A 2016 study published in the American Journal of Human Biology indicates that getting several tattoos over time can make your immune system stronger. This does not mean, however, that getting a tattoo will immediately improve your overall health and reduce the likelihood of getting the flu this year. The study does indicate that someone who has had several tattoos experiences less suppression of the immune system than an individual getting tattooed for the first time. In this way, the body of the tattoo "veteran" toughens up, similar to the way in which exercise strengthens muscles.
When someone receives a tattoo for the first time, his or her immune system is strained due to the increase in the stress hormone cortisol. High levels of cortisol result in immunosuppression, making the immune system less able to protect against infections. However, this reaction lessens each time a person receives an additional tattoo. There is less immunosuppression and the immune system remains better able to fight infections.
Although the American Journal of Human Biology study may provide a greater incentive for tattoo lovers to indulge in their hobby, critics argue that this study is not definitive. They point to one potential flaw in the study design -- the fact that the researchers did not consider whether the study participants had strong immune systems in the first place.
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