Effect of oat β-glucan in managing blood pressure: a randomized cross-over pilot trial

Hypertension affects over 1.2 billion adults worldwide. While numerous pharmacological treatments are available for managing hypertension, dietary approaches may also offer beneficial alternatives or complementary strategies. High molecular weight (HMW) β-glucan, a fibre found in oats, may be responsible for reductions in systolic blood pressure. This pilot trial investigated the efficacy of HMW oat β-glucan in reducing systolic and diastolic blood pressure in individuals with mild hypertension. Additionally, changes in heart rate, body weight, waist circumference, and dietary intake, including protein, carbohydrates, fat, and fibre were assessed. This study was conducted virtually during the COVID-19 pandemic. The trial followed a randomized, double-blinded, cross-over design. During the treatment period, participants were provided breakfast cookies made from oats containing 4 g/day of HMW oat β-glucan. During the control period, participants received breakfast cookies made primarily from wheat, which does not contain a significant amount of β-glucan (0.12 g/day). Twenty-one people completed the trial. Consumption of oat β-glucan breakfast cookies for 4 weeks did not reduce systolic blood pressure (132.71 ± 1.92 vs. 132.9 ± 1.92, <i>p</i> = 0.95) or diastolic blood pressure (82.86 ± 1.43 vs. 82.38 ± 1.43, <i>p</i> = 0.98) compared to control. Waist circumference (<i>p</i> = 0.67), weight (<i>p</i> = 0.79), heart rate (<i>p</i> = 0.73), and dietary intake (protein (<i>p</i> = 29), carbohydrate (<i>p</i> = 0.45), fat (<i>p</i> = 12), and fibre (<i>p</i> = 0.64)) were unchanged. Our results indicate that oat β-glucan consumption does not affect systolic or diastolic blood pressure compared to a wheat-based control in middle age and older adults with mild hypertension.