In a new study, researchers have uncovered a molecular explanation for the stress-relieving effects of such practices. Study leader Ivana Buric, of the Centre for Psychology at Coventry University in the United Kingdom, and colleagues found that mind-body interventions (MBIs) “reverse” changes in DNA that cause stress. For their study, the researchers looked at whether MBIs influence gene expression, the process by which genes create proteins and other molecules that affect cellular function. From their analysis, the researchers found that people who practice MBIs experience reduced production of a molecule called nuclear factor kappa B (NF-kB), which is known to regulate gene expression. The researchers explain that stressful events trigger activity in the sympathetic nervous system (SNS), which is responsible for the “fight-or-flight” response. This SNS activity leads to the production of NF-kB, which produces molecules called cytokines that promote cellular inflammation. If this molecular reaction is persistent, it can lead to serious physical and mental health problems, such as depression and cancer. The study suggests that MBIs, however, lower the production of NF-kB and cytokines. This not only helps to alleviate stress, but it also helps to stave off the associated health conditions. “Millions of people around the world already enjoy the health benefits of mind-body interventions like yoga or meditation, but what they perhaps don’t realize is that these benefits begin at a molecular level and can change the way our genetic code goes about its business,” says Buric. “These activities are leaving what we call a molecular signature in our cells, which reverses the effect that stress or anxiety would have on the body by changing how our genes are expressed. Put simply, MBIs cause the brain to steer our DNA processes along a path which improves our well-being.” The team says that future studies should explore how the molecular effects of MBIs on stress compare with other interventions, such as exercise and diet. “But this is an important foundation to build on to help future researchers explore the benefits of increasingly popular mind-body activities,” Buric concludes. Separately, a new study has found that the treatment can be more harmful than helpful if cardiac stem cells are involved. Researchers found that using patients’ own cardiac stem cells to repair damaged heart tissue may not only be ineffective, but that the stem cells may also develop inflammatory properties that cause further heart damage. Study leader Prof Jonathan Leor, of the Sackler Faculty of Medicine and Sheba Medical Center at Tel Aviv University in Israel, and colleagues recently reported their findings in the journal Circulation. Prof Leor and colleagues came to their findings by isolating stem cells derived from the cardiac tissue of mice that had left ventricular dysfunction caused by a heart attack. The team then injected the stem cells back into the hearts of the mice and assessed how they affected heart remodelling and function, compared with a saline solution. Instead of repairing the rodents’ damaged heart tissue, the researchers found that the transplanted stem cells developed inflammatory properties, which may increase heart damage.”We found that, contrary to popular belief, tissue stem cells derived from sick hearts do not contribute to heart healing after injury,” explained Prof Leor. “Furthermore, we found that these cells are affected by the inflammatory environment and develop inflammatory properties. The affected stem cells may even exacerbate damage to the already diseased heart muscle.” An increasing number of end-stage heart failure patients are turning to stem cell therapy as a “last resort,” but the researchers believe that the treatment should be approached with caution. “Our findings suggest that stem cells, like any drug, can have adverse effects. We concluded that stem cells used in cardiac therapy should be drawn from healthy donors or be better genetically engineered for the patient.”