New studies assessing the effects of high-carbohydrate versus high-monounsaturated fat diets have found that patients with type 2 diabetes experienced modest increases in blood pressure after 14 weeks on a a high-carbohydrate diet compared to a high-monounsaturated fat diet.
One diet provided 55% of calories from carbohydrates, 30% from fat, with only 10% from monounsaturated fats. The other diet consisted of 40% carbohydrates, 45% fat, and 25% monounsaturated fats.
In the study, 42 patients with type 2 diabetes each followed both diets for 6 weeks, separated by a 1-week break. Afterwards, some patients continued on one of the diets for an additional 8 weeks—8 on the high-monounsaturated fat diet and 13 on the high-carbohydrate diet.
After the initial 6 weeks, no significant differences were found between the two diets in systolic or diastolic blood pressure or heart rate.
However, after the 8-week extension, those on the high-carbohydrate diet showed a 7-point increase in diastolic blood pressure, a 6-point increase in systolic blood pressure, and an increase in heart rate by 7 to 8 beats per minute compared to the end of the initial phases.
Conversely, patients continuing the high-monounsaturated fat diet experienced a significant decrease in heart rate, with systolic and diastolic blood pressure readings 3 to 4 points lower after 14 weeks, although these blood pressure changes were not statistically significant.
Overall, the findings suggest that a diet higher in monounsaturated fats may help maintain better blood pressure and heart rate levels in people with type 2 diabetes compared to a high-carbohydrate diet.