Effect of Functional Bread Rich in Potassium, γ-Aminobutyric Acid and Angiotensin-Converting Enzyme Inhibitors on Blood Pressure, Glucose Metabolism and Endothelial Function

Because it has been suggested that food rich in g-aminobutyric acid (GABA) or angiotensin-converting enzyme inhibitor (ACEI) peptides have beneficial effects on blood pressure (BP) and other cardiovascular risk factors, we tested the effects of low-sodium bread, but rich in potassium, GABA, and ACEI peptides on 24-hour BP, glucose metabolism, and endothelial function. A randomized, double-blind, crossover trial was conducted in 30 patients with pre or mild-to-moderate hypertension, comparing three 4week nutritional interventions separated by 2-week washout periods. Patients were randomly assigned to consume 120 g/day of 1 of the 3 types of bread for each nutritional intervention: conventional wheat lonso, MSc, Anton do, MD, vadó, MD, PhD greater beneficial effects on 24-hour BP, endothelial function, or glucose metabolism were demonstrated after the consumption of LSBþG in a population with pre or mild-to-moderate hypertension. Further studies are warranted to clarify the effect of GABA on BP, preferably using a specific design for noninferiority trials and ambulatory BP monitoring as a measure of BP. This study was registered at Current Controlled Trials as ISRCTN31436822 (Medicine 94(46):e1807) Abbreviations: ABPM = ambulatory blood pressure monitoring, ACEI = angiotensin-converting enzyme inhibitory peptides, AI75 = augmentation index adjusted to 75 beats/minute, AIx = arterial stiffness, BP = blood pressure, CB = conventional bread, cIMT = carotid intima-media thickness, CVD = cardiovascular disease, GABA = g-aminobutyric acid, HPLC = high-performance liquid chromatography, LSB = low-sodium wheat bread, LSBþG = lowsodium wheat bread rich in GABA and ACEI peptides, maxIMT = maximum intima-media thickness, MedDiet = Mediterranean diet, mIMT = mean intima-media thickness, PAT = peripheral artery tonometry, RIA = radioimmunoassay, saRHI = small artery reactive