Protecting Blood Vessels From Stress

Antioxidants May Prevent Inflammation When Combined With Amino Acid

Jan. 15, 2003 -- Antioxidants may help reduce normal wear and tear on your blood vessels and reduce the risk of potentially dangerous inflammation and blockages. New research shows that vitamins can improve blood flow and prevent the long-term development of atherosclerosis -- or hardening of the arteries -- when given in combination with an amino acid known as L-arginine.

Antioxidants, such as vitamins A, B, C, and E, are found in many fruits and vegetables. Although previous studies have suggested that the nutrients might protect against heart disease, recent research has cast doubt on some of those initial claims.

But this study, published in the Jan. 13 early edition of the Proceedings of the National Academy of Sciences, shows that antioxidants might work together with L-arginine to prevent inflammation in the branch areas of blood vessels.

Researchers say narrowing of the arteries most often begins in these areas because they are subject to the greatest stresses from blood rushing around their tight corners, like water gradually eroding a riverbank. These cells eventually may become damaged from the rushing forces and cause potentially dangerous inflammation within the blood vessel, leading to the atherosclerosis.

But researchers found that human cells exposed these to this type of stress in the lab were less likely to cause inflammation after a dose of antioxidants and L-arginine. Instead, the cells produced more of a substance that encourages healthy blood flow and prevents clotting. They also stopped accumulating certain proteins that are thought to promote atherosclerosis.

Researcher Louis J. Ignarro, PhD, of UCLA and colleagues say the role of antioxidants in the development of hardening of the arteries and heart disease remains unresolved, with some studies showing a benefit and others not.

However, this study shows that although antioxidants may not reverse or repair pre-existing damage within blood vessels, they may slow the long-term progression of atherosclerosis, and more research is need to see if use of antioxidants in young adults might prevent the disease in later life.