American Chemical Society Symposia Series No. 993, Functional Food and Health.  August 2008. Pp. 446-453.
Chapter 39: The effects of Morinda citrifolia L. noni on high blood pressure: a mechanistic investigation and case study. 
Palu AK, Santiago RA, West BJ, Kaluhiokalani N, Jensen J.

Tahitian Noni Juice inhibited angiotensin converting enzymes in vitro.  During an open-label clinical trial, moderately hypertensive adults consumed 2 fluid ounces of Tahitian Noni Juice twice a day, for 1 month. By the end of the trial, average blood pressures of 144/83 had decreased to 132/76 mmHg. (original abstract available at