Research suggests that the way we breathe may hold a key to how the body regulates blood pressure.
When is the last time you thought about how you breathe? Take a slow, deep breath, and then exhale slowly. Do it again. Try to take no more than 10 breaths in a minute.
Research suggests that the way we breathe may hold a key to how the body regulates blood pressure. And while it has been long known that deep, slow breathing enhances relaxation, it may also help the body break down the salt we eat.
“If you sit there under-breathing all day and you have a high salt intake, your kidneys may be less effective at getting rid of that salt than if you’re out hiking in the woods,” says Dr. David Anderson, who heads research into behavior and hypertension at the NIH’s National Institute on Aging.
High blood pressure (hypertension) is one of the leading causes of death in Canada, affecting about one of every five adults.
igh blood pressure can increase risk for strokes, heart attacks, and heart and kidney failure. It is also related to dementia and sexual problems. While the incidence of this disease increases with age, problems can be prevented if high blood pressure is properly treated and controlled.
“The life-threatening health consequences of elevated blood pressure make it clear that every patient needs to reduce their blood pressure to below 140/90mmHg,” said Dr. Robert Petrella, president of Blood Pressure Canada.
Blood pressure allows blood to flow and deliver oxygen and food to the body. While anyone can get high blood pressure, people who are overweight and inactive, and eat too much salt are at higher risk. In fact, health experts say that losing weight, increasing physical activity and cutting back on sodium are the most effective lifestyle changes people can make to lower blood pressure. Even so, most hypertension patients need medications, too.
While the risk factors are known, scientists don’t fully understand the root causes of hypertension. Earlier clinical trials on a nonprescription medical device called RESPeRATE showed that slow, paced breathing had a positive effect on lowering blood pressure. Dr. Anderson is now using the machine to test his theory on the effects of breathing on kidney function.
“Slow, deep breathing does relax and dilate blood vessels temporarily, but that’s not enough to explain a lasting drop in blood pressure,” says Anderson.
Dr. Anderson’s theory, which he will test in a laboratory in Baltimore, Maryland, is that when under chronic stress, people tend to take shallow breaths and unconsciously hold them, what Anderson calls inhibitory breathing. Holding a breath diverts more blood to the brain to increase alertness, but it wrecks havoc on the blood’s chemical balance. More acidic blood in turn makes the kidneys less efficient at pumping out sodium.
In animals, Anderson’s experiments have shown that inhibitory breathing delays salt excretion enough to raise blood pressure. Now he’s testing whether better breathing helps people reverse that effect.
“They may be changing their blood gases and the way their kidneys are regulating salt,” he says.