Objective: To study the effects of a nutritional supplement on cardiovascular health determined by blood and saliva biochemistry and heart rate variability (HRV) in asymptomatic college students and faculty members.
Methods: Forty subjects were recruited in the study via a school wide email notification and through personal contacts. GreensFirst vegetable supplement drink was tested to document its effect on the blood and saliva biochemistry in relation to cardiovascular health.
Results: After taking the supplement for 90 days, both the systolic and diastolic blood pressure decreased significantly. The heart rate decreased but did not reach statistical significance. Time domain analysis of HRV showed a slight decrease in standard deviation of normal-normal and square root of the mean squared differences but did not reach statistical significance. Frequency analysis of HRV found no significant changes. Saliva dehydroepiandosterone sulfate (DHEA-S) and Cortisol decreased after taking the supplement, however, they did not reach significant levels. Blood glucose concentration was increased slightly but the change was not significant. Blood serum tests showed no significant changes in the total cholesterol or the low-density lipoprotein levels. However, it was noted that the high-density lipoprotein level was decreased significantly. Triglycerides did not show any significant changes but it were slightly elevated after the treatment period. Homocysteine increased significantly after taking the supplement for 90 days.
Conclusion: For this group of subjects, taking the green vegetable drink for 90 days reduced blood pressure but did not significantly affect the blood and saliva chemistry.