That cheeky holiday tan you’re planning on getting this summer could be hurting your skin’s microbiota, according to research.

Our skin is host to a variety of fungi, bacteria, and viruses that make up our microbiota. 

These healthy bacteria live on and in us, protecting us from germs known as pathogens. 

In their study published in August, scientists from the University of Manchester say getting tanned or sunburnt can lower the healthy bacteria’s abundance.

Done in collaboration with the No7 Beauty Company, the research found that the microbiota can change in as little as seven days due to sun exposure.

Dr Thomas Willmott, lead author of the study, says “sun exposure resulting in a tanning response – even over a relatively short sunny period – can lead to an acute reduction in Proteobacteria abundance, which decreased skin microbiota diversity”.

Proteobacteria is one of three main bacterial communities making up the microbiota and is particularly sensitive to ultraviolet radiation (UVR), which is emitted from the sun. 

According to the study, “a Proteobacteria imbalance may suggest decreased skin health in those sun-seeking individuals” - making you more susceptible to diseases.

The study saw 21 participants sent to a sunny destination, where they were to go about their usual holidaymaker behaviour. 

The colour of their skin was measured before they left, then again immediately after returning and on days 28 and 84 post-holiday.

Researchers were able to split participants into three categories of study. 

Those who came back more tanned than they had left were called ‘sun-seekers’. 

Those who left with fair skin and came back with little or no tan were ‘avoiders’ and people who left with already tanned skin and came back with little to no change were ‘tanned’.

They found only the sun-seeker group had a significant change in microbiota makeup, specifically a decrease in Proteobacteria. 

While the bacterial communities living on the skin did bounce back to their original state quickly, researchers clocking the recovery at day 28 said the damaging effects this could be having on skin health shouldn’t be ruled out.

The change in richness and diversity of the skin’s microbiota is linked to a variety of diseases, like dermatitis, as well as damage to DNA in skin cells, inflammation, and premature skin ageing. 

A reduction in proteobacteria caused by UVR is specifically linked to skin conditions like eczema and psoriasis.

Despite the risks, many still seek out that perfect tan while on holiday. But why?

In Western culture, a tan is often associated with attractiveness, health, and well-being - all social pressures that have made the look so popular. 

According to the researchers, “differences in sun exposure behaviour as observed in this study are likely influenced by both social pressures and cultural beliefs.”

They also say deconstructing those underlying sociological reasons behind tanning could be critical in reducing incidences of skin cancer on a global scale. 

But the tanning trend is more than skin deep - it’s neuropsychological. 

Prior research done by the University of Texas Southwestern Medical Centre has found that low doses of UVR exposure elevate endorphins in the skin that block pain and produce pleasure, meaning the act of tanning also has an addictive kick. 

Scientists at the University of Manchester say this could also play a role in tanning tendencies, and that “it is important to raise awareness to holidaymakers of the risk factors associated with sun-seeking behaviours.”

The long-term effects of the bacterial shift in the microbiota are currently unknown, however, researchers are hopeful that future studies will be able to provide more answers. 

For now, find some shade, block up, and don’t underestimate the power of a hat.

More stories:

Cheap rent, compromise and stigma: What it's like living with your parents in your 30s

Is it time we get over the stigma of living with your parents as an adult?

Why I kept my ex’s clothes

Breakups suck but sometimes you get a new jumper out of it.

Half of all cosmetics have ‘forever chemicals’. NZ wants to ban them

Here’s how it might impact your long-wear makeup.