The Journal of Upper Cervical Chiropractic Research published a study on April 24, 2012 documenting the positive effects chiropractic care has on normalizing blood pressure. This study was unique in that it looked at the effect of chiropractic on a full range of blood pressure situations and not just on the effect chiropractic has on high blood pressure.
Several previous studies have documented that chiropractic care has the effect of lowering blood pressure significantly on test subjects. The author of this study reviewed the prior studies noting that each of them showed significant improvement in patients with hypertension. One such study was done at the Hypertension Center at the University of Chicago Medical Center and published in the March 2, 2007 issue of the Journal of Human Hypertension. The study's leader, George Bakris, MD, commented, "This procedure (chiropractic) has the effect of not one, but two blood-pressure medications given in combination. And it seems to be adverse-event free. We saw no side effects and no problems."
This study looked at 42 individuals with a variety of blood pressure readings in order to compare the impact chiropractic care had on the group as a whole. In this group, there were 12 subjects with a lower blood pressure than normal, considered "hypotensive", 12 people with blood pressure in a normal range called "normotensives", 10 with slightly high blood pressure reading considered, "pre-hypertensive," and 8 who had blood pressure readings high enough to clearly fall into the categories of being stage 1 or stage 2 hypertensive.
Specific chiropractic care for correction of subluxation at the "Atlas" (top bone in the neck) was given to the group. This study reviewed data from three groups consisting of Group 1- hypotensives, Group 2- normotensives and Group 3- hypertensive, which combined the pre-hypertensive with the stage one and stage two hypertensive group.
The results for the hypotensive group with lower blood pressure showed that their average blood pressure increased to within a normal range. The study recorded that the average pre-chiropractic systolic pressure was 84.33 mmHg compared to the average post-chiropractic systolic pressure which was 98.17 mmHg. Similar improvements were seen in the diastolic pressures going from 64.83 mmHg to 73.67 mmHg after chiropractic care was initiated.
The group with normal blood pressure reading showed a slight decrease in both their systolic and diastolic reading after chiropractic care.
The biggest changes were in the groups of hypertensive and pre-hypertensive people where the systolic pressure group average was 152.61 mmHg before chiropractic, and the average after the introduction of chiropractic care fell to 132.39 mmHg. The diastolic values for this group for pre and post chiropractic care also showed improvement going from 83.83 mmHg to 77.00 mmHg.
In his conclusion, the author wrote, "These findings suggest realignment of the atlas does not simply lower ABP (arterial blood pressure) but may also be part of a systemic homeostatic mechanism not yet completely understood. The same adjustment that decreased hypertensive ABP measurements also increased hypotensive ABP measurements to more normal levels."