Vitamin E Protects Circulatory, Kidney Health

BOSTON--Consuming antioxidants, specifically vitamin E, can prevent the adverse events typically associated with salt intake, which increases oxidative stress, according to researchers from the Whitaker Cardiovascular Institute at Boston University School of Medicine. Their animal study, published in the July issue of the Journal of Cardiovascular Pharmacology (42, 1:82-88, 2003) (www.cardiovascularpharm.com), indicated that by reducing oxidative damage, salt-dependent hypertension and nephropathy (kidney disease) could be prevented.

Hypertension is a risk factor for the development of end-stage kidney disease, although not all patients with high blood pressure develop kidney dysfunction, according to the researchers. Their explanation for this discrepancy was that, while mechanisms underlying hypertensive nephropathy are not well understood, an accumulation of reactive oxygen species generally accompanies the development of hypertension and renal dysfunction.

To investigate this occurrence, researchers studied the effects alpha-tocopherol had on the development of salt-dependent hypertensive nephropathy in rats. Animals fed a high-salt diet developed hypertension and exhibited an increase in renal oxidative stress. However, rats fed a high-salt diet as well as vitamin E did not exhibit these adverse effects. Researchers concluded, "[T]hese findings suggest that, in the [salt-sensitive] rat, salt-dependent hypertensive nephropathy and decreased nitric oxide bioavailability are associated with increased oxidative stress, and that antioxidants can preclude these adverse effects of salt feeding and, consequently, prevent salt-dependent hypertension and nephropathy."