Science Explains: Tattoos

For some students, it is a somewhat reckless and often drunken decision regretted instantaneously after a great night out. For others, it is a beautiful work of art with sentimental meaning. Whatever the reason, the increasing use of our own bodies as a blank artistic canvas for permanent inked drawings is hard to ignore; humans have marked themselves since the dawn of civilisation. It is estimated that 40% of young adults aged between 18-29 years old have at least one tattoo. The question still remains about their impacts on our health; most of us would have at least some inkling that injecting unknown dyes deep into our skin with needles may not seem like the safest idea. There is some evidence however to suggest that these inked drawings may actually be beneficial.

It is estimated that 40% of young adults aged between 18-29 years old have at least one tattoo

Tattoos are a type of body modification where ink, dyes and pigments are inserted into the skin using a needle in order to change the pigment. If administered correctly, the ink should end up in the dermis. This is the thick middle layer of skin beneath the epidermis (outer layer of skin) and is ideal for creating a permanent image. Why inject so deep into the skin? Injecting the ink into the upper epidermis would be a fruitless affair; this layer of skin is constantly growing new skin cells and shedding the old ones. Any dyes placed there wouldn’t last long at all. The cells of the dermis however don’t replace themselves in the same way; this makes the artistic designs permanent. The reason behind the considerable pain of tattooing also lies in the dermis; this layer of skin is home to nerve endings, meaning that every prick with the needle can be felt.

Whilst the body art can look fabulous, its needless to say that there are inky issues with tattoos. Many people have harmful allergic reactions to the inks, unsurprising when considering that the pigments that give these inks their colour were made with printers and cars in mind, not humans. No ink is currently approved by the FDA (Food and Drug Administration) for use in human skin. Others may have trouble getting certain medical tests. Tattoos containing metal can interfere with MRI scans, distorting the images they generate and also potentially burning the skin due to the heating of the metal by the MRI magnet. Infections from unsterilised equipment are also common. Tattoo removal for those that change their minds is a long and painful process involving laser treatment.

Injecting the ink into the upper epidermis would be a fruitless affair; this layer of skin is constantly growing new skin cells and shedding the old ones

However, some new studies are revealing that tattoos may have some positive impacts on our health by boosting our immune system. Cortisol is a stress hormone that when released lowers the body’s immunity. One of the ways it does this is by reducing the levels of an immune antibody called Immunoglobulin A (IgA), which protects mucosal surfaces in the gastrointestinal tract and upper airways. One study tested the levels of cortisol and immunoglobulin A before and after getting a tattoo. IgA levels fell significantly after tattooing, probably due to an increase in cortisol. Getting inked is, after all, a somewhat stressful affair. However, people who already had a tattoo experienced a much smaller drop in their IgA levels; the level of immunoglobulin also returned to the normal level much more rapidly. The immune system appears to recover faster in tattooed individuals and is therefore more efficiently primed to target any infections. Put simply, the more tattoos a person gets, the stronger their immune system gets.

Good or bad, planned or unplanned, sentimental or purely artistic, it’s hard to deny that tattoos have truly made their mark on society. Whilst there are always risks with any type of body modification, it’s possible that tattoos may have some benefit to our immune systems.