When Australian swimmer Mackenzie James "Mack" Horton won gold in the 400 meter freestyle at the 2016 Rio de Janeiro Olympics, a mole was visible on his upper body. A fan noticed that this mole had not only become darker but had also taken on a different shape – both common characteristics of skin cancer. The fan then wrote an email to the gold medalist's doctor. As a result, Horton had the mole examined and subsequently removed. That fan may well have saved his life.

Like Germany goalkeeper Manuel Neuer, the professional swimmer has a light skin tone. When these people are exposed to intense sunlight for long periods of time, it can also expose them to too much UV radiation, which increases the risk of developing skin cancer. 

Sport alone can't prevent cancer 

Participating in sports, whether as a professional or recreational athlete, causes the body to release protective substances. These endogenous antioxidants intercept carcinogenic substances known as free radicals and form a protective barrier that can shield genetic material from intruders. Other factors, such as a healthy diet with plant-based foods coupled with omega-3 fatty acids and vitamin D, can also protect against cancer. 

However, there are no guarantees, as dermatologist and best-selling author Dr. Yael Adler told DW. Mack Horton and Manuel Neuer are both professional athletes and therefore eat a very healthy diets. 

"But when such a strong 'DNA poison' as the sun's UV radiation hits the cells, the 'body's own repair service' can still fail and you get cancer," Adler explained. 

Both of these athletes having a light skin tone is also a disadvantage as this "by its nature has fewer protective mechanisms." 

How does skin cancer develop? 

The intensity, duration and frequency of exposure to the sun are decisive factors in the development of skin cancer. 

"Those who had frequent sunburns as a child, for example, have a significantly higher risk of developing skin cancer," Professor Alexander Enk of Heidelberg University Hospital told DW. 

Enk, a former president of the German Dermatological Society, explained that it is not only the sun's UV-B radiation, which penetrates to the lowest layer of the epidermis, that damages the skin.

UV-A radiation, which reaches much deeper layers of the skin, is also a significant factor, he said, especially when it comes to black skin cancer. 

"It penetrates deeper into the skin and ages it faster because the collagen fibers are destroyed. Free radicals thus penetrate the tissue and go for the genetic material," he said. 

In addition, UV-A radiation can suppress the tumor defense system. 

Dangerous skin changes 

So how can you recognize skin cancer? Dermatologists agree: Any changes to one's skin, whether in terms of color or shape, should be examined by a doctor immediately. This means you must know your own body well. 

"But also, that of your partner," said Yael Adler. "When making love, leave the lights on sometimes. Then you'll notice any changes (to the skin)." 

Manuel Neuer raised awareness of the disease back in November. 

"If someone has a strange spot, it's better to say something once more than not to speak to someone," he said, after revealing that he had undergone three operations for skin cancer that had developed next to his nose – an area frequently exposed to the sun. Although the 36-year-old national team goalkeeper has since been cured, he has to undergo examinations every six months.  

How athletes can protect themselves 

Athletes who mainly train and compete outdoors need special protection. For example, in tennis, where top players like Angelique Kerber spend hours on an outside court. Kerber suffers from sun-related hyperpigmentation and is intensively exposed to dangerous UV radiation due to her profession. This also affects sailors, cyclists, runners and footballers like Manuel Neuer.   

Professor Enk advises athletes to avoid, when possible, the midday sun, by moving training to times of the day when the sunlight isn't as intense, as well as wearing the right clothing. 

"Certain textiles offer even better protection than various sun creams," he noted.

According to Enk, Australia is a role model in this regard. 

"There, where the sun's rays are the highest in the world, it's mandatory to indicate the UV protection factor on clothing," he said. 

Jerseys and training pants that have been tested and bear a seal of approval are best. This has long been the norm for golfers, "because too often they are exposed to the sun for long periods of time."

Skin cancer on the rise 

Enk sees the fact that Neuer went public with his experiences with skin cancer as as stroke of luck in efforts to raise awareness of the dangers. Educational campaigns supported by the government and professional associations have failed to produce the desired effect. According to statistics from German health insurance companies, the incidences of skin cancer rose by 91% between the years 2010 and 2020. 

Dermatologists continue to stress the need for athletes – and others – to take steps to protect themselves from the sun's harmful UV rays — and to go for regular check-ups. And keep an eye on those around you, as pointing out any changes in somebody's skin can save lives — as probably was the case with Mack Horton.

This article was translated from German.