Friday, October 7, 2011

More On High Blood Pressure

Cardiovascular disease is one of my favorite topics, in no small part because of the important role that diet and lifestyle play in preventing and managing it. Admittedly, not all cardiovascular disease is caused by diet and lifestyle, but the vast majority, especially in contemporary America, can be traced to these two factors.

Today, I’m writing about high blood pressure (called hypertension by us medical professionals), because I regularly see patients looking for help bringing down their blood pressure, and have noted some misconceptions. And as always, I believe in putting knowledge into the hands of patients, especially high quality, peer-reviewed knowledge. There’s a lot of info out there on the Internet anyway, not always of reliable quality, so it’s important to me to make good quality material available as well.

Here’s an important caveat before we launch into the discussion: Maintaining your health isn’t easy and you shouldn’t go it alone. It’s important to have the knowledge you need to take proactive steps towards health, but it’s also important to recognize the benefit of working with a trained professional who can help you set and reach goals, monitor your progress, make modifications when needed, and otherwise help guide you.

So here’s the misconception: A low-salt diet is the most important dietary change you can make to help reduce your blood pressure. There is some truth behind this, and indeed a low salt diet can help to lower your blood pressure. However, according to the JNC 7, the most recent report on hypertension published by the National Institutes of Health, that effect is modest at best. A reduced salt diet will indeed help reduce your blood pressure, and excessive salt consumption isn’t particularly healthy, but the JNC 7 is clear – the expected effect is a drop of only 8 points, possibly as few as 2 points, and for most people with high blood pressure, that isn’t enough to take care of things.

Regular, moderate aerobic exercise can also be expected to help lower blood pressure. Here too the effects were moderate but noteworthy, bringing blood pressure down about 5-10 points. While this effect is moderate, regular exercise has a lot of additional benefits, so I am unreserved about my advice regarding exercise. We’ll return to exercise in a moment.

Despite mild to moderate effects from these two recommendations, the JNC 7 is very clear that there are diet and lifestyle changes that are effective and can produce stronger therapeutic effects. While salt restriction alone results in only mild decreases in blood pressure, the DASH diet, a more comprehensive dietary plan, can produce drops in blood pressure of up to 14 points. The DASH diet does include recommendations for salt restriction, but also includes broader dietary recommendations that help to boost its blood pressure lowering effects. A broader, more complete description of the DASH diet is available from the NIH, but the basic premise is this: low amounts of saturated fats, low amounts of refined carbohydrates (sugars), plenty of vegetables, fruits and whole grains. In my experience, most patients with hypertension need to cut their blood pressure by 15-20 points, so this diet plan is going to be an important addition to anyone’s treatment plan.

Back to exercise. Exercise alone, in an otherwise healthy person, would have mild to moderate effects on someone’s blood pressure. However, exercise as a means to an end can have more significant effects. The JNC 7 report clearly and unequivocably states that the most significant reduction in blood pressure comes from maintenance of healthy weight, going so far as to say that reductions of up to 20 points can be achieved from every 10 kg (22 pounds) lost. Healthy weight is defined as having a BMI between 18.5 and 24.9 – calculating BMI involves some tricky math, so here’s a neat calculator to use. For folks with hypertension, it’s an intervention like this that will help bring numbers down the most, and with a drop large enough to help restore normal blood pressure, and to be worth the effort.

Let me repeat the caveat again: Work with a doctor when lowering your blood pressure. Not only can a doctor help setting goals and monitoring progress, but as you can see, reducing blood pressure through diet and lifestyle changes is effective but can be challenging – weight loss in particular is frequently no easy feat. A doc can help determine the best methods to pursue, and help you implement plans. While naturopathic physicians are more than happy to spend the time with you to work out these plans, don’t rule out MDs either – after all, these recommendations were developed by a group of high-ranking MDs. And as always, these are prescriptions for healthy living, not just high blood pressure.