Scientists believe that challenging the body can benefit the brain. Dr Michael Mosley learns how meditation can help fight dementia and how people can sharpen their minds by being more like children.

The senses, with age, begin to wane. In this episode Michael Mosley discovers how we can keep our senses: smell, hearing and vision sharp, when we begin to age.

What is the secret to looking good and how can we keep looking good over the years? It is believed that around 60 percent of Americans use some anti-aging product, but what control do we have over our appearance in old age?

For most people, the risk of getting sick increases with age. Dr. Mosley wants to find out how we've become so much better at fighting infection, and he's looking for the secrets to keeping our bodies healthy on the inside, starting with the immune system.

Throughout human history, aging has been our inevitable fate, but is it still so? As extraordinary as it may seem, there are scientists who believe that it is possible not only to slow down, but even to reverse this aging process.