This research was carried out over 5 years with some 500 elderly couples. Following the experiment scientists showed that couples who looked out for each other and cared for each other, fell ill half as much as other couples.
Psychologist MJ Ryan explains that kinder people live, on average lived 9 years longer than others, seemingly because it boosts their immune system.
Caring actually in many positive outcomes for the elderly (and I suggest it would happen no matter what the age). The 'giving' stimulated vasodilation, which is good for the cardiovascular system, and the white blood cell count goes up, thereby making us better able to fend off illness.