It was odd to go swimming in the presence of so much snow, but the 90+ degree heat begged relief. Needless to say, having just written about the immune-enhancing effects of cold water, I was more than excited to tell everyone what I’d just learned, at least as excited as I was to jump back in the lake.
As I returned to civilization, I got to thinking that I’d left my study of hydrotherapy a little early, and that there was more that I could write on the topic. After all, while I’d discussed the effect of hydrotherapy on the immune system and on the body’s antioxidant enzymes, I’d left out the cardiovascular system.
Naturopaths often recommend contrast hydrotherapy to promote circulation by playing off physiologic responses to hot and cold water. Hot water causes blood vessels to dilate, cold water causes them to contract, and by thus alternating back and forth between hot and cold, you can stimulate circulation. This is frequently employed to encourage healing of chronic injuries, but also edema, a type of swelling that is a common effect of high blood pressure.
But what about high blood pressure itself? Can something as simple as finishing your shower with a spell of cold water be helpful with lowering your blood pressure? I took a quick look.
Well, according to a German study from the early 90’s, contrast hydrotherapy can help certain people with high blood pressure. Determining whether you may be helped by this therapy is best done by a licensed naturopathic doctor, as it’s a fairly specific subset of people who can benefit from this treatment. A Czech study done on high blood pressure and cold water therapy was a bit more ambivalent, indicating that diastolic blood pressure (the lower number) was decreased mildly by regular hydrotherapy. Taken together, these indicate some benefit from cold water therapy under certain conditions and for certain patients. As always, talk to your doc when considering this treatment.
In my searches, I found another German study which showed that home-based hydrotherapy produces significant benefits in both quality of life and symptoms for patients with chronic heart failure (CHF). While this is not high blood pressure per se, it can develop because of high blood pressure that goes untreated for long periods of time.
Not yet satisfied, I kept looking primarily to see if I could find perhaps another, similar treatment that was effective against hypertension.
Turns out that the humble sauna, a fixture of Scandanavian countries for centuries, improves high blood pressure (1, 2) and chronic heart failure (1, 2). This alone is reason enough for patients with hypertension to visit the sauna regularly. Additionally, and perhaps more importantly, regular sauna use improves endothelial vascular function (1, 2). It’s a rare lay person that knows why this is important, so here’s a brief, straightforward explanation of why endothelial vascular function matters: endothelial dysfunction contributes to atherosclerosis, which in turn contributes to coronary vascular disease, which in turn causes myocardial ischemia, which if it gets bad enough becomes a myocardial infarction, commonly called a heart attack. So regular sauna use may to prevent heart attacks – seems like a good enough reason to take a 15 minute session at the gym, doesn’t it? As an additional note, saunas of reasonable temperature, enjoyed for a moderate time are perfectly safe – the old notion of saunas provoking stroke or heart attacks isn’t quite accurate.
So there you have it. Saunas improve a number of cardiovascular diseases, cold water activates the immune and antioxidant defense systems. Anyone for a sauna followed by a quick plunge in the snow?