What is the aim of a movie in which old people drink something to stay young?

There are many informational materials teaching everyone to stay young. The aim is not exactly to reduce their ages but to keep them in the conditions of the youth. As people become aged, they may not be able to do certain things they found easy when they were younger, movies that show them how to continue to have the physical peculiarities of a youth while their age continues to count aims at healthy living. It can be summarized that such movies aims at improving their health standards so they can also enjoy themselves more than when they do not have the required information.