Meditation alters the activity of genes linked to stress and depression, a study has shown.

Researchers examined evidence for mind-body interventions (MBIs) such as meditation, yoga and Tai Chi, affecting DNA.

Data from 18 studies involving 846 participants revealed a pattern of molecular changes in the body that benefit mental and physical health.

The key was nothing to do with unblocking Chakras but a gene-regulating stress molecule called nuclear factor kappa B (NF-kB).

Under its influence, certain genes switch on a "fight or flight" response to stress which over time can increase the risk of cancer, accelerated ageing, and mental disorders such as depression.

People who practice meditation and other MBIs lower their production of kappa B and the stress effects it triggers, the scientists found.

Lead investigator Ivana Buric, from the Brain, Belief and Behaviour Laboratory at the University of Coventry, 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.

"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."

The research is published in the journal Frontiers in Immunology.