Researchers from the University of California at Irvine College of Medicine have found a connection between oxidative stress and high blood pressure. Their results were published in the journal, Hypertension (2000;36(1):142-1). Oxidative stress has already been linked to inflammation and heart diseases. Oxidative stress can reduce the levels of nitric oxide thereby increasing blood pressure. Antioxidant vitamins in the diet can reduce blood pressure. The researchers found that rats who had diets that increased oxidative stress.

This was an animal study. The researchers increased the oxidative stress in rats by decreasing glutathione—a natural, water-soluble antioxidant. The rats with lower glutathione levels also had lower levels of nitric oxide, which in turn increased blood pressure. The researchers also found that the combination of the antioxidant vitamins C and E in the diet helped to reduce the blood pressure.

Dr. Nostratola Vaziri, professor of medicine, leader of the research team noted that while the antioxidant nutrients lowered blood pressure, they did not restore it to normal. Dr. Viziri stated that this is an indication that the nutrients only play a partial role in blood pressure regulation.

Other research has indicated that antioxidant nutrients can help with blood pressure. For example, Researchers at Boston University School of Medicine and the Linus Pauling Institute at Oregon have shown that vitamin C supplementation can lower blood pressure, possibly because of this antioxidant activity. This was published in the Lancet (Volume 354, Number 9195; 11 December 1999).