The benefits of meditation and mindfulness are well documented. In fact, there are even entire organizations devoted to research around mindfulness, for example: The American Mindfulness Research Association: https://goamra.org.
Just as we know there are benefits to a healthy diet and fitness; the research shows that meditation and mindfulness practice produce real, measurable results. Meditation literally changes your brain! It can be helpful to understand the benefits because the practice takes time and discipline; knowing that the time it takes to practice meditation is worthwhile and beneficial can be a great motivator to get started and stick with it.
Here is a quick slide show done by Huffington Post citing 9 quick facts from mindfulness scientific research:
Here are two great videos about the scientific benefits of mindfulness:
READINGS
-Here is a great, brief overview on the benefits of mindfulness practice by Greg Flaxman and Lisa Flook, Ph.D. at UCLA.