The omega-3 index is defined as the RBC percentage sum of EPA+DHA, both of which are important antiinflammatory omega-3 fatty acids. This index was first proposed in 2004 as a cardiovascular risk factor by Dr. Willian S. Harris and Dr. Clemons von Schacky as a way of assessing risk for coronary artery disease and related death. Since then, it has been repeatedly verified as an important cardiovascular biomarker, and studied in other diseases including obesity, mood disorder, and insulin resistance.

A reasonable target for the omega-3 index is >8% to decrease disease risk. Drs. Harris and von Schacky stratified risk zones as high risk (8%). These percentages have been continually verified in outcome studies and risk assessment.

Dietary intervention to increase the omega-3 index should include oily fish, flax, walnut, and chia. Fish oil supplementation can also be considered.

References:

- Harris WS, Von Schacky C. The Omega-3 Index: a new risk factor for death from coronary heart disease? Preventive medicine. 2004;39(1):212-220.

- Harris WS. The omega-3 index: from biomarker to risk marker to risk factor. Curr Atheroscler Rep. 2009;11(6):411.

- Harris WS. The omega-3 index: clinical utility for therapeutic intervention. Current cardiology reports. 2010;12(6):503-508.

- Burrows T, Collins C, Garg M. Omega-3 index, obesity and insulin resistance in children. International Journal of pediatric obesity. 2011;6(sup3):e532-539.

- Baghai TC, Varallo-Bedarida G, Born C, et al. Major depressive disorder is associated with cardiovascular risk factors and low Omega-3 Index. The Journal of clinical psychiatry. 2010;72(9):1242-1247.

- Parletta N, Zarnowiecki D, Cho J, et al. People with schizophrenia and depression have a low omega-3 index. Prostaglandins, Leukotrienes and Essential Fatty Acids. 2016;110:42-47.

- Albert BB, Derraik JG, Brennan CM, et al. Higher omega-3 index is associated with increased insulin sensitivity and more favourable metabolic profile in middle-aged overweight men. Scientific reports. 2014;4:6697.

- von Schacky C. Omega-3 index in 2018/19. Proceedings of the Nutrition Society. 2020:1-7.

- Aarsetoey H, Aarsetoey R, Lindner T, Staines H, Harris WS, Nilsen DWT. Low Levels of the Omega-3 Index are Associated with Sudden Cardiac Arrest and Remain Stable in Survivors in the Subacute Phase. Lipids. 2011;46(2):151- 161.