I came across a study by Psychoneuroendocrinology that discovered specific molecular changes in the body after meditating. Here is a link to the summary explaining that: “mindfulness meditation can alter neural, behavioral and biochemical processes.”
In this study, researchers compared two different groups. One group had experienced meditators whose role was to meditate throughout the day. The other group had untrained subjects whose role was to enjoy a day of leisure, non-meditative activities.
After 8 hours, researchers compared the two groups. They found that the group of meditators showed a range of genetic and molecular differences (including reduced levels of pro-inflammatory genes, which correlates with faster recovery from stressful situations)!
Here is a link to an article via tunedbody.com, which explains the study in greater detail.