Purple Sweet Potato Aqueous Extract Lowers Blood Pressure and Prevents Oxidative Stress in Hypertensive Elderly Patients at Nyuhkuning Village, Mas, Ubud, Bali

Purple sweet potato tubers found in Bali are rich in anthocyanins and has been studied as an antioxidant in experimental animals. Aqueous extract of purple sweet potato tubers has been shown to lower blood pressure through increased expression of endothelial nitric oxide synthase (eNOS) in hypertensive rats. Research on the antihypertensive and antioxidative effects of aqueous extract of purple sweet potato tubers in hypertensive patients has not been done. The purpose of this study was to prove that the aqueous extract of purple sweet potato tubers could lower blood pressure and prevent oxidative stress in hypertensive patients especially in the elderly ones. This study was a limited clinical trial with one group pre- and post-test design, involving the elderly population in Nyuhkuning Village, Mas, Ubud, Bali as subjects of study. Seventeen subjects were included in this study with baseline characteristics such as 60-69 years of age, blood pressure above 140/95 mmHg, and does not suffer from certain diseases. After being given aqueous extract of purple sweet potato for one month, they showed a decrease in systolic and diastolic blood pressure significantly (p < 0.05), a decrease in MDA level accompanied by an increase in blood superoxide dismutase (SOD) level significantly (p < 0.05). From these results, it can be concluded that the aqueous extract of purple sweet potato tuber can lower blood pressure and prevent oxidative stress in hypertensive elderly patient.