Echinacea-based Supplement Does Not Improve Markers of Performance in Athletes

Overview

The purpose of this study was three-fold. We wanted to (1) determine if supplementation with an echinacea-based dietary supplement (ECH) would increase several blood parameters that could affect oxygen carrying capacity in the body, (2) determine if ECH would increase VO2max in trained endurance athletes, and (3) examine the effectiveness of two different doses of the ECH on all outcome variables. We hypothesized that supplementation with ECH would increase oxygen carrying capacity (as measured by RBCs, EPO, ferritin, hemoglobin (Hb), and hematocrit (Hct) levels), improve VO2max, and that the maximum dose would be most effective at increasing these outcomes.

The supplement industry is a multi-billion dollar industry with many of the products targeted toward athletes and achieving optimal performance. Historically, endurance athletes have used a number of methods to try to increase erythrocyte (red blood cell-RBC) production in attempts to boost oxygen carrying capacity and perform better during aerobic exercise. A number of growth factors in the body can stimulate RBC production including erythropoietin (EPO). EPO is the primary growth factor that promotes the formation and release of RBCs from bone marrow. Although EPO itself is a banned substance, supplement companies have sought other means by which they can increase EPO production in the body in order to stimulate RBC synthesis. One natural product toted to stimulate EPO production is Echinacea and can be found in the product EPO-Boost™. Our global hypothesis is that supplementation of EPO-Boost™ will be an effective way to increase oxygen carrying capacity and improve maximal oxygen consumption in adult endurance athletes. We will test whether EPO-Boost™ affects EPO levels, a number of blood parameters, and VO2max (maximal aerobic capacity) by recruiting 40 trained endurance athletes (20 males and 20 females). To be included, subjects must already be performing aerobic exercise at least 4 days per week for a minimum of one hour each day. Participants will be randomly assigned (within gender) to either the placebo (n=20) or supplement group (n=20). A 25% dropout rate may be expected in both genders, therefore we are recruiting a subject number of 40 participants to ensure that at least 30 subjects will complete the study. All participants will be blinded as to whether they are receiving the placebo or the supplement. Participants will report to the Human Nutrition Lab (HNL) and the Exercise Physiology Lab for baseline testing. Height, body weight, body composition, and blood samples will be obtained. Participants will then answer questions regarding their current and usual exercise patterns. These questions will address the type, frequency, duration, and intensity of exercise. Finally, participants will perform a VO2max test in the Exercise Physiology Lab. After baseline testing the participants will be given a supply of either EPO-Boost™ or placebo along with extra capsules. The subjects will not know whether they are receiving the product or the placebo. Participants will also be asked to consume a multivitamin pill daily for the entire 35-day intervention period. Finally, participants will be asked to keep an exercise log during the 35-day intervention documenting type, duration, intensity, and days of exercise in order for research personnel to ensure that exercise training is not changing. The capsule and exercise logs will be collected at days 14 and 35. Blood collected during all 3 visits will be analyzed for EPO, ferritin, RBCs, white blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration. We will assess changes in blood parameters and VO2max to determine whether 35 days of EPO-Boost™ supplementation improves blood parameters or maximal aerobic capacity compared to placebo controls.