A Polish study in healthy volunteers showed that eleuthero (Eleutherococcus senticosus) was more effective than echinacea in improving parameters of cardiovascular health, fitness and immune function after 30 days of treatment. The 50 study participants were randomly divided into two groups and treated with the elethero preparation or the echinacea preparation. The elethero group had statistically significant reductions in levels of total cholesterol, low density lipoprotein (LDL) cholesterol, free fatty acids, triglycerides, and glucose compared with the echinacea group. There was also a statistically significant difference in immune system function among those taking eleuthero, as demonstrated by tests of phagocytic activity and spontanious blastic formation of lymphocytes, but only insignificant changes in numbers of lymphocytes able to stimulate cytokine production. In addition, spirometric tests of physical fitness were performed, those taking eleuthero showed statistically significant increases in maximal oxygen uptake after thirty days of treatment, compared with no change in the echinacea group.