A new study shows that yoga and other mind–body interventions (such as meditation or tai chi) can positively affect molecular reactions in our DNA. Far from simply relaxing those who practice it, yoga makes them healthier in observable ways. 
The study was undertaken by the University of Coventry in the UK and the University of Radboud in the Netherlands. The authors reviewed more than a decade’s worth of studies that examined how mind–body interventions affected gene behavior.
The results confirmed what many already believed about yoga.
The simple exercise can yield concrete results, namely less inflammation throughout the body. 
One of the study’s lead authors, Ivana Buric, said “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 realise is that these benefits begin at a molecular level and can change the way our genetic code goes about its business.”
The mechanism by which this works is fairly complicated but well studied.
Our sympathetic nervous systems increase production of a molecule called nuclear factor kappa B (NF-kB) when we are in stressful situations. NF-kB makes genes produce inflammation-inducing proteins called cytokines. These proteins help trigger a fight-or-flight response, which is good for short-term survival. But in the long run, this response can cause cancer, accelerated aging, and depression.
Practicing mind–body interventions can reverse these effects.
Calming the body through yoga, meditation, or tai chi decreases the production of NF-kB and thus cytokines. 
Buric further explains, “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 wellbeing.” When you stop to think about it, our fight-or-flight responses are not as necessary in modern times as they were in the past. When the world was wilder, with large predators, we had much more of a need to jump-start our bodies to respond to dangers. 
Now, the gene response causes health problems more than it saves us from dangerous situations. Fortunately, reducing these inflammation-causing chemicals may be as simple as enrolling in a yoga class or setting aside an hour a night for meditation.
Scientists still have a long way to go to more fully understand the positive benefits of mind–body interventions.
For example, there is more to learn about which types of yoga or meditation do the most to reduce inflammation. 
Buric summed up the situation by saying, “More needs to be done to understand these effects in greater depth, for example how they compare with other healthy interventions like exercise or nutrition. But this is an important foundation to build on to help future researchers explore the benefits of increasingly popular mind–body activities.”
