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The Nuance
Do Epsom Salt Baths Actually Do Anything?
The murky science behind the age-old ritual
Every week, the Nuance will go beyond the basics, offering a deep and researched look at the latest science and expert insights on a buzzed-about health topic.
Epsom salt has been around for centuries; medical texts from the early 1900s refer to it as an “old medicinal friend.” But despite its musty history, Epsom salt is lately enjoying a renaissance. You can’t walk into a spa or pharmacy without bumping into a display case full of these magnesium sulfate crystals, and lifestyle gurus like Gwyneth Paltrow extol the detoxifying benefits of soaking in a tub enriched with them.
Epsom salt takes its name from a wellspring in Surrey, England, that was discovered in the early 1600s. The spring’s saline waters were thought to have healing properties, and people started believing that bathing in its waters could relieve sores and infections. Today, some believe Epsom salt can relieve everything from stress and muscle soreness to arthritis-related joint pain. Proponents also say that by leaching into the body’s cells during a soak, Epsom salt can improve heart and vascular health, lower the incidence and severity of diabetes, flush away toxins and harmful heavy metals, and improve nerve functioning.
“I don’t think it’s true that magnesium can get in through the skin.”
But there isn’t much evidence to support these claims. “You will find some benefits of magnesium given intravenously or orally, but the data on soaking is weak and not conclusive,” says Mark Moyad, MD, director of preventative and alternative medicine at the University of Michigan.
The main scientific tentpole around which many Epsom salt aficionados base their beliefs is an experiment from the University of Birmingham in the UK. Researchers found that people who soaked in magnesium sulfate baths once a day for seven days had increased levels of magnesium in their blood and urine, suggesting that Epsom salt can pass through the skin and into the body’s cells and bloodstream.
If true, this could undergird a variety of medical benefits. Magnesium plays a role in a range of biological…
