In a small, first-known study to document changes in the sweating function associated with tattooing led by Alma College in Michigan, researchers found that tattooed skin generated about half the amount of sweat as non-tattooed skin. They also found the sweat had a different composition, "containing about twice as much sodium as the non-tattooed side. The findings, published in Medicine and Science in Sports and Exercise, were the same if the tattoos were young or old," IFLScience.com reported.
The study involved 10 healthy men, all around the age of 21. Each had a tattoo on only one side of their upper body. The researchers chemically stimulated the sweat glands on both the tattooed and non-tattooed skin.
"To our knowledge, this is the first study of its kind to document alterations in sweating function associated with tattooing," lead author Maurie Luetkemier said in a statement. "However, we are somewhat cautious about our results. The process we used for stimulating sweat glands differs from the normal process, which involves cooling yourself following a rise in body temperature."
While this study was extremely small, the researchers believe this study could be used as a proof of concept for other studies that would allow others to dive deeper and uncover potential health risks that could be linked to this sweat difference.