Docosahexaenoic Acid (DHA)

🔗 Omega-3 Family & Related Pages

DHA is one of the three key Omega-3 fatty acids. Explore each form:

Compare other fat families: Omega-6 • Omega-9 (incl. Oleic acid).

🧬 Molecular Identity

• Chemical formula: C₂₂H₃₂O₂ • 22:6 (n-3)
• Source: Primarily marine/algal oils (fish, krill, microalgae)
• Solubility: Fat-soluble; absorbed with dietary lipids
• Structure: Very long-chain PUFA with six cis double bonds

🌿 Plain-Language Summary

DHA is a structural omega-3 found in cell membranes throughout the body, especially in the brain and retina. It’s obtained from marine or algal sources and is formed in small amounts from dietary ALA, though conversion is limited. Many people use direct dietary sources to reach typical long-chain omega-3 intakes.

⚡ Functions

• Major structural component of neuronal and retinal membranes
• Supports membrane fluidity and receptor signalling
• Along with EPA, contributes to specialised pro-resolving mediators (SPMs) pathways

🍽️ Absorption & Bioavailability

Direct marine or algal DHA can help when ALA→DHA conversion is insufficient.

🇦🇺 Australian Guidance (NHMRC)

• Suggested Dietary Target (long-chain n-3, EPA+DHA): ~610 mg/day (men) • ~430 mg/day (women)
• ALA Adequate Intake (AI): 1.3 g/day (men) • 0.8 g/day (women)
• See NHMRC Nutrient Reference Values for details

🥗 Food Sources

• Marine: Salmon, sardines, mackerel, anchovies, herring, tuna (varies by species)
• Plant-based: Algal oil (direct DHA/EPA source)

Wild fish often contain higher EPA/DHA than farmed varieties. For plant-based diets, use algal DHA.

🧪 Testing & Monitoring

• Omega-3 Index (% EPA + DHA in RBC membranes) — not routinely required
• Fatty acid profiles available via specialised labs (context-dependent)
• Discuss personal needs with your healthcare provider

🔗 Interactions

• High-dose fish oils may interact with anticoagulant/antiplatelet regimens — seek professional advice
• Shares enzymes and pathways with omega-6 family (desaturases/elongases)
• Supportive cofactors: zinc, magnesium, vitamin B6

See related: EPA • ALA • Compare families: Omega-6 • Omega-9

📊 Evidence Snapshot

• 🔬✅ Well-established: Structural role in retina/brain; contribution to membrane fluidity
• 🧪⚖️ Promising/mixed: Outcomes vary by dose, baseline diet, and population
• ⚠️❌ Unproven/hype: Cure-all or rapid performance claims

Explore the full Omega-3 Overview and related pages: EPA • ALA.