When I thought more about reading and longevity, it made more sense. When you read a novel or non-fiction book, you have to follow the story and pay attention to details for several hours for a week or more while you read the book. For fiction, you have to understand how characters are related and remember their actions so you can make connections later on in the book. For non-fiction, the author makes a claim, or tries to explain a point, and you have to keep all of the details in your head to understand the main points.
It is interesting that the study does not show the same benefits for short writings, like newspaper and magazine articles. Perhaps that is because these are short and the brain does not have to make connections between lots of information for a long time.
What are your thoughts on reading? Tell us how much you read and what you like to read in the comments below!