Wine grape pomace flour improves blood pressure, fasting glucose and protein damage in humans: a randomized controlled trial.
BACKGROUND
The Mediterranean diet is a healthy diet with positive scientific evidence of preventing chronic diseases. Bioactive components support the healthy properties of the Mediterranean diet. Antioxidants and fiber, two components of the Mediterranean diet, are key functional nutrients for healthy eating and nutrition. Wine grape pomace is a rich source of these dietary constituents and may be beneficial for human health. Our hypothesis was that the intake of red wine grape pomace flour (WGPF) prepared from red wine grapes (Cabernet Sauvignon variety) reduced the metabolic syndrome in humans. To evaluate the effect of WGPF on components of metabolic syndrome we design a 16-week longitudinal intervention study. Thirty-eight males, 30-65 years of age, with at least one component of metabolic syndrome, were randomly assigned to either the intervention group (n = 25) or the control group (n = 13). At lunch, the intervention group was given 20 g of WGPF per day, which contained 10 g of dietary fiber, 822 mg of polyphenols and an antioxidant capacity of 7258 ORAC units. Both groups were asked to maintain their regular eating habits and lifestyles. Clinical evaluation, anthropometric measurements and biochemical blood analyses were done at the beginning and the end of the study.


RESULTS
WGPF intake significantly decreased systolic and diastolic blood pressure as well as fasting glucose levels. Plasma γ-tocopherol and δ-tocopherol increased and carbonyl group in plasma protein decreased in WGPT group, significantly. No significant effect was observed for waist circumference, HDL cholesterol, triglycerides, total antioxidant capacity and vitamin C in and between groups. The group-dependent magnitude of the differences between the baseline and final postprandial insulin values and γ-tocopherol concentrations was statistically significant.


CONCLUSIONS
The consumption of WGPF-rich in fiber and polyphenol antioxidants, as a food supplement in a regular diet improves blood pressure, glycaemia and postprandial insulin. In addition, increased antioxidant defenses and decreased oxidative protein damage indicating attenuation of oxidative stress. WGPF might be a useful food ingredient for health promotion and chronic disease prevention.
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. iurquiaga@bio.puc.cl.
Inés
I
Urquiaga
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. soniadacu@gmail.com.
Sonia
S
D'Acuña
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. dperez.pons@gmail.com.
Druso
D
Pérez
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. saradicenta@opalum.es.
Sara
S
Dicenta
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. gecheverria@bio.puc.cl.
Guadalupe
G
Echeverría
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. arigotti@med.puc.cl.|Departamento de Nutrición, Diabetes y Metabolismo, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile. arigotti@med.puc.cl.
Attilio
A
Rigotti
Centro de Nutrición Molecular y Enfermedades Crónicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Avenida del Libertador Bernardo O'Higgins 340, Santiago, Chile. fleighton@bio.puc.cl.
Federico
F
Leighton
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D016022:Case-Control Studies; D038441:Diet, Mediterranean; D004043:Dietary Fiber; D002149:Energy Intake; D005215:Fasting; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D024821:Metabolic Syndrome / Q000517:prevention & control*; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D014920:Wine
D001786:Blood Glucose; D004043:Dietary Fiber