It's no secret that vascular health declines with age. Contributing to this decline is dysfunction of the endothelium, the inner lining of the blood vessels. Normally, a functional endothelium enables coagulation, platelet adhesion and immune activity. However, its dysfunction is associated with reduced anticoagulant properties and an inability of arteries and arterioles to dilate fully, which contribute to the development of various diseases, especially cardiovascular disease. Endothelial dysfunction also reduces exercise capacity with age.

Previous studies have suggested that dietary intake of polyphenols (compounds found in fruit- and vegetable-derived foods and beverages, including red wine) lessens the risk of cardiovascular disease and that this effect may be exerted through direct action of polyphenols on endothelial cells.

Credit: Valentin Casarsa

In a new study published in (Biochemical and Biophysical Research Communications 404, 743–749; 2011), Valérie B. Schini-Kerth (Université de Strasbourg, Illkirch, France) and colleagues examined whether red wine polyphenols could prevent aging-induced endothelial dysfunction and decline in physical performance. Two different dosages of red wine polyphenols were administered in drinking water to male Wistar rats from age 16 weeks to age 40 weeks; vascular reactivity was assessed at ages 12 weeks, 20 weeks and 40 weeks. Schini-Kerth's group found that administration of red wine polyphenols improved the aging-related impairment of vascular relaxation and aging-related vascular oxidative stress. They also found that the higher dosage of red wine polyphenols improved the aging-related reduction in exercise capacity.

This work suggests that intake of red wine polyphenols prevented aging-related endothelial dysfunction and also improved the exercise capacity of aged rats. These benefits seem to involve the ability of red wine polyphenols to reduce oxidative stress by inhibiting the enzyme NADPH oxidase, which is associated with the hardening of arteries and an increased risk of heart disease. According to the authors, “[t]he beneficial effect of [red wine polyphenols] is explained best by their ability to maintain oxidative stress in the old arterial wall to a level similar as that observed in young arteries.”

In this study, red wine polyphenols were administered to rats that were relatively young. In a review of the study, independent experts from the International Scientific Forum on Alcohol Research note that some previous studies suggest that interventions to improve endothelial function (such as consumption of polyphenols) should begin early in life to slow aging-related endothelial dysfunction. These results tend to support this notion.