Clinical Effects of Brown Seaweed, Undaria pinnatifida (wakame), on Blood Pressure in Hypertensive Subjects

This was conducted to examine the effects of brown seaweed (wakame) on blood pressure and serum biochemical parameters in hypertensive subjects. Of the 37 elderly out-patients with hypertension who started the study, 36 of them completed it. This study was a randomly assigned, case-controlled one. Nineteen patients received a daily dose of 5g of dried wakame powder packed in 12 capsules. Eighteen gender-matched subjects with age difference±2 years, and starting time of participation within±2 weeks, were selected as the control group. Patients visited the clinic every 4 weeks. The observation period was 8 weeks. In the wakame group, the average amount of wakame ingested was 3.3g. The systolic blood pressure (SBP) in this group dropped 13mmHg below the baseline (p<0.01) after 4 weeks, and 8mmHg (p<0.05) after 8 weeks. The diastolic blood pressure (DBP) decreased by 9mmHg (p<0.01) after 4 weeks and by 8mmHg (p<0.05) after 8 weeks. In the control group, no significant changes were seen in either SBP or DBP. However, the differences in reduction in SBP and DBP were significant between the wakame and control groups. Regarding clinical chemistry data, hypercholesterolemia in the wakame group decreased by 8% after 4 weeks. No other abnormal changes were observed in either group. We conclude that wakame has beneficial effects as a supplemental regimen in the treatment of hypertension.