In the 21st century, doctors pride themselves on practicing evidence-based medicine. Recent studies of treatment for hypertension suggest, though, that practice is sometimes influenced by belief and habit as much as by evidence.

Prescribing drugs for patients whose blood pressure is 160/100 or higher is well-supported by research that shows such treatment saves lives. What is less clear, however, is whether patients with milder hypertension actually benefit from drug treatment.

A systematic review of high-quality clinical trials by the independent Cochrane Collaboration revealed that antihypertensive drugs have not been shown to benefit patients with mild hypertension and no pre-existing cardiovascular disease (Cochrane Database of Systematic Reviews, Nov. 14, 2012).

Mild hypertension was defined with the upper number (systolic blood pressure) running between 140 and 159 and the lower number (diastolic blood pressure) between 90 and 99. Most physicians in the U.S. have been trained to treat patients with blood pressure in this range using medications.

British doctors, on the other hand, tend to be more conservative. A recent commentary by a London physician, “Waste and Harm in the Treatment of Mild Hypertension,” pointed out that treating such patients does not offer them any benefit but does pose risks (JAMA Internal Medicine online, May 13, 2013).

The author underscores the influence of the pharmaceutical industry on existing treatment guidelines. Lowering the threshold for blood pressure treatment has been called “disease creep.” It created 13 million new “hypertensive” patients in the U.S. overnight.

The physician who pioneered hypertension screening, Dr. Julian Tudor Hart, responded to the Cochrane analysis, “Why has it taken more than 30 years to reach this conclusion, when it was already evident from any careful and critical reading of the trials claimed originally to justify intervention in the diastolic range 90-100 mm Hg?”

People’s Pharmacy readers know that our first recommendations for lowering mildly elevated blood pressure usually are the nondrug approaches doctors refer to as therapeutic lifestyle changes (TLC). These include diet, exercise, relaxation therapies, smoking cessation, alcohol moderation and certain mineral supplements.

Following through on such lifestyle interventions is challenging, but it can lower blood pressure nearly as well as medication. TLCs do not trigger side effects and often have additional health benefits. Both the Mediterranean diet and DASH (Dietary Approaches to Stop Hypertension) have strong evidence to support their positive influence on cardiovascular outcomes.

People often complain about dizziness or sexual side effects with blood pressure medicine. ACE inhibitors like lisinopril and ramipril can lead to persistent coughing that can be incredibly disruptive.

One reader reported: “My doctor told me that the cough that developed a month after taking lisinopril could not be due to the medicine. He said it would have happened anyway. I was given an inhaler for asthma. After using it to no avail, I insisted that we change the BP medicine, and the cough disappeared.”

To practice evidence-based medicine, doctors need to keep up with the research and follow their oath to “First, do no harm.”

In their column, Joe and Teresa Graedon answer letters from readers. Write to them via their website: