Sun exposure during vacation can impact your skin microbiome, leading to eczema.

Sun exposure during vacation can impact your skin microbiome, leading to eczema.

The Effects of Sun Exposure on the Skin Microbiome


When we go on vacation, soaking up the sun and getting a tan is often high on our to-do list. However, recent research suggests that our sun-seeking behavior may have unintended consequences for the health of our skin. A study conducted by researchers found that exposure to the sun during vacation leads to short-term changes in the skin microbiome, which could potentially cause conditions such as eczema.

The human skin is home to a complex ecosystem of bacteria, fungi, and viruses, collectively known as the skin microbiome. These microorganisms play a crucial role in maintaining the overall health and balance of our skin. It is well-established that prolonged exposure to ultraviolet radiation (UVR) from the sun can damage the DNA in our skin cells and lead to inflammation and premature aging. However, there is limited research on how UVR specifically affects the composition of the skin microbiome.

Some studies suggest that UVR may have positive effects on the skin by reducing the levels of harmful bacteria. However, other research indicates that imbalances in the skin microbiota caused by UVR exposure can lead to chronic inflammation and conditions such as eczema and psoriasis. With these conflicting findings, further studies are needed to fully understand the long-term implications of sun exposure on skin health.

The recent study on sun exposure and the skin microbiome investigated the effects of short-term holiday-related sun exposure on the skin. The researchers recruited 21 North European residents, who were divided into three groups based on their sun exposure habits: “Seekers,” who actively sought out a tan during their vacation, “Tanners,” who already had a tan and maintained it while abroad, and “Avoiders,” who did not tan and maintained their original skin tone.

Skin swabs were collected from the participants before they went on vacation, immediately after their vacation, and 28 and 84 days later. The results of the genetic analysis of the skin samples showed that there were three main types of bacteria present in all samples: actinobacteria, proteobacteria, and firmicutes. Immediately after the vacation, the “Seekers” and “Tanners” had significantly lower levels of proteobacteria compared to the “Avoiders.” However, by day 28 and day 84, the levels of proteobacteria had returned to pre-holiday levels. The levels of actinobacteria and firmicutes remained consistent across all groups throughout the study.

Dr. Adela Rambi G. Cardones, a professor and chief of the Division of Dermatology at The University of Kansas Health System, who was not involved in the study, noted that these findings suggest that increased sun exposure or tanning during a sunny holiday leads to short-term shifts in the skin microbiome. However, further research is needed to understand the underlying cause of these shifts and their ultimate health implications.

One potential explanation for how sun exposure affects the skin microbiome is that it alters the balance of bacteria on the skin surface. Dr. Adelaide Hebert, a professor of dermatology with McGovern Medical School at UTHealth Houston, explains that the UV radiation may disrupt the normal bacteria on the skin, leading to imbalances that can trigger an inflammatory response. This inflammation is often associated with conditions like eczema and dermatitis.

Previous research has shown that decreased levels of proteobacteria, one of the bacteria types affected by sun exposure in the study, are linked to skin conditions such as eczema. However, it is still unclear whether there is a causal relationship between the two. Dr. J. Wes Ulm, a bioinformatic scientific resource analyst at the National Institutes of Health, emphasizes the importance of further studies to determine the precise mechanisms and connections between the skin microbiome and conditions like eczema.

It is worth noting that this study has some limitations. The sample size was small, and the study mainly included British vacationers. Therefore, the findings may not be applicable to other demographics. Additionally, the study did not take into account other factors such as sunscreen usage or activities performed during the vacation.

It is reassuring to know that the skin’s microbiome naturally restores itself after a period of limited sun exposure. The short-term shifts observed in the study do not appear to significantly increase the risk of eczema or dermatitis in the long run. However, the long-term effects of repeated sun exposure on the skin microbiome remain uncertain. Further population-level studies conducted over a span of several years would provide valuable insights into this matter.

In conclusion, while enjoying the sun during vacation is a popular pastime, it’s essential to be mindful of the potential impacts on our skin health. Moderation and sunscreen usage play crucial roles in protecting our skin from the harmful effects of UVR. The study on sun exposure and the skin microbiome adds another factor for vacationers to consider and guides future research directions. Understanding the intricate relationship between the skin and the sun will help us make informed decisions about sun exposure in the pursuit of healthy skin.