Fatty Acid

DHA

Docosahexaenoic acid (22:6 n-3)

Evidence TierAWADA NOT PROHIBITED

tuneTypical Dose

500-1,000 mg per day

watchEffect Window

3-6 months for measurable cognitive or structural effects. Triglyceride reduction within 4-8 weeks.

check_circleCompliance

WADA NOT PROHIBITED

Overview

Clinical Summary

DHA is an omega-3 fatty acid concentrated in the brain and retina. It is used to support neurodevelopment and visual function and to contribute to triglyceride lowering in low intake diets.

DHA supports fetal and infant brain and visual development, with strongest relevance during pregnancy and early life. In adults, it lowers triglycerides and may reduce inflammation biomarkers, with mixed results for cognition. Minority evidence suggests mood and sleep effects in some groups. Benefits are most likely when baseline omega-3 intake is low and when doses are sufficient.

Primary structural omega-3 in brain tissue (~40% of brain PUFA). Incorporates into neuronal membranes, modulating fluidity, receptor function, and neurotransmitter release. Produces anti-inflammatory lipid mediators (protectins, resolvins).

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Essential for fetal brain and retinal development during pregnancy (Cochrane-level evidence). Supports cognitive maintenance in older adults with age-related decline (MIDAS trial).

Secondary Outcomes

  • Reduces serum triglycerides. May modestly improve memory in mild cognitive impairment. Structural component of neuronal membranes supporting synaptic plasticity.

Safety

Contraindications and Interactions

Contraindications

  • Fish or shellfish allergy (use algal DHA)
  • Active bleeding disorders

Side effects

  • Fishy burps and aftertaste
  • Mild GI upset (nausea, bloating)
  • Fishy body odor at high doses

Interactions

  • Anticoagulants and antiplatelet agents (additive bleeding risk at high doses)
  • Antihypertensives (mild additive BP lowering)
  • Orlistat (may reduce absorption)

Avoid if

  • Scheduled surgery within 2 weeks
  • Active internal bleeding

Evidence

Study-level References

dha-SRC-001RCT (MIDAS trial)
Sourceopen_in_new

Yurko-Mauro K, et al. "Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline." Alzheimers Dement. 2010.

Population: Healthy older adults with age-related cognitive decline

Dose protocol: Source-listed

Key findings: 24-week supplementation with 900 mg/d DHA improved learning and memory function in age-related cognitive decline and is a beneficial, well-tolerated intervention.

Paper content

24-week supplementation with 900 mg/d DHA improved learning and memory function in age-related cognitive decline and is a beneficial, well-tolerated intervention.

dha-SRC-002Systematic review and meta-analysis of randomized controlled trials.
Sourceopen_in_new

Tian A, Xu L, Szeto IM, Wang X, Li D. Effects of Different Proportions of DHA and ARA on Cognitive Development in Infants: A Meta-Analysis. Nutrients. 2025;17(6):1091. doi:10.3390/nu17061091. PMID:40292560.

Population: Infants across 9 RCTs (1,039 subjects total).

Dose protocol: Meta-analysis of 9 RCTs (1,039 infants) evaluating DHA/ARA supplementation in infant formula at varying ratios

Key findings: DHA/ARA supplementation had a small positive effect on cognitive development (SMD 0.21, 95% CI 0.03 to 0.38). Optimal benefit at DHA/ARA ratio of 0.5 to 1 with significant MDI and PDI improvements.

Notes: Reinforces the neurodevelopmental evidence for DHA in early life and provides practical guidance on optimal DHA/ARA formulation ratios.

Paper content

This meta-analysis of 9 RCTs (1,039 infants) examined how different DHA-to-ARA ratios in infant formula affect cognitive development. Overall, DHA/ARA supplementation had a small positive effect on cognitive development (SMD 0.21, 95% CI 0.03 to 0.38). The optimal benefit emerged at a DHA/ARA ratio of 0.5 to 1, where both Mental Development Index (WMD 0.55) and Psychomotor Development Index (WMD 0.48) showed significant improvement. This provides practical guidance on formulation ratios for infant DHA supplementation and reinforces the neurodevelopmental evidence for DHA in early life.

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