Blood pressure responses in healthy older people to 50 g carbohydrate drinks with differing glycaemic effects.

The aim of the present study was to determine the effects on blood pressure response of 50 g carbohydrate drinks with differing glycaemic effects in ten healthy elderly subjects (age > 65 years; randomized crossover design). Systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure, heart rate and plasma glucose levels were determined following ingestion of equal volumes (379 ml) of water and 50 g carbohydrate drinks with differing reported glycaemic indices (GI) (surrogate marker for glycaemic effect): (1) low-GI: Apple & Cherry Juice; (2) intermediate-GI: Fanta Orange; (3) high-glucose. Glucose (SBP and DBP P < 0.001; MAP P = 0.005) and Fanta Orange (SBP P = 0.005; DBP and MAP P < 0.001) ingestion caused a significant decrease in BP whilst blood pressure increased (SBP P = 0.008; MAP P = 0.005) from baseline following Apple & Cherry Juice ingestion. Water had no significant effect on postprandial blood pressure. Fanta Orange and Apple & Cherry Juice caused similar (P = 0.679) glycaemic effects, which were significantly greater than water, but lower than glucose (P < 0.001). There was no significant correlation between the glycaemic effect of the carbohydrate drinks and there was no change in blood pressure from baseline (SBP r - 0.123, P = 0.509; DBP r - 0.051, P = 0.784; MAP r - 0.069, P = 0.712). Apple & Cherry Juice and Fanta Orange had similar glycaemic effects, but differing effects on blood pressure. Therefore, it is unlikely that the glycaemic effect of a drink can be used to predict the subsequent cardiovascular response.