Reuven Zimlichman and colleagues at the Wolfson Medical Center in Israel said the study involved 70 patients from the center's hypertension clinic.
"Antioxidant supplementation significantly increased large and small artery elasticity in patients with multiple cardiovascular risk factors," Zimlichman said in a statement. "This beneficial vascular effect was associated with an improvement in glucose and lipid metabolism as well as significant decrease in blood pressure."
The research team randomized the 70 patients to receive either antioxidants or placebo capsules for six months.
The study, published in the journal Nutrition & Metabolism, found that at the three-month and six-month mark, patients in the antioxidant group had more elastic arteries -- a measure of cardiovascular health -- better blood sugar and better cholesterol profiles.