A randomized double blinded placebo controlled trial of a nutraceutical preparation. Up to 60 men and women between the ages of 50 and 70, and generally healthy will participate in this study. . Up to 30 participants will receive the nutritional supplement and up to 30 will receive placebo.

Potential participants will be screened by telephone and have the study explained to them in detail. If they qualify and choose to participate they will come in for the first of three visits. Informed consent will be obtained and demographic information collected. Information requested on the demographic form includes ethnicity, income, education, marital status, smoking and alcohol use, and exercise habits. Next they will have blood pressure checked and if not within parameters they will be dropped from the study and informed that they need to follow up the abnormal result with their health care provider. Those that pass these screening tests will have 15 to 25 cc's of peripheral blood (serum) collected by the study coordinator via venipuncture while at rest. They will then stretch for 2 minutes (60 seconds marching in place followed by 10 toe touches) followed by accelerating treadmill walking exercise. The exercise intervention will consist of a 15 minute period of walking on a treadmill. The treadmill will not be inclined during the intervention. The participants target heart rate will be determined by deducting their age from 220. They will start walking on the treadmill at a speed of 1.7 mph and the speed will be titrated as indicated to keep their heart rate at 50 to 90% of target. Heart rate will be monitored via the pulse oximetry feature of the Welch Allyn vital signs monitor. Blood pressure will be measured every 3 minutes during the exercise intervention and until they have returned to baseline (within 10 points) following cessation of the exercise protocol. The test will be stopped for any participant complaint of chest pain, excess fatigue, difficulty breathing, a blood pressure reading of more than 180/94, or a participant request. If symptoms increase or do not completely resolve with 15 minutes of rest the study coordinator will call 911 (through campus police) to activate the EMS response. If symptoms resolve completely within 15 minutes participants will be withdrawn from the study and advised to follow up with their health care provider. Any participant unable to complete the exercise intervention for any reason will be withdrawn from the study.

Five to fifteen minutes after the exercise intervention has been completed blood will again be collected in exactly the same manner as the resting sample. Participants will then receive a 2 week supply of either NutraStem or placebo and will be advised to take one tablet every morning and evening before meals for the next 2 weeks. If the participant is unable to complete any portion of the visit activities at any visit they will be withdrawn from the study due to their inability to complete the study. All visit activities will be recorded in detail on the visit session record.

The second visit will occur 2 weeks later and include a blood pressure check, an at rest blood draw, the exercise intervention, and then a repeat blood draw five to fifteen minutes after completion of the intervention. Participants will then receive a 2 week supply of either NutraStem or placebo and will be advised to take one tablet every morning and evening before meals for the next 2 weeks. I Participants will be advised to bring their empty pill containers to their next session so we can confirm they are taking the supplement as required. If the blood pressure is outside of the specified range they will be dropped from the study and no blood collection or study intervention will take place.

The third visit will be the same as the second visit.