Dr. Grey AI

Essential fatty acid (EFA)

Essential fatty acids (EFAs) are polyunsaturated fats that humans cannot synthesize and must obtain from diet. Two families exist: omega-3 (alpha-linolenic acid/ALA) and omega-6 (linoleic acid/LA). NO GRADED OUTCOMES in this database - see specific supplements (fish oil, omega-3, omega-6) for evidence. Omega-3s (EPA, DHA) have extensive cardiovascular and anti-inflammatory evidence. Most Western diets are omega-6 heavy; increasing omega-3 intake is generally recommended. The omega-6:omega-3 ratio matters for inflammation balance. Deficiency is rare but causes dermatitis, poor wound healing, and growth impairment.

Quick Answer

What it is

Essential fatty acids (EFAs) are polyunsaturated fats that humans cannot synthesize and must obtain from diet. Two families exist: omega-3 (alpha-linolenic acid/ALA) and omega-6 (linoleic acid/LA).

Key findings

  • Grade C: ADHD Symptoms
  • Grade C: Dry Eye Symptoms
  • Grade C: Cardiovascular Risk Markers

Safety

  • A narrative review linked low essential fatty acid intake (particularly omega-3 deficiency during caloric restriction and dieting) to increased risk of depression, noting that EFA-depleted diets may impair serotonergic neurotransmission.
ℹ️ Quick Facts: Essential fatty acid (EFA)

Quick Facts: Essential fatty acid (EFA)

  • Best Evidence:Grade C
  • Conditions Studied:5
  • Research Outcomes:12
  • Key Effect:Attention Deficit Hyperactivity Disorder (ADHD)
Outcomes by grade:
A0
B0
C3
D9
5 conditions · 12 outcomes

Detailed Outcomes

Grade:
Effect:
Size:
Sort:
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C
ADHD Symptoms
A systematic review of clinical trials found that children with ADHD tend to have lower EFA levels, and some supplementation trials showed modest improvements in ADHD-related symptoms, though results were inconsistent across studies and effect sizes were generally small.
small↓Improves
C
Dry Eye Symptoms
Two narrative reviews synthesized evidence from multiple clinical studies suggesting that essential fatty acid supplementation (both omega-3 and omega-6, particularly GLA and EPA/DHA) can improve tear film stability, reduce ocular surface inflammation, and alleviate dry eye symptoms.
moderate↓Improves
D
Tardive Dyskinesia Symptoms
Two reviews examined the relationship between essential fatty acid status and tardive dyskinesia in schizophrenia patients, reporting that EFA deficits are common in these patients and that supplementation may have modest therapeutic potential, though controlled trial data remain limited.
small↓Improves
D
Infant Visual Development
A clinical study in malnourished nursing infants found that dietary long-chain EFA supplementation improved visual evoked potential responses, and separate research confirmed that preterm infants have lower EFA status in umbilical vessel walls compared to full-term infants.
moderate↑Improves
D
EFA Deficiency in GI Disorders
Clinical studies found a high prevalence of essential fatty acid deficiency in patients with chronic gastrointestinal disorders and cystic fibrosis, suggesting that targeted EFA supplementation may correct biochemical deficiency markers in these populations.
moderate↓Worsens
D
Atopic Dermatitis Symptoms
A small randomized crossover trial found that dietary hempseed oil, rich in both omega-3 and omega-6 EFAs, improved skin dryness, itchiness, and reduced the use of dermal medications in patients with atopic dermatitis over 8 weeks.
moderate↓Improves
D
Depression Risk
A narrative review linked low essential fatty acid intake (particularly omega-3 deficiency during caloric restriction and dieting) to increased risk of depression, noting that EFA-depleted diets may impair serotonergic neurotransmission.
small↓Improves
D
Multiple Sclerosis Symptoms
A clinical trial found that co-supplementation with hemp seed and evening primrose oils (providing balanced omega-3 and omega-6 EFAs) alongside a hot-nature diet showed immunomodulatory and therapeutic effects in multiple sclerosis patients, including reduced relapse rates.
moderate↓Improves
C
Cardiovascular Risk Markers
Reviews and mechanistic studies suggest that EFAs may function as endogenous HMG-CoA reductase inhibitors, ACE enzyme inhibitors, and anti-arrhythmic agents. Combined omega-3 and omega-6 supplementation improved blood rheology markers in small human trials, supporting a 'polypill' hypothesis for cardiovascular protection.
moderate↓Improves
D
White Blood Cell Aggregation
A small clinical trial in healthy volunteers found that dietary supplementation with combined omega-3 and omega-6 fatty acids reduced induced white blood cell aggregation, suggesting improved microvascular flow properties.
small↓Improves
D
Red Blood Cell Rheology
A small human trial found that combined omega-3 and omega-6 EFA supplementation improved red blood cell deformability and rheological properties, which may support microcirculation.
small↑Improves
D
Bone Mineral Density
In a rat model, the ratio of n-6 to n-3 essential fatty acids significantly affected calcium balance and bone parameters, with lower n-6/n-3 ratios associated with improved calcium absorption and bone mineral content.
small↑Improves

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