Skin hydration and barrier function
  • Strong Evidence
    Supporting fetal brain development in pregnancy (DHA)

Safety & cautions

Worth checking with a pharmacist if you take medication.

Common forms

Fish Oil (EPA+DHA)Best form

The standard form. Look for high combined EPA+DHA content per capsule (aim for 1,000mg+ combined).

Algae Oil (vegan omega-3)

Derived from algae. Provides both EPA and DHA. More sustainable and suitable for vegans.

Cod Liver Oil

Contains EPA+DHA plus vitamins A and D. Do not combine with additional vitamin A.

Food sources

  • Salmon (fresh)Approx. 2.2g EPA+DHA per 100g
  • MackerelApprox. 2.6g EPA+DHA per 100g
  • Sardines (tinned)Approx. 1.8g EPA+DHA per 100g
  • HerringApprox. 2.0g EPA+DHA per 100g