There have been a number of clinical studies focused on the effectiveness of acupuncture to reduce blood pressure in essential hypertension. In 1975, Tam et al. found that acupuncture produced a significant reduction in systolic and diastolic blood pressure in 24 out of 28 patients with essential hypertension (Tam et al., 1975). Shortly after 30 minutes of acupuncture, both systolic and diastolic blood pressure were lowered by 10–20 mmHg in 50 patients with essential hypertension (Chiu et al., 1997), suggesting an immediate post-acupuncture effect.
After 6 week-treatment, acupuncture, but not sham acupuncture, significantly lowered mean 24-hr ambulatory blood pressures in 144 outpatients with un-complicated arterial hypertension (Flachskampf et al., 2007). Others also showed that acupuncture performed once weekly for 8 weeks, significantly reduced blood pressure. This beneficial effect appears to persist for a prolonged period of time (Zhou et al. 2012).
Acupuncture reduces blood pressure through modulation of the endocrine system, including decreases in plasma renin, aldosterone, and angiotensin II activity. Glutamate, acetylcholine, opioids, GABA, serotonin, nitric oxide (NO), and endocannabinoids in the brain all appear to participate in mediating anti-hypertensive response of acupuncture (Zhou et al. 2012)