Halotherapy should be taken with a grain of salt

Dear Doctor:

I keep hearing about something called halotherapy, or salt therapy. Can it really help people who have respiratory problems and inflammation? I’ve heard that it’s good for arthritis and for regulating blood pressure, too.

Dear Reader: Halotherapy is a centuries-old spa treatment that’s definitely having a moment. Although the specifics of the practice are as varied as the establishments that offer it, it basically involves inhaling salt particles that have been rendered minute enough to be breathable.

Enthusiasts promote halotherapy as an alternative treatment with, as you point out, a wide and diverse array of purported benefits. These range from help with respiratory issues, infection and a variety of skin conditions, to relief from anxiety, depression, inflammation and immunity problems. Skeptics, including some in the medical community, consider halotherapy to be a pseudoscience.

The medicinal use of salt dates back at least to the ancient Egyptians, where it was cited in papyrus manuscripts as an effective antibiotic, skin treatment, birth aid and laxative. These practices then found their way to the ancient Greeks and Romans and the early Arab world, and they were later adopted in Europe during the Middle Ages, the Renaissance and beyond.

The modern practice of halotherapy arises from observations made by physicians living near the salt mines of Eastern Europe and Russia at the start of the 19th century. They noticed that unlike laborers who mined ore or coal, work that took a steep physical toll, salt miners had no respiratory problems and remained in relatively good health. This was attributed to the microparticles of salt created in the course of mining operations, which the miners breathed throughout their working hours and also had on their skin.

This discovery led to the founding of a health resort in the 1840s -- and later to numerous spas and resorts -- where patrons spent time inside salt caves, breathing and exercising. Today, spas and other facilities build their own salt caves using tons of rock salt. A grinding machine is used to reduce salt to microparticles, which are circulated throughout the space for patrons to breathe during timed sessions.

Health claims regarding halotherapy are abundant -- and largely anecdotal. A handful of studies published in the last decade have linked halotherapy to varying degrees of improvement among individuals with chronic respiratory issues such as asthma and COPD. However, questions about methodologies, including randomization and patient selection, have called some of those conclusions into question. At this time, rigorous scientific studies into the practice remain scarce.

When it comes to how halotherapy works in cases of respiratory illness, no one really knows. Proponents point to the antibacterial and antifungal properties of salt. Some believe the salt-laden air helps to thin out mucus, which allows for improved function of the body’s natural immune processes and cleansing mechanisms.

If you do give halotherapy a try, make sure the facility provides adequate ventilation. One study found increased levels of bioaerosols, which are minute biological airborne particles, in underground salt caves used by groups for therapy and exercise. And since salt is a diuretic, we think it’s wise to replenish fluids and use moisturizing eye drops when you’re done.

Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health.