The strong relationship between diet and blood pressure and the risk of hypertension has been well recognized. Currently, three specific diet-related factors have been recommended by the Joint National Committee on High Blood Pressure as a first-line approach in preventing and treating hypertension: caloric restriction for weight reduction, reduced consumption of alcohol, and lower sodium intake. Many studies, primarily observational, have shown significant associations between blood pressure and other diet-related factors, including micronutrients such as potassium, calcium, and magnesium; macronutrients such as type and amount of dietary fats, particularly polyunsaturated, and protein; and dietary fiber. However, results from individual, randomized, controlled clinical trials testing the effects of these nutrients on blood pressure have been inconsistent and equivocal. On the other hand, both observational and randomized intervention studies have consistently linked vegetarian dietary patterns to lower blood pressure.