Koreans are embracing barefoot walking. Doctors aren't so sure.

Koreans are flocking to clay trails to engage in barefoot walking, or "earthing," which advocates claim can bring health benefits. Doctors say it puts them at risk of disease and infections.

Two men walk barefoot on Daemo mountain on Dec. 9. [KIM JU-YEON]

Thirty to 40 people gathered at the base of Daemo mountain on an unusually warm winter day in early December. Their plan was simple: Walk barefoot outdoors.

The participants had two glaring things in common. They were of an older demographic, and they were intrigued by the promise of a “naturally healing” cure-all remedy.

“We came because we heard walking barefoot was good for curing cancer,” said Kang, a woman in her 70s who received chemotherapy for rectal cancer two years ago.

Walking barefoot, also called “earthing” or “grounding,” is all the rage in Korea for its claimed health benefits.

But while earthing's murky scientific backing leaves experts skeptical or downright dismissive of the necessity of going barefoot, local governments have been funneling billions of won into clay trails tailored to the practice, which advocates promoted with the same questionable medical claims.

Kang, who had come with three other cancer patients, was one of many who'd come to the event hoping to cure a chronic or “lifestyle” disease.

“As I hit my 60s, my hormones changed and I couldn’t go to sleep,” a man in his 60s said. “I heard walking barefoot was good for insomnia through YouTube. I thought it was just good for acupressure effects, but there seemed to be a solid scientific backing to it. It was even shown on TV.”

Though it was the man's first time trying the practice out, he wore socks with holes cut out to allow him to “receive earthing effects” but prevent frostbite — a tip he'd picked up from YouTube.

Participants listen to ″Walking barefoot movement″ community founder and head Park Dong-chang's lecture on the benefits of earthing at a barefoot walking training session held on Dec. 9. [KIM JU-YEON]

Disheartened patients in Korea give earthing a go Advocates claim that barefoot walking brings a number of benefits: enhanced immunity, anti-inflammatory effects, anti-aging effects, improved blood flow, acupressure effects, strengthening of foot muscles, and improved mental health.

But their main argument for going barefoot, and the most controversial, is that the practice can cure diseases.

Adherents have argued that the skin's contact with the earth's electric field allows for electrons to spread over and into the body, creating an electrical homeostasis optimal for health. Specifically, the electrons are hypothesized to dissipate static electricity to reduce oxidative stress, a condition linked to various health conditions.

The internet is full of online “testimonials” claiming that walking barefoot has cured insomnia, late-stage cancer, diabetes, headaches, brain tumors, dementia and even infertility.

Koo, a man in his 70s, said he saw his blood sugar level drop below 6.5 percent for the first time after beginning to walk barefoot in June. His blood sugar level hovered around 8 percent when he was diagnosed with diabetes 20 years ago, and fell to the 6.7 to 7 percent range after Koo made various lifestyle changes including embarking on a rigorous exercise regime. After walking barefoot for around six months, he saw his numbers dip below 6.5, into a healthy range recommended by doctors.

“To be honest, I can’t say for sure that walking barefoot is the only reason behind it. It [the healing process] must be complicated. But the [blood sugar] figures prove it. And you can’t ignore the psychological aspect of going barefoot,” Koo said. “The belief that you can get better by doing this makes all the difference.”

But is walking barefoot really a miracle cure? Probably not, experts say.

People walk down Daemo mountain barefoot for earthing effects. [KIM JU-YEON]

Earthing’s medical effects don’t pass clinical scrutiny “There is nothing medically proven,” when it comes to the health impacts of earthing, said Ahn Hee-kyung, an oncologist at Gachon University Gil Medical Center.

Ahn is not alone in this matter. Traditional doctors and scientists say the claimed benefits of earthing aren’t grounded in rigorous research or clinical trials.

“Just from the perspective of basic physics, earthing makes no sense. There is also no research establishing the basic underlying claim — that there is an electrical homeostasis that has any effect on how the body functions, and that this is affected by grounding,” said Dr. Steven Novella, a neurologist at the Yale School of Medicine, on his website, Science-Based Medicine.

Novella also criticized the fact that much of the medical “evidence” that earthing's advocates cite relies on preclinical studies that merely state the occurrence of a phenomenon and are not predictive of the same effects being replicated.

Many research papers that have been published on the subject, mostly in “alternative medicine” journals, contain small sample sizes, poor design and a focus on self-testimonies and subjective outcomes such as “well-being” and stress.

Many also show conflicts of interest. Authors of the most-cited research papers on earthing’s medical effects were actually independent contractors sponsored by EarthFx, a company that sells earthing equipment, and “own a small percent of shares in the company.”

The director of the Earthing Institute, which funds research and education about earthing and grounding, says that they “surmise, but don’t have direct research, that earthing will help slow the aging process.”

