What is Arachidonic Acid (Plasma)? High and low values | Lab results explained

Arachidonic acid (AA) is a 20-carbon polyunsaturated n-6 fatty acid with 4 double bonds (20:4n6). Its double bonds contribute to cell membrane fluidity and predispose it to oxygenation. This can lead to several important metabolites which ensure a properly functioning immune system as well as regulate inflammation, brain activity, and other signaling cascades.

Arachidonic acid (AA)‘s metabolites are called eicosanoids which are signaling molecules. They can be produced via
cyclooxygenases, lipoxygenase, cytochrome P450, and oxygen species-triggered reactions. These
pathways yield molecules like prostaglandins, isoprostanes, thromboxane, leukotrienes, lipoxins, and epoxyeicosatrienoic acids.

Arachidonic acid (AA) can be obtained in the diet from eggs, fish, and animal meats and fats – or produced directly from DGLA using the delta-5-desaturase enzyme. Although often vilified, adequate AA intake is needed to achieve an equilibrium between its inflammatory and resolution effects to support a healthy immune system. It is also fortified in infant formulas due to its importance in growth and

Arachidonic acid (AA) plays a crucial role in regulating innate immunity and inflammation resolution. When tissues become inflamed or infected, AA metabolites (eicosanoids) amplify those inflammatory signals to recruit leukocytes, cytokines, and immune cells to aid in pathogen resistance and clearance.

Following the initial inflammatory signaling, these metabolites then balance those signals by producing resolving metabolites for host protection.

High Levels:

Dietary intake of animal meats, fats, and eggs contribute to elevated levels. Arachidonic acid (AA) can also be produced from DGLA using the delta-5-desaturase enzyme, therefore high intake of omega-6 fatty acids or DGLA supplementation should be considered as a cause of elevations.

Arachidonic acid (AA) is then metabolized to docosatetraenoic acid using the elongase enzyme. Lack of vitamin and mineral cofactors, or a SNP in elongase, may slow the enzyme and contribute to elevations. It should also be noted that omega-3 and omega-6 fatty acids compete for use of the elongase and desaturase enzymes.

Because of its role in the inflammatory cascade and ability to induce oxidative stress, Arachidonic acid (AA) is a relevant factor in the pathogenesis of cardiovascular and metabolic diseases such as diabetes mellitus, non-alcoholic fatty liver disease, atherosclerosis, peripheral vascular disease, and hypertension. Neuroinflammation and brain excitotoxicity is also regulated by an AA cascade.

Elevations are associated with Alzheimer’s disease and mood disorders. There is also a substantial correlation between COX-catalyzed AA peroxidation and cancer development (prostate, colon, and breast).

Low Levels:

Reduced intake of animal meats and fats, or low dietary intake of omega-6 fatty acids in general, can result in lower levels of Arachidonic acid (AA). Lack of vitamin and mineral cofactors for the desaturase and elongase enzymes upstream in omega-6 metabolism might contribute to lower levels.

Because of important immune and inflammatory signaling which requires Arachidonic acid (AA), and its role in cell membrane phospholipid metabolism, lower levels of Arachidonic acid (AA) do have clinical significance. Psychiatric disorders such as schizophrenia, and neurologic disorders like tardive dyskinesia, show depletion of AA in RBC membranes. Improving AA levels decreased symptoms in some patients.

Monitoring levels and ensuring adequate dietary intake of AA is important in pregnant women, infants, children, and the elderly due to its importance for the development and optimization of the nervous system, skeletal muscle, and the immune system.


Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

The information on is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: