A diet rich in carbohydrates slightly raise the blood pressure as compared to the diet rich in monounsaturated fats. However, the difference is not enough to justify making recommendations to change the carbohydrate and monounsaturated fat content of the diet to control blood pressure. Researchers from the University of Texas Southwestern Medical Center at Dallas reviewed of 10 published studies, that compared high-carbohydrate and high-monounsaturated fat diets to better understand their effect on blood pressure. The results of the mathematical model revealed that the carbohydrate-rich diet led to a significantly higher blood pressure compared with the diet rich in monounsaturated fat. When the analysis was restricted to studies in which the subjects were randomly assigned to one diet and then switch over to the other diet, the blood pressure readings were higher for the carbohydrate-rich diet than the monounsaturated fat diet, but the difference was not statistically significant. The slight increase in blood pressure of subjects in the high-carbohydrate diet may be due to elevated insulin levels. It has been suggested that high insulin levels enhance the activity of the sympathetic nervous system, which increases heart rate, cardiac output, vascular resistance, and sodium retention and thus the blood pressure.
American Journal of Clinical Nutrition,
May 2007