Carbohydrate and fiber recommendations for individuals with diabetes: a quantitative assessment and meta-analysis of the evidence.
The effect of an intended diet, high in cereal fibre, low in fat and sodium was assessed over a 3-month period in 13 type 2 diabetic patients with moderate hypertension (diastolic blood pressure greater than 105 and less than 115 mmHg without antihypertension drug therapy). Eleven patients completed the study and two patients were withdrawn owing to an increase of blood pressure above initial values after 1 month. Using a compliance scoring system by an observer unaware of blood pressure response, patients were divided into those compliant to the dietary regimen (n = 7; group A) and those who were not, and therefore were considered controls (n = 4; group B). Group A demonstrated significant reductions in systolic (190.4 +/- 18 to 166.6 +/- 22.4 mmHg; P less than 0.02) and diastolic blood pressure (113.1 +/- 3.7 to 103.3 +/- 9.1 mmHg; P less than 0.01), weight (78.5 +/- 5.6 to 74.3 +/- 6.8 kg; P less than 0.02), daily urinary sodium excretion (210.3 +/- 79.9 to 120.3 +/- 56.1 mmol; P less than 0.02) and serum LDL levels (P less than 0.02). A reduction in glycosylated haemoglobin of 2.2 per cent was also noted. Three patients achieved a diastolic blood pressure level below 100 mmHg. In contrast, no significant changes occurred in group B. In particular, systolic and diastolic blood pressure (111.0 +/- 2.2 to 110.3 +/- 8.9 mmHg) remained unchanged. We conclude that the modified diet may have a hypotensive effect in diabetic subjects with moderate hypertension. However, the degree of blood pressure reduction suggests that this diet could, at best, only be considered an adjunct to conventional antihypertensive drug therapy.