New study findings presented at the American Society of Hypertension's annual meeting say it may be a good idea to take some deep breaths next time you're feeling stressed.
The recent research, conducted at the Kaleida Health-Millard Fillmore Hospital in Buffalo, New York, reinforces previous findings that suggest Pranayama may help lower blood pressure.
Researchers took 12 people between the ages of 22 and 55 with normal blood pressure and subjected them to mental stress for five minutes by asking them to perform a frustrating mathematical task. Then they compared the use of controlled breathing—inhaling and exhaling at a rhythmic pace—with listening to classical music, nature sounds, or no intervention, to measure how long it takes for blood pressure levels to return to normal.
Results showed that classical music made systolic blood pressure (SBP)—the top number that reflects blood pressure when the heart contracts—drop to pre-stressed levels after an average time of 2.9 minutes, nature sounds worked in 3. minutes, and doing nothing normalized SBP after 3.7 minutes, whereas deep breathing returned SBP to normal after just 2.7 minutes.
Diastolic blood pressure (DBP) was slower to return to normal, but after four minutes, readings had dropped by 11.2 percent with yogic breathing, compared to 2.7 percent for the group doing nothing. This suggests that DBP would return to normal levels more quickly with yogic breathing.
Lead researcher B. H. Sung, an associate professor of medicine at the State University of New York at Buffalo, believes that even hypertensive patients would have similar results, although the higher the blood pressure, the more time it would take for the pressure to come down.
B. H. Sung and her coresearchers speculate yogic breathing may work by relaxing muscles that constrict blood vessels and changing the signals sent to the brain that announce stress to the body. Sung believes the technique may prove an effective complementary form of therapy to medication and lifestyle changes for hypertensives.
As for those with normal blood pressure, adds Sung, "Luckily, our findings suggest that something as simple as deep breathing, even for those who've never been exposed to yoga before, can help to reduce the effects of constant daily stress, including rise in blood pressure."
In the study, researchers had the participants close their eyes, and then instructed them to pay attention to each inhalation and exhalation.
Sung says the rhythmic breathing helped relax the individuals. "This makes sense if we figure that when we are going about our day, we don't think about breathing, with the consequence of holding our breath at times and engaging in shallow breathing."
Mental or physical stress basically results in faster breathing, a more rapid heart rate, and constriction of blood vessels, which combine to make the heart work harder and blood pressure rise.
"Relaxation is believed to cause the hypothalamus to respond, which results in a decrease in sympathetic nervous system arousal," says M. Mala Cunningham, Ph.D., creator of Cardiac Yoga, a patented system of yoga for heart disease patients. "When the sympathetic nervous system response (which prepares the body for emergencies) is decreased and the parasympathetic response (which slows the body down) is activated, it results in decreased muscle tension, blood pressure, and respiration."