It’s a familiar occurrence in yoga class. After a series of postures and movements, participants return to downward dog, where the instructor suggests everyone take a long, slow breath, and exhale with the sound of “HA.” During this long breath, instructors will also encourage students to let go of any negative thoughts.
At first glance, it sounds like fluff, but during moments of doubt, a wave of the relaxation moves throughout the body, and even a brightness of one’s mood. [Editor’s Note: you can always skip the 45-minute yoga class for 10 minutes of meditation if your schedule or body isn’t up to it.] It’s easy to knock yogi wisdom as being rife with a positivity bias, but recent studies have shown that science supports mindful breathing. Generally, we know that inhaling provides oxygen to the lungs and bloodstream while exhaling releases carbon dioxide. But our breaths can do so much more: they can affect our mental states, and subsequently, lead to positive changes in our body like the suppression of genes expressing for inflammation, as well as lower levels of cortisol in our bloodstream.
In a recent study published in Science, researchers may have found an explanation to explain why slow, long breaths typical in mindful meditative activities induce tranquility. The team, led by Kevin Yackle, an assistant researcher specializing in physiology at the University of California, San Francisco, linked the main change to genes that express neurons in the preBötC**,** commonly referred to as the pacemaker for breathing. By eliminating the neurons with specific genetic markers, the researchers found that when they placed mice lacking those neurons in novel, stimulating environments, rather than tweak out and sniff erratically—their version of our anxiety-induced hyperventilation—these mice maintained a sense of calmness. Yackle explained that the neurons they’d wiped out in the preBötCwere communicating with the locus coeruleus, a part of the brain responsible for our states of arousal. Arousal is at the heart of mindful breathing, as recent studies have found anxiety and distress are connected to a number of physiological changes. One notable finding is the connection between stress and the length of telomeres, or a sequence of nucleotides that function as protective “caps” at the end of chromosomes. Shorter telomeres are associated with higher likelihood of diseases such as cancer, as well as risk of death. Telomeres shorten every time a cell divides, and although the enzyme telomerase replenishes the lost nucleotides, other factors can speed up telomere shortening, like, well, stress. “Chronic stress rots the cell's resources to recover and help to protect and maintain the DNA productivity,” says Elissa Epel, a professor of psychiatry at UCSF. She adds that oxidative stress and other stress chemicals like cortisol are notable culprits for telomere shortening. But all is not lost.
In 2014, Linda E. Carlson, a professor of psychiatry at the University of Calgary, led a study published in the journal Cancer. For eight weeks, patients performed Mindfulness-Based Cancer Reduction (which is based on the Mindfulness-Based Stress Reduction, a meditative practice that involves a focused attention to one’s breath and typically leads to a state of relaxation detachment). Cancer patients who practiced MBCR maintained their telomere length, while control patients telomeres shortened over the course of the test. Carlson explains that underlying the MBSR and the focus on one’s breath is a connection to sympathetic and parasympathetic nervous systems. When the sympathetic nervous system stimulates our sense of arousal, the parasympathetic response brings us back to balance, such as decreasing blood pressure and lowering one’s heart rate. Carlson says that over time, our sympathetic nervous system evolved to become triggered by much more than it was initially designed. “The threats we faced were acute events, but now we perceive many things as threatening: fight with your partner, being stuck in traffic, all those things can trigger [the] same response,” says Carlson. “You get cortisol flowing through the bloodstream, rapid breathing, heart pounding, but the threat never goes away. So you don’t actually have balance.” By practicing mindfulness breathing and MBSR, Carlson explains, our breath can create a sense of calmness that can have positive effects on our immune system, our telomeres, and our larger physiology. “When [stress] becomes chronic, you get worn down, your body becomes exhausted,” says Carlson. “Mindfulness teaches you how to get back to the balanced place.”