What are the health benefits to reading books regularly and frequently?

Many benefits: The benefits are more mental/intellectual than physical. Reading books open up new vistas of intellectual realms, hitherto unexplored for a new appreciation. They can make you more compassionate, understanding by enhancing understanding over all. You may notice that folks who read regularly, are not more civil, but more capable of engaging in a meaningful, intellectual conversation.

Improves the brain: Reading as apposed to auditory or video input challenges your brain to develop pathways to synthesis what you are reading. When you have to produce a mental picture you use more pathways than if the same topic is presented to the brain already laid out. The more you read and the more frequently you read, the more pathways you recruit and the faster and more efficient the brain becomes.