Have you seen those ads for Lumosity, MyBrainTrainer and other “brain gyms,” where you can fork over $15 or more every month to keep your brain youthful? The fear of Alzheimer’s disease and other forms of dementia in later life is as common as the fear of heart attacks and strokes. While some of us head off to the fitness center, others are investing in online brain games. Mental exercises, say “the experts,” can keep you sharp in old age, just as physical exercises keep your body fit through the years.

Time to break out the confetti and rejoice, fellow bookworms! According to research findings reported this past July in Neurology, the medical journal of the American Academy of Neurology, reading books and writing can do as much for you as ready-made mind exercises.

Findings from a six-year research study, supported by the National Institute on Aging and the Illinois Department of Public Health, are remarkable. Memory decline was reduced 32 percent in bookworms who continued reading into old age, compared to engaging in average mental activity. Those who neither read nor wrote frequently experienced a 48 percent decline in memory. “We shouldn’t underestimate the effects of everyday activities, such as reading and writing, on our children, ourselves and our parents or grandparents,” says study author Robert S. Wilson, a neuropsychologist at the Rush University Medical Center in Chicago.

Save your online “brain gym” membership fees and pick up a book instead. Don’t waste another moment. Just like physical exercise, the sooner you start and maintain a regimen, the better you’ll be in the long run. A seven-year study of 2,000 healthy individuals aged 18 to 60 found that mental agility peaks at 22. By 27, mental processes like reasoning, spatial visualization and speed of thought began to decline.

So let your mind take leaps and bounds. Let it take flight. Delight your synapses. Read a book. Then share it with a friend.