They divide opinion, no doubt about it - but love or hate 'em, tattoos are an ingrained part of our culture. Mixed opinions aside, a recent study conducted by researchers at the University of Alabama has found a surprising link between tattoos and our inner health.
The study, which was published in the American Journal of Human Biology, indicates people with multiple tattoos may have stronger immune systems than their un-inked counterparts.
The study compared saliva samples from 29 volunteers, aged between 18-47, before and after they got tattoos. Researchers were on the lookout for changes in the levels of immunoglobulin A, an infection fighting antibody - and cortisol - a hormone that weakens the immune response.
Those getting their first tattoo showed a dramatic decrease in immunoglobulin A, revealing that first-timers' resistance to infections is weakened. However, here's where it gets interesting; this drop was less pronounced among recipients who had multiple pieces of body art. This suggests that the immune system gets stronger over time.
In a press release, Dr. Christopher Lynn, Associate Professor of Anthropology at the University of Alabama said: "After the stress response, your body returns to an equilibrium, however, if you continue to stress your body over and over again, instead of returning to the same set point, it adjusts its internal set points and moves higher."