Nutrition and hypertension

Nutritional supplementation with anti-oxidant vitamins such as Vitamin C and E or with B vitamins such as Vitamin B6, can lower blood pressure in persons with essential hypertension. These nutritional supplements may act to prevent one of the underlying causes of essential hypertension, elevated tissue aldehydes. In essential hypertension, excess endogenous aldehydes bind sulfhydryl groups of membrane proteins, altering membrane Ca2+ channels and increasing cytosolic free calcium and blood pressure. Abnormalities in carbohydrate metabolism may underlie the etiology of the clinical course of hypertension. Insulin resistance and glucose intolerance is a common feature of hypertension in human and in animal models. Elevated endogenous aldehydes in hypertension may be due to increased production of reactive aldehydes such as methylglyoxal, when the glycolytic pathway of glucose metabolism is impaired. In hypertension there is increased oxidative stress which can lead to a further increase in reactive aldehydes. The thiol compound, N-acetylcysteine, normalizes elevated blood pressure by binding excess endogenous aldehydes and normalizing vascular Ca2+ channels and cytosolic free calcium. Vitamin C, vitamin E, vitamin B6 and lipoic acid are nutrients which can increase endogenous cysteine and glutathione. Dietary supplementation with these nutrients may improve carbohydrate metabolism, lower blood pressure and normalize associated biochemical and histopathological changes. (C) 2002 Elsevier Science Inc. All rights reserved.