The author of the book "The Main Factor of Health," academician of the International Academy of Sciences for Ecology, Human Safety and Nature Druzyak Nikolai Grigorievich in a popular science form talks about a new look at the problem of human health and longevity. We can confidently say that humanity's dream of extending life has already come true with the help of its method, which preserves youth and health. The way to solve this problem turned out to be quite simple and, most importantly, not requiring large financial costs and physical efforts when applying it.