Nevertheless, the incomplete English-published research has found its way to Korea. A YouTube video widely shared among the Korean earthing community, for instance, shows a woman with reduced blood viscosity after walking barefoot for 10 minutes, but does not compare her to a control.

While doctors do encourage walking, they say that going barefoot isn't necessary to benefit from the exercise.

“Proper walking and movement improve the core strength of feet and ankles and are good to improve metabolism. But going barefoot isn’t necessary to gain these effects,” said Lee Young-koo, an orthopedic doctor at Soonchunhyang University Bucheon Hospital.

In fact, it could be particularly dangerous for cancer and diabetes patients, as well as elderly people — those who seek out the activity the most — to go barefoot, as they risk unknowingly catching infections from bacteria on the ground.

Lee says that people with diabetes, who can have weakened senses as well as damaged nerves and blood vessels in their feet, are more prone to wounds, which can be particularly pernicious when infected with bacteria. In the worst cases, infections from bacteria such as Staphylococcus could lead to amputation or even death.

Shoes act as protective devices and add stability to feet, which need care, as they support the whole body’s weight, said Lee. Recently, he's seen an influx of patients seeking treatment for inflammation, infection and damaged nerves after walking barefoot.

Those with cancer have additional reasons to steer clear. “Cancer patients are already weakened by chemotherapy, which commonly causes the skin on the feet to peel off and causes peripheral neuritis, a condition referring to damaged nerves,” said Ahn.

Walking barefoot requires a better sense of balance than with wearing shoes does. People with diabetes and elderly people, who may already have peripheral neuropathy, have a higher risk of falling, Ahn says.

Ahn, like Lee, has seen patients asking for medical advice on how to walk barefoot safely, with an increasing number requesting tetanus shots. But Ahn warns that there are a multitude of bacteria, not just tetanus, that could damage patients with weakened immune systems, and “infection can happen through even very small cracks in the skin.”

“Shoes were invented to protect our feet and stabilize us. When weighed with the dangers of walking barefoot such as infection, there is no reason to recommend people to go barefoot,” Ahn said.

People with shoes and barefoot people alike walk on the regular trail and Gyejoksan Red Clay Trail at Gyejoksan Mountain, Daejeon. Picture taken on Oct. 8, 2023 [YONHAP]

Walking barefoot movement leaves its mark on Korea Despite its questionable scientific backing, earthing's “effects” have been used as evidence to support the creation of red clay trails designed for barefoot walking at government policy forums in Seoul and Seongnam, Gyeonggi. As more people take up the activity, cities all over Korea have scrambled to accommodate the demand for trails and spent large sums in the process.

In 2023, the Seongnam government spent 3.45 billion won ($2.7 million) to build six red clay trails. The city has set aside an additional 3.5 billion won to create five more trails and extend an existing one, according to its budget plan for 2024.

Sinan County plans to finish building a 14-kilometer (nine-mile) red clay trail, the longest in the country, by 2026. New red clay trails were also paved in Seoul and numerous cities in Gyeonggi including Suwon, Yongin, Goyang, Guri and Uiwang last year.

It's not just barefoot enthusiasts that are welcoming the new trails — they're a relief to wildlife and historical preservationists as well.

SBS reported in November that people were damaging ecosystems by walking in restricted areas designated to protect wildlife, including in mud flats and mountains. The Cultural Heritage Administration put up a notice in March prohibiting people from walking barefoot around the Joseon Dynasty royal tombs after complaints were filed that people were crowding public bathrooms to wash their feet.

Pictured is a red clay trail on a rainy day at Yuldong Park, Seongnam. [SEONGNAM CITY]

But red clay trails also pose some logistical problems.

Reports show that Korea’s heavy summer rains often flood clay trails, rendering them and nearby paths unfit for use as puddles form and wet clay make them slippery.

The trails also cannot be used in the winter and need to be closed to prevent people from incurring frostbite and wounds from walking on the frozen dirt. The clay can also dry up and crack under strong summer heat, potentially burning bare soles, without proper maintenance.

Kang Ho-seop, a Seongnam government official in the Park Department, says workers sprinkle water onto dry clay in the summer and fill in empty patches with new clay once they get bare. They also comb through the clay to check for any sharp objects or debris, Kang said.

But that maintenance comes with costs. Seongnam plans to use 150 million won next year for maintenance of its existing clay trails, not including the fees used to pay workers who maintain those trails and construct facilities. The CEO of Mackiss Company, which used private funds to create a red clay trail at Gyejoksan Mountain in Daejeon, reported that maintaining one trail requires one billion won and 2,000 tons of red clay per year.

Despite doctors' warnings, barefoot walkers remained firm on their convictions as they ascended Daemo mountain. “Wild animals do not get sick," said Park Dong-chang, founder and head of the “walking barefoot movement” community in Korea as walkers prepared for the session. "Stay connected to the earth."

BY KIM JU-YEON [kim.juyeon2@joongang.co.kr]