Omega-3 index test explained

The omega-3 index is a test that measures how much eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is present in the membranes of red blood cells (erythrocytes), compared with all the fatty acids found there. The result is expressed as a percentage. Because red blood cell membranes renew over several months, this indicator shows the average intake of omega-3 fatty acids over the past 2-3 months, rather than the momentary concentration in the blood, which depends more on the last meal. The test grew out of research that linked lower amounts of EPA and DHA in red blood cells with greater cardiovascular risk at population level. At present, however, there is no single internationally agreed reference range, approved by medical societies, that is applied as a diagnostic criterion. Omega-3 fatty acids (EPA, DHA) come mainly from oily fish (salmon, herring, mackerel) and fish oil supplements; the plant source of omega-3 - alpha-linolenic acid (ALA) - is converted into EPA and DHA only to a limited extent in the body.

• When you want to assess long-term intake of omega-3 fatty acids (fish, fish oil) from diet or supplements
• To assess whether taking extra omega-3 has actually changed the fatty acid composition in the body
• Alongside a lipid panel and a triglyceride test, when cardiovascular risk factors are being looked into
• For people who play sport or follow a specific diet and want to track the fatty acid balance in their body