Guide to the Arachidonic Acid / EPA Ratio

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

The ratio of arachidonic acid (AA) to eicosapentaenoic acid (EPA) measures the pro-inflammatory (AA) and anti-inflammatory (EPA) fatty acids in your body to indicate your overall inflammatory status.

Why It Matters

The AA/EPA ratio provides a window into your body's inflammatory balance. AA tips the scale toward inflammation, while EPA helps counterbalance it. Your body needs both for proper function, but the ratio between them is important.

This balance affects everything from heart health to brain function. When the ratio is too high (too much AA compared to EPA), it creates an overly inflammatory environment that can contribute to chronic diseases. When the ratio is lower, it supports healthy immune function and tissue repair.

This marker can help identify inflammation-related health risks before they become serious problems and guide treatment approaches for existing conditions.

Associated Symptoms

The AA/EPA ratio itself is a laboratory finding rather than a medical condition. However, abnormal levels may be associated with various health issues, each with its own symptoms.

Common symptoms that may indicate conditions associated with a high AA/EPA ratio:

• Joint pain and stiffness: May result from increased inflammatory processes in joint tissues
• Skin problems: May include rashes, dryness, or excessive oil production due to inflammatory imbalance
• Mood disorders: May manifest as depression or anxiety related to neuroinflammation
• Fatigue: May develop from chronic low-grade inflammation taxing the body's energy systems
• Poor recovery from exercise: May occur as inflammatory processes delay tissue repair and recovery
• Digestive issues: May include bloating, discomfort, or irregular bowel movements from gut inflammation
• Cardiovascular concerns: May present as elevated blood pressure or impaired vascular function
• Allergic tendencies: May become more pronounced due to heightened inflammatory responses
• Brain fog: May result from neuroinflammation affecting cognitive function
• Sleep disturbances: May develop from inflammatory cytokines disrupting sleep regulation
• Slow wound healing: May occur when excessive inflammation interferes with normal repair processes

Symptoms that may indicate conditions associated with an extremely low AA/EPA ratio (rare):

• Excessive EPA supplementation: May cause fishy aftertaste or digestive discomfort
• Immune system suppression: May lead to increased susceptibility to infections
• Increased tendency for bleeding: May result in easier bruising or prolonged bleeding time
• Slow wound healing in extreme cases: May occur when insufficient inflammatory response impairs the initial stages of tissue repair

It's important to note that many people with an elevated AA/EPA ratio may experience no noticeable symptoms at all, especially with mild imbalances. The pattern, severity, and progression of symptoms, combined with laboratory findings, may help healthcare providers determine the underlying cause.

Clinical Ranges

Lab Reference Range: 3.7-40.7

Lifestyle Factors That Can Impact It

Activities that may have a positive effect on the AA/EPA ratio include:

• Regularly fatty fish consumption provides direct EPA, helping to lower the ratio and reduce inflammation.
• A Mediterranean diet rich in olive oil and fish helps maintain optimal ratios through balanced fatty acid intake.
• Moderate regular exercise improves metabolism and helps maintain a healthy inflammatory balance.
• Good sleep habits support proper hormone regulation and inflammatory balance.
• Stress management techniques help maintain healthy cortisol levels, which can affect inflammatory balance.
• Anti-inflammatory foods like fruits and vegetables provide compounds that help maintain healthy ratios.

Other habits can negatively affect levels, such as:

• Grain-fed meat consumption provides higher levels of AA compared to grass-fed alternatives.
• Intense exercise without recovery temporarily increases the ratio through inflammation and stress response.
• Excessive alcohol consumption damages liver function and increases inflammation.
• Smoking increases oxidative stress and inflammation, leading to higher ratios.

Other Factors That Can Impact It

While the below can have an effect through inflammation, diet is the primary determinant of levels.

Medical Conditions

• Inflammatory diseases: increase ratio by boosting AA relative to EPA
• Metabolic syndrome: raises ratio through inflammation
• Digestive disorders: affect ratio through changes in how you absorb nutrients and inflammation
• Autoimmune conditions: typically increase ratio
• Liver dysfunction: affects ratio through altered metabolism

Supplements

• Fish oil: Can decrease ratio by providing EPA
• Omega-6 supplements: Can increase ratio by raising amounts of AA

Testing Accuracy and Stability

AA/EPA ratio tends to be relatively stable over time but can be influenced by dietary changes and other factors.

Factors That Can Affect the Accuracy of Your Test

• Recent meals can temporarily affect levels. You should fast 9-12 hours before testing.
• Recent intense exercise can temporarily alter the ratio by increasing production of AA.
• Taking omega-3 supplements before the test can increase the ratio by raising EPA.
• Acute illness can affect ratio temporarily by increasing inflammation.

How It Relates to Other Markers

Your healthcare providers will often review your AA/EPA ratio alongside other markers to get a complete picture of your inflammatory status and overall health. These other tests might include:

• Omega-3 index: This marker shows your overall omega-3 status and helps confirm whether a high AA/EPA ratio is due to low EPA or high AA levels.
• DHA levels: Testing levels of docosahexaenoic acid (DHA), another omega-3, alongside the AA/EPA ratio helps evaluate overall omega-3 metabolism and indicates whether low EPA is part of a broader omega-3 deficiency.
• High-sensitivity C-reactive protein: This inflammatory marker helps confirm whether a high AA/EPA ratio is actively contributing to systemic inflammation.
• Lipid panel: Cholesterol and triglyceride levels are often analyzed with the AA/EPA ratio to help assess cardiovascular risk and metabolic health.
• Fasting insulin and glucose: These markers help evaluate whether a high AA/EPA ratio is associated with metabolic dysfunction. Insulin resistance can be associated with inflammation imbalance.
• Vitamin D: Low vitamin D levels can make inflammation worse. So this marker helps interpret whether vitamin D deficiency might be contributing to an elevated AA/EPA ratio.
• Complete blood count: White blood cell counts can help determine if an elevated AA/EPA ratio is associated with active inflammation or infection.
• Homocysteine: This marker of cardiovascular risk is typically used with the AA/EPA ratio to help assess overall inflammatory burden.
• IL-6 and TNF-alpha: These inflammatory markers can help determine if an elevated AA/EPA ratio is actively contributing to chronic inflammation.

Follow-up Considerations

Your healthcare provider will recommend appropriate follow-up based on your results and overall health status. This might include repeat testing, further testing, and additional care. You should always speak to your doctor if you have medical questions or before making medical decisions.

Additional Testing Your Doctor May Consider

• Borderline elevation: Inflammatory markers and lipid panel
• Moderate elevation: Full cardiovascular workup and inflammatory assessment
• Severe elevation: Comprehensive inflammatory panel and autoimmune screening

Further Reading

Why omega 3s are crucial to strong metabolic health

Bibliography