Carbohydrate-rich diets have a worse effect on blood pressure than diets big on mono-unsaturated fats
Carbohydrate-rich diets have a worse effect on blood pressure than diets big on mono-unsaturated fats
KEY POINTS:
Carbohydrate-rich diets are associated with slightly higher blood pressure than diets rich in mono-unsaturated fats, findings in the American Journal of Clinical Nutrition show.
However, Meena Shah and colleagues from the University of Texas Southwestern Medical Centre at Dallas found the difference is not enough to justify makingrecommendations to change the carbohydrate and mono-unsaturated fat content of the diets to control blood pressure.
The researchers conducted a review of 10 published studies that compared high-carbohydrate diets and diets high in mono-unsaturated fat to better understand their effects on blood pressure.
The results of the authors' mathematical model showed carbohydrate-rich diets led to a significantly higher blood pressure compared with diets rich in mono-unsaturated fat.
When the analysis was restricted to studies in which the subjects were randomly assigned to one diet and then switched over to the other diet, the blood pressure readings were higher for the carbohydrate-rich diets than the mono-unsaturated fat diets, but the difference was not statistically significant.
The slight increase in blood pressure of subjects in the high-carbohydrate diet may be caused by elevated insulin levels or "hyperinsulinemia".
It has been suggested hyperinsulinemia enhances the activity of the sympathetic nervous system "which increases heart rate, cardiac output, vascular resistance, and sodium retention and thus blood pressure".
