Do tattoos impair the skin’s ability to sweat? Despite the global ubiquitousness of tattoos this question has received surprisingly little research attention. A new, first-of-its-kind study is suggesting inking skin may damage sweat glands and reduce the body’s ability to rapidly cool itself.
Back in 2017, Alma College’s Maurie Luetkemeier conducted one of the first rigorous modern studies investigating whether tattoos interfere with the basic function of our sweat glands. The researchers used a tool called the Macroduct Sweat Collection System, which uses a small electric current to induce sweating and is commonly used to sweat-test newborns as a way of early screening for cystic fibrosis.
Luetkemeier’s initial study provided the alarming finding that tattooed skin seemed to produce around half the amount of sweat as clear, non-inked skin. The sweat arising from tatted skin was also found to be significantly saltier that normal, suggesting the tattoo ink could be disrupting the function of the sweat glands.
“However, we are somewhat cautious about our results,” Luetkemeier noted back in 2017. “The process we used for stimulating sweat glands differs from the normal process, which involves cooling yourself following a rise in body temperature.”
Last year, a team of Australian researchers followed up on Luetkemeier’s experiments, testing how tattooed skin responds to real-life exercise conditions. That study essentially measured individual sweat rates across different skin locations in 22 subjects. After 20 minutes of exercise the researchers saw no difference in the volume of sweat produced between inked skin and non-inked skin.
“The previous study showed having a tattoo reduced localized sweat rate and increased sweat sodium concentration,” reported Australian researcher Ben Desbrow last year. “However, the sweat response was triggered using an artificial stimulation technique rather than under exercising conditions. Our data suggest that skin tattoos do not alter the amount or sodium concentration of sweat produced in response to exercise.”
Introducing his new study, Luetkemeier and colleagues push back on the contradictory findings from the Australian study, suggesting that as internal or skin temperature was not recorded in the prior Australian research, it is difficult to know whether thermal-induced sweating is disrupted by a tattoo. So, this new study used yet another experimental approach to investigate the increasingly divisive question.
The researchers recruited 10 tattooed individuals and placed them in a tube-lined suit designed to perfuse warm water over the entire body. This allows the researchers to investigate exactly how much thermal-induced sweat is produced by tattooed skin.
The findings reveal no difference in the onset of sweating between tattooed and clear skin, which suggests the neural signaling that triggers the body’s sweat response is not altered by tattoo ink. However, the tattooed skin did produce less sweat than the adjacent non-tattooed skin, and the sweat produced by the tattooed skin was saltier.
“Combined with previous studies, which also suggested potential functional damage of the eccrine sweat gland duct, there appears to be long-term consequences of the tattooing process that have not previously been considered,” the researchers write in the new study.
Compared to Luetkemeier’s 2017 study, which found tattooed skin produced around 50 percent less sweat than clear skin, this new research saw the tattooed skin producing only around 15 percent less sweat. The differences between the two findings are yet to be understood but the study hypothesizes the variations could be explained by the mechanical differences between the two experimental methods used to induce sweating.
So in the end, it still is unclear exactly how tattooing is affecting sweat glands in the skin. The jury may still be out, but Luetkemeier and his colleagues are confident a tattoo does, in some way, damage a person’s sweat glands, and this could be clinically relevant in persons with extensive tattoos covering large areas of their body.
“These data suggest that tattooing functionally damages secretion mechanisms, affecting the reflex capacity of the gland to produce sweat, but does not appear to affect neural signaling to initiate sweating,” the researchers conclude in the newly published study. “Decreased sweating could impact heat dissipation especially when tattooing covers a higher percentage of body surface area and could be considered a potential long-term clinical side effect of tattooing.”
The new study was published in the Journal of Applied Physiology.
Source: American Physiological Society
