Increased blood pressure, even before clinically diagnosed as hypertension, is a significant risk factor for cardiovascular disease and stroke. Elevations of just 3 to 5 millimeters of mercury can dramatically raise the risk of a fatal heart attack or cerebrovascular event. Nearly 30 percent of US adults have high blood pressure or hypertension that places them at much higher risk for disease progression.
Researchers from the Johns Hopkins University School of Medicine have published the result of a study showing the importance of supplemental vitamin C to lower blood pressure in the American Journal of Clinical Nutrition. Lead study author, Dr. Peter R. Miller commented “Our research suggests a modest blood pressure lowering effect with vitamin C supplementation,” noting that vitamin C taken at higher doses than suggested by the recommended daily requirement effectively lowers blood pressure enough to lower risk of a heart attack or stroke.
The study involved a meta-analysis of 29 randomized, controlled and previously published clinical trials that reported systolic or diastolic blood pressure values and also compared vitamin C intake to a placebo. Many nutrition experts believe that large amounts of vitamin C, an essential micronutrient found primarily in fruits and vegetables, could lower blood pressure, but a formal study to test this hypothesis has been lacking.
Vitamin C supplementation effectively lowers blood pressure to help prevent stroke and heart disease
The researchers found that taking an average of 500 milligrams of vitamin C daily, about five times the recommended daily requirement, reduced blood pressure by 3.84 millimeters of mercury in the short term. Among those diagnosed with hypertension, the drop was nearly 5 millimeters of mercury. While these results may not sound dramatic, they can be sufficient to dramatically lower cardiovascular and stroke risk for the millions of adults diagnosed with mild hypertension.
Dr. Miller concluded “Although our review found only a moderate impact on blood pressure, if the entire U.S. population lowered blood pressure by 3 milliliters of mercury, there would be a lot fewer strokes.” The team noted that the blood pressure lowering effect of vitamin C supplementation was likely due to the nutrient’s biological and physiological effects. Vitamin C acts as a diuretic, causing the kidneys to remove more sodium and water from the body, which helps to relax the blood vessel walls, thereby lowering blood pressure.
Vitamin C is also known to improve essential endothelial function of delicate artery walls, effectively restoring elasticity and resolving micro-cracks in the vessels that lead to arterial plaque formation. Most nutrition experts recommend up to three grams of vitamin C supplementation per day for optimal protection from hypertension, cardiovascular disease and stroke.