A Randomized, Double-Blind, Placebo-Controlled Trial to Determine the Effectiveness of a Polyphenolic Extract (Hibiscus sabdariffa and Lippia citriodora) for Reducing Blood Pressure in Prehypertensive and Type 1 Hypertensive Subjects.

Hypertension is an important factor of cardiovascular diseases and contributes to their negative consequences including mortality. The World Health Organization estimated that 54% of strokes and 47% of cases of ischemic heart illness are related to high blood pressure. Recently, Hibiscus sabdariffa (HS) and Lippia citriodora (LC) have attracted scientific interest, and they are recognized for their high content of polyphenols as these may prevent several disease factors, such as hypertension. The aim of the present study is to determine if supplementation with an HS-LC blend (MetabolAid®) may be effective for the treatment of type 1 hypertensive sedentary populations. A total of 80 type 1 hypertensive subjects of both sexes were included in the study and were treated with placebo or the HS-LC extract, and both groups were treated over 84 days. The blood pressure (diastolic, systolic, and pulse pressure) was measured throughout the day, for each of the days of the study duration and determined using Ambulatory Blood Pressure Monitoring (ABPM). Physical activity was determined throughout the study to ensure similar conditions related to exercise. The results showed the capacity for reducing the blood pressure parameters in the case of the HS-LC extract. The daily consumption of the HS-LC extract but not the placebo over 84 days was able to reduce the daytime parameters related to blood pressure. The most remarkable results were observed in the measurements performed during the daytime, especially in the systolic blood pressure showing statistically significant variation.

Effect of Dietary Supplementation with a Natural Extract of Sclerocarya birrea on Glycemic Metabolism in Subjects with Prediabetes: A Randomized Double-Blind Placebo-Controlled Study.

A randomized, double-blind, placebo-controlled study was conducted with the primary objective of assessing the effect of a natural extract of Sclerocarya birrea on glucose metabolism in subjects with prediabetes. The duration of the study was 90 days. Thirty-three subjects assigned to the experimental group (daily ingestion of 100 mg of the nutraceutical product) and 34 assigned to the placebo group completed the study. There were 36 men and 31 women with a mean age of 32.3 ± 14.1 years. In the area under the curve (AUC) of the oral glucose tolerance test (OGTT), statistically significant decreases in the experimental group at 40 and 90 days as compared with baseline were found, whereas significant changes in the placebo group were not observed. Within-group differences were statistically significant in favor of the experimental group for glucose peak at OGTT, serum insulin, insulin resistance markers, and flow-mediated dilation. Changes in lipid and anthropometric parameters were not observed, although there was a trend for lower cholesterol levels and a decrease in body weight in the experimental group. Decreases in systolic blood pressure were also higher among subjects in the experimental group. This exploratory study confirms the antidiabetic activity of Sclerocarya birrea in prediabetes. Further studies using better measurements of beta-cell function are needed to clarify the underlying mechanisms of the hypoglycemic effect of this natural compound.

Pomegranate Extract Improves Maximal Performance of Trained Cyclists after an Exhausting Endurance Trial: A Randomised Controlled Trial.

The efficacy of pomegranate (Punica granatum) extract (PE) for improving performance and post-exercise recovery in an active population was equivocal in previous studies. In this study, a randomised, double-blinded, placebo-controlled, balanced, cross-over trial with two arms was conducted. Eligibility criteria for participants were as follows: male, amateur cyclist, with a training routine of 2 to 4 sessions per week (at least one hour per session). The cyclists (n = 26) were divided into treatment (PE) and placebo (PLA) groups for a period of 15 days. After physical tests, the groups were exchanged after a 14-day washout period. Exercise tests consisted of endurance bouts (square-wave endurance exercise test followed by an incremental exercise test to exhaustion) and an eccentric exercise drill. The objective was to assess the efficacy of PE in performance outcomes and post-exercise muscular recovery and force restoration after a prolonged submaximal effort. Twenty-six participants were included for statistical analysis. There was a statistically significant difference in total time to exhaustion (TTE)(17.66⁻170.94 s, p < 0.02) and the time to reach ventilatory threshold 2 (VT2)(26.98⁻82.55 s, p < 0.001), with greater values for the PE compared to the PLA group. No significant results were obtained for force restoration in the isokinetic unilateral low limb test. PE, after a prolonged submaximal effort, may be effective in improving performance outcomes at maximal effort and might help to restore force in the damaged muscles.