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,” Dr. David Anderson, who heads research into behavior and hypertension at the NIH’s National Institute on Aging, told the Associated Press.
High blood pressure (hypertension) is one of the leading causes of death in Canada, affecting about one of every five adults.
High 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-treatening 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.
If Anderson’s theory is right, it would offer another explanation for why hypertension is what he calls “a disease of civilization and a sedentary lifestyle.”
Meanwhile, health authorities recommend lowering blood pressure by making changes in your lifestyle including:
• Eat healthy foods (low in fat and salt)
• Quit smoking
• Keep a healthy body weight
• Get regular exercise
• Cut down on alcohol
Risk factors for “primary” or “essential” hypertension*:
• Age: Blood pressure tends to rise with age. About half of people over the age of 65 have high blood pressure.
• Ethnicity: The incidence of high blood pressure is higher among members of some ethnic groups, such as South Asians, First Nations, Aboriginal Peoples or Inuit, and Black Canadians.
• Family history: If one of your parents has high blood pressure, you have a 1 in 5 chance of developing the condition. If both of your parents have high blood pressure, your risk is 1 in 3.
• Obesity: Excessive weight is a risk factor — especially if weight is stored around the abdomen.
• Diabetes: People with diabetes are at increased risk for high blood pressure.
• Stress: Repeated exposure to stress may raise blood pressure levels or contribute to unhealthy lifestyle choices.
• Excessive alcohol consumption: Alcohol increases blood pressure.
• Cigarette Smoking: Smoking may cause high blood pressure in certain individuals.
*Source: The Heart and Stroke Foundation
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