Plasma Matrix Metalloproteinase (MMP)-9 Levels Are Reduced following Low-Calorie Cranberry Juice Supplementation in Men

Abstract

Objective: Matrix metalloproteinase (MMP)-9, also known as gelatinase B, is implicated in the development of hypertension and atherosclerotic plaque vulnerability to rupture, an important step in the etiology of cardiovascular diseases. Studies have suggested that flavonoid consumption may be cardioprotective, and its favorable impact on circulating MMP-9 concentrations could partly explain this association. The aim of the present study was to determine the effect of consuming increasing daily doses of low-calorie cranberry juice cocktail (CJC) on plasma MMP-9 concentrations of abdominally obese men.

Methods: Thirty men (mean age ± SD: 51 ± 10 years) consumed increasing doses of CJC during 3 successive periods of 4 weeks (weeks 1–4: 125 ml/day, weeks 5–8: 250 ml/day, and weeks 9–12: 500 ml/day). Before the study and after each phase, a series of physical and metabolic variables were measured, including MMP-9.

Results: We found that CJC supplementation significantly decreased plasma MMP-9 concentrations (mean ± SEM: −36% ± 9%, p < 0.0005; week 12 vs. baseline) while baseline plasma MMP-9 concentrations strongly correlated with the changes noted over the entire intervention (r  =  −0.71, p < 0.0001). We also show that the reduction in plasma MMP-9 levels was associated with a change in plasma nitrites/nitrates (NOx) concentration over the entire intervention (r  =  −0.38, p < 0.05; week 12 vs. baseline). Significant correlations were also noted between changes in plasma MMP-9 levels and those of systolic (r  =  0.39, p < 0.05) and diastolic (r  =  0.60, p < 0.001) blood pressure during the course of the study (week 12 vs. baseline).

Conclusions: Our results show that daily CJC consumption is associated with a decrease in plasma MMP-9 concentrations in abdominally obese men. We hypothesize that polyphenolic compounds from cranberries may be responsible for this effect, supporting the notion that the consumption of flavonoid-rich foods can exert cardioprotective effects.

• cranberry
• flavonoids
• cardiovascular disease
• MMP-9

This study was supported by an unrestricted grant from the Canadian Cranberry Growers Coalition. Guillaume Ruel is the recipient of a doctoral training award from the Fonds de la recherche en santé du Québec (FRSQ). Charles Couillard and Patrick Couture are research scholars from the FRSQ. Benoît Lamarche holds a Canada Research Chair in Nutrition and Cardiovascular Health. Charles Couillard is also supported by the Chair in Nutrition and Cardiovascular Health of Laval University.

The authors would like to thank Marge Leahy, PhD, and Robin Roderick, MSc, from Ocean Spray Cranberries Inc. for kindly assessing the composition of CJC and placebo as well as supervising the packaging sessions at Laval University. We also acknowledge the contributions of Danielle Aubin (RN) as well as Mélanie Martineau, Jocelyne Giasson, Raoul Géra, Pascal Cliche, and Bernard Béliveau (Food Transformation Laboratory, Laval University). Finally, we would like to thank the subjects who participated in this study, without whom no clinical research would be possible.