Treatment Monitoring: Omega 3 Fatty Acid Supplementation

The Blood Viscosity Test can be used as a diagnostic tool for pre-screening and monitoring patients receiving dietary supplementation with omega-3 fatty acids (or fish oil).  

Fish oil supplements (i.e., eicosopentaenoic acid or EPA) have been shown in a double-blind, randomized study to lower Systolic Blood Viscosity (blood thickness) and Diastolic Blood Viscosity (blood stickiness) both by 15%.  Five capsules were given twice daily for seven weeks (1.8 g/day), and Blood Viscosity Tests were performed at the beginning of the study and at the end of seven weeks of supplementation [1]. 

No significant changes were observed in hematocrit or plasma viscosity despite the Systolic and Diastolic Blood Viscosity reductions of 15%, suggesting that the benefit of fish oil supplements to circulatory health may be due, at least in part, to increases of EPA content in red cell membranes, which in turn reduce blood viscosity. 

Dietary supplementation with omega-3 fatty acids (or fish oil) has been previously shown to be effective in prevention of cardiovascular events.  One major study of 11,324 patients following a recent heart attack showed that fish oil supplements reduced the incidence of death, cardiovascular death, and sudden cardiac death by 20%, 30%, and 45%, respectively. [2] 

The Blood Viscosity Test is the only available diagnostic measure for the thickness and stickiness of blood and may be employed as a tool for direct monitoring of treatments that improve blood circulation and perfusion. 

Meridian Valley Lab’s Blood Viscosity Test enables doctors to pre-screen patients who may benefit from omega-3 supplementation but are asymptomatic. 

Important Information

The Blood Viscosity Test is performed at Meridian Valley Lab using a calibrated glass capillary system that is classified as a Class I device under 21 CFR § 862.2920.  The Blood Viscosity Test is not covered by insurance plans.  Doctors must bill their patients or their patients’ caregivers for this service. 



1. Woodcock BE, et al. Beneficial effect of fish oil on blood viscosity in peripheral vascular disease. Br Med J (Clin Res Ed). 1984 Feb 25;288(6417):592-4.
2. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Lancet. 1999 Aug 7;354(9177):447-55.
3. Simopoulos AP. Omega-3 fatty acids and athletics. Curr Sports Med Rep. 2007 Jul;6(4):230-6.
4, Johnson AG. Modulation of the immune system by synthetic polynucleotides. Springer Semin Immunopathol. 1979:2:149-168.