If you’re anything like me, summer means channeling your inner Nicholas Sparks’ character by swimming in the ocean waves and soaking up all those positive beach vibes. But while swimming in the ocean is incredibly fun, the health risks of ocean swimming might include a change in your skin microbiome, potentially increasing your risk for infection, according to research presented at ASM Microbe 2019, the annual meeting of the American Society for Microbiology.
In these sun-soaked summer months, it’s important to be aware of how our quintessential warm-weather activities can sometimes pose potential risks to our skin. As the human body’s largest organ and the first line of defense against outside contaminants, the skin plays an important role in helping our bodies fend off infections and disease. The skin’s microbiome is home to a community of organisms like bacteria (and some fungi!), many of which are vitally beneficial to your health.
But if your skin's microbiome is compromised, it can increase your likelihood of developing an illness. And that’s exactly what researchers say can happen when your skin is exposed to the briny ocean water. "Our data demonstrate for the first time that ocean water exposure can alter the diversity and composition of the human skin microbiome," says lead author Marisa Chattman Nielsen, a PhD student at the University of California, was quoted as saying in a press release. This can potentially cause gastrointestinal and respiratory illness, ear infections, or skin infections. Swimming in salt water can also dry out your skin.
Nielsen and the other researchers went to the beach and recruited nine volunteers for their study (which, granted, isn't a ton of people). Each volunteer had to meet the following criteria: not using sunscreen, infrequent exposure to the ocean water, no bathing within the last 12 hours, and no antibiotics during the previous six months. After the volunteers swam in the ocean for 10 minutes, researchers analyzed the findings.
During the study, these researchers were able to detect the presence of ocean bacteria on participants' skin for over 24 hours post-swim. Other participants no longer showed signs of ocean bacteria after a mere six hours. “While swimming, normal resident bacteria were washed off while ocean bacteria were deposited onto the skin,” says Nielsen.
One bacteria called the Vibrio species — a genus of bacteria that includes cholera-causing bacteria — was detected on every participant after they air-dried the ocean water from their bodies. However, only one person showed signs of Vibrio after 24 hours. Perhaps more concerning, the press release says that researchers found that, on human skin, the Vibrio species “was more than 10 times greater than the fraction in the ocean water sample, suggesting a specific affinity for attachment to human skin.”
This is also an environmental issue, as this research was spurred by previous studies that showed a “high prevalence of poor water quality at many beaches, due to wastewater and storm-water runoff. Climate disaster — including ocean pollution — is intrinsically linked to human health risks, so it’s important to be aware of this dynamic as well. Helping to reduce pollution and clean-up your local natural swimming pools may go a long way towards making the beach safer.
So does all this mean that you have to stop swimming in the ocean? Not really. The research only examined the skin of nine volunteers, so while it's illuminating, it's hardly definitive. Also, if you like swimming in the ocean, do it! There are many social, mental, and physical benefits to ocean swimming. Just take all the precautions you'd take swimming anywhere else. Still, it’s good to be aware of this research to keep your skin's microbiome healthy.
One other way you can keep safe is paying attention to warnings about certain bodies of water that may be unsafe. For example, Los Angeles lifeguards have recently said the algae in a local lake is giving them rashes and infections. Also, if you have any kind of open cut or wound, it’s best not to get in salt water, as bacteria can get into your skin and cause infection. Summer is supposed to be a fun time, but your health and safety is most important.