Tattoos alter the skin’s ability to produce sweat and result in higher concentrations of sodium, a study shows.
Researchers from Alma College in Michigan examined the tattoos of 10 men. The tattoos covered a circular area of skin of at least 5.2 cm. Researchers used agar gel disks containing 0.5% pilocarpine nitrate to stimulate sweat by iontophoresis in the tattooed skin, as well as in nontattooed skin located contralaterally to the tattooed skin. The disks were weighed before and after sweat collection to assess the amount of sweat produced.
Every participant generated less sweat from the tattooed skin than from the nontattooed skin (0.18 ± 0.15 vs. 0.35 ± 0.25 mg•cm•min; P = 0.001). The mean sweat Na concentration from the tattooed skin was found to be significantly higher than from the nontattooed skin areas (69.1 ± 28.9 vs. 42.6 ± 15.2 mmol•L; P =0.02).
Reference: Luetkemeier MJ, Hanisko JM, Aho KM. Med Sci Sports Exerc. 2017;49(7)1432-1436.