Scientists at the University of Alabama have found that tattoos boost health. The study, published in the American Journal of Human Biology, states that people with multiple tattoos have a stronger immune system than their un-inked or less-inked counterparts. Saliva samples of over 29 volunteers indicated a fall in immunoglobulin A, an infection-fighting antibody, after getting the first tattoo; but as the number of body art increased, the same antibody got stronger, strengthening the immune system over time.