I drink two cups of coffee in the morning and one in the afternoon, followed by a large mug of green tea in the afternoon everyday. I do that because I enjoy drinking these two beverages. If they are beneficial to my health that is a bonus.
Risk of death from any cause was 63% less in individuals drinking 4 cups or more of green tea, plus 2 or more cups of coffee per day according to a study published tracking 4900 participants in Japan.
Just a note. This study was on diabetics only. Folks with diabetes have a shorter life expectancy and coffee and green tea might help them reach an age close to the life expectancy of the general population.