In 2007, a gold standard double-blind placebo study was presented in the Journal of Human Hypertension, which demonstrated that a chiropractic adjustment, to the upper neck region, lowered blood pressure significantly. In a group of 50 people with early stage hypertension, 25 people had the chiropractic adjustment and 25 did not. None of the patients were allowed to take medication during the eight week study. The patients that had the adjustment saw an average drop of 14mmHG systolic blood pressure and 8mmHg diastolic. Interestingly enough, it would take two blood pressure medications to have the same effect. The researchers also noted that none of the patients getting the adjustments had any adverse reaction to the chiropractic treatment. In my opinion, the coolest part of this study is that they eliminated the patients who had complaints of neck pain. That’s right, they were all asymptomatic patients which means that they had no musculoskeletal complaints anywhere in their bodies. A link to the study is found at the end of this blog.
So why would a chiropractic adjustment decrease blood pressure?
It is the same reason, neurologically, that the adjustment would decrease overall stress in the body. When a spinal segment is subluxated (see subluxation blog for more information), or misaligned causing a restriction in range of motion, it interferes with the neurological message to the brain. The small joints in the spine constantly tell your brain where it is in space and time. Also, movement of the spine actually stimulates your brain. Why do you think toddlers like to move around and get into just about everything? They are learning and their brains are growing. This is also why it is counterproductive to have kids sit all day in classrooms without proper movement. When these joints are not moving, the brain receives stress signals from the body called nociception. Nociceptive signals activate the sympathetic nervous system or “fight or flight” response. It is the same response that would activate if the body was in trouble (ie. Saw a bear). This response is quite healthy short-term; however, it is devastating to the body’s overall health when chronically activated. Now, here’s the big question: If you saw a bear, would your heart rate and blood pressure increase or decrease? Silly question right? Of course your heart would pump like crazy to get blood to the organs which would get you away from the bear or attack it (hence why it is called “fight or flight”).
On the other side, the adjustment, which realigns the spinal joints by putting proper movement into them, not only decreases nociception but clinically increases proprioception. Propioception is the healthy stimulation to the brain which overrides the nociception thus decreases the stress response. Cool right? So every time anybody gets adjusted, it decreases the stress in their bodies meaning that all stress responses in the body will decrease. This would explain why chiropractic care throughout history has been anecdotally known to help stimulate immunity, improve digestive problems, difficulty breathing, reproductive issues, and so on. All of these symptoms or conditions are a reaction of the sympathetic “fight or flight” nervous system. When you turn it off, these symptoms decrease significantly.
It is extremely important to makes sure your spine has optimal health so that your entire body functions without stress. The stress response is not supposed to be used chronically but only in short-term situations to get us out of the stressful environment. Nowadays, with deadlines and rush hour traffic, stress is extremely hard to avoid and that is why it is important to get your regular spinal adjustments, exercise by moving those spinal joints, and keeping your mind at ease through meditation. Regular chiropractic adjustments keep your stress levels down and your body functioning better.