Tattoos and body art are now big business. The tattoo industry alone is pushing $2 billion in yearly income, which has almost doubled over the last 10 years. Interestingly, tattoo removal makes up one-third of that figure - and steadily increasing each year.
14.5% of Australians have at least one tattoo. Almost half are applied after 26 years of age and 10% after 40. And if you have one, you're a 45% chance to end up with more than one.
Not to be outdone, tattoos adorn 21% of Americans as well. One-third of Americans between 18-29 have a tattoo with 70% of all ages having more than one.
Amazingly, people are even developing the technology to turn your freckles and birthmarks into smartphone controls via E-tattoos. Perhaps electronic tattoos will be the next frontier in tattooing?
But as the human body becomes a greater canvas for artistic expression it can be easy to neglect any potential side-effects.
The risk of skin infection and the need for proper aftercare aside, a study has found another more obscure side-effect to tattooing.
One that may have ramifications for your ability to sweat.
The Process of Tattooing
Before getting to the study itself it's important to understand a little about the process of tattooing.
An electronic needle is often used to apply the pigment for modern tattoos. The needle is designed to puncture through the skin's top layer (Epidermis) down into the deeper layer (Dermis).
The Epidermis is considered the protective layer of our skin. The Dermis houses our hair follicles, touch and heat receptors, lymph, blood and other vessels and glands - including our sweat glands.
As a small study has found, controlled damage to this Dermal layer via tattooing may have some unintended consequences for those sweat glands.
The Role of Sweat Glands
Sweat glands are everywhere but located in greater density in the skin of the forehead, underarms, palms of hands and soles of feet.
The main role of sweat glands is to help cool us down and regulate body temperature. As our sweat evaporates it cools the surface of our skin and helps improve the grip of our hands and feet in smaller doses.
Tattoos Effect Your Ability to Sweat
Now with this in mind, it interesting to read a study from Michigan, United States. It looked at the effects of tattooing on our ability to sweat.
M.J. Luetkemeier and friends took ten participants and compared sweat rate and sweat composition between a tattooed area on one side and a non-tattooed area on the opposite side.
They used an Iontophoresis machine to electrically stimulate areas of at least 5.2 cm to make the participants sweat.
And it found some interesting results.
They found the tattooed side accounted for a 53% lower sweat rate. They also noted a 64% higher sodium concentration when compared to the non-tattooed side.
Essentially they found that having a tattoo causes the area to sweat less, but with a higher rate of electrolyte loss.
Considering the skin's dermis also houses other receptors, vessels, and glands, it raises an interesting question as to the broader impact of tattooing on our Dermal function.
Is this yet another physical sign the modern world is taking its toll on us?
Limitations
As with every study, it's important to discuss its limitations. Many fall into the trap of taking results as gospel without considering the study's flaws. If big enough, any potential flaws can short-circuit our ability to generalize any findings to the wider population.
This study has a few that need our consideration.
For starters, a few things about the participants need clarification. Clearly ten is a very low number. All ten did have statistically significant reductions in sweat but it's hard to categorically rely on this without greater numbers to go off.
Similarly, all participants were between the ages of 20 and 22. These results may relate to those outside this range, but we can't know for sure.
Furthermore, tattoo ink is not a uniform product across the tattoo industry. Because of this, it's hard to know which ingredients may affect sweat more than others. We would need a much larger study encompassing the most common ink used in tattoos to better understand any relationship.
We also don't know how these results relate to different sized tattoos or even something like a full sleeve. Do different colored ink effect sweat rate and composition differently as well?
And finally, the study facilitated sweating with the help of Iontophoresis. Iontophoresis isn't necessarily the same sweat-producing stimulus as a warm day or exercise. We may need to include these specific triggers in future research for a better understanding.
Related: Here's why I'm at odds with evidence-based practice.
Conclusion
The results of this study do make for interesting reading.
If you are someone who has a small tattoo, perhaps the effects on your sweat are negligible at best.
But if you are someone whose tattoos cover a decent amount of your body, this may be something to consider. Not that you can do much to immediately change things of course, but it may be worth taking note regardless.
If you're an active person perhaps try wearing more breathable clothes and see if that makes a difference to how hot you feel. Similarly, you may need to watch those electrolytes a little more thanks to your tattoos.
Either way, this study highlights that tattoos may have other potential side-effects than the ones we often talk about.
Do you have any tattoos? If so, do you notice any effects similar to the study above?
Let me know in the comments below.