A new product called the infrared sauna may be the next health craze, especially because manufacturers say that using it can burn 600 calories in 30 minutes, relieve any number of ailments, improve mood and even reverse aging.

But doctors say consumers should proceed with caution, or just take a hot bath.

“Dry” saunas use infrared heat instead of steam. Marketers and manufacturers say they provide numerous health benefits, and can even bring relief from serious illnesses.

Physicians and researchers say reports that infrared saunas produce more benefits than a conventional sauna, hot tub or heat lamp are at best suspicious, and maybe even false.

“This is just a plain lie,” said Dr. James Shoemaker, director of the Metabolic Screening Laboratory at St. Louis University School of Medicine. “Infrared is just heat. Heat is heat. Heat penetrates, but it’s nothing exotic.

“A warm bath would do everything that they are claiming this does. A warm bath makes people feel comfortable, doctors recommend it, it’s good for muscle strains and sprains, people use warm baths in rehab. … They’re just selling it in a new and different way.”

Dr. Richard Moore, who owns the Lifestyle Fitness Center, a holistic practice in Clayton, reflected the responses of other physicians in the area. He’s skeptical that any sauna could relieve so many illnesses.

“It doesn’t seem to make sense,” Moore said. “I’d like to see some science behind it.”

However, the physicians said that, in general, the only danger from infrared saunas_as with any heat-based therapy_is dehydration. Otherwise, medical professionals don’t fear infrared heat; in fact, hospitals still use it for infant care in nurseries.

About saunas

Saunas have been around since prerecorded history. People sit, relax and sweat. Saunas can be found in well-equipped health clubs and private homes.

The infrared sauna uses infrared radiation to produce heat. Don’t let the word “radiation” frighten you; for our purposes, here’s an elementary explanation:

There are three basic types of radiation on the light spectrum.

Visible light is in the middle. That exists as the colors we see.

To the right of visible light is the dangerous ionizing radiation: the ultraviolet forms that cause sunburn or cancer.

To the left of visible light is safer nonionizing radiation: infrared, microwave, radio signals and so forth.

If you’ve stayed in a hotel room and been warmed by a bathroom heater in the ceiling, you were probably under an infrared heater.

Most infrared saunas on the market are small, wooden rooms that can hold one to four people. The infrared heat lamps_four to six in a sauna_are recessed in the box. Temperature is regulated by digital controls similar to a household thermostat.

People who use infrared saunas say they sweat more than inside a conventional sauna, which is heated by electric heating elements and steam.

The quality and volume of that sweat is key to the health benefits, manufacturers say.

What proponents say

The infrared radiation penetrates the skin and produces chemical reactions that make the fat cells expel poisons_toxins_that cause or aggravate illnesses over a lifetime, they say. Sweat then carries the poisons from the body.

This detoxification process helps rid the body of heavy metals and other environmental toxins they say are stored in fat cells_mercury, lead, cadmium, tobacco, pesticides and other nasties. The increased sweat extracted by the infrared heat includes 15 to 20 percent more toxins than conventional sweat, proponents say.

Meanwhile, the infrared sauna increases metabolism so the cells burn more calories-more so than a vigorous workout-over 30 minutes, they say.

Their conclusion: Avid users of the infrared sauna will improve their health without using drugs and lose weight without increasing exercise.

What physicians and researchers say

Infrared radiation heats surfaces, including skin, just like any other heating tool.

“There’s only one way to break down fat cells with heat,” said Shoemaker. “Set the person on fire. Heating people up does not remove any (toxins) from their bodies.”

After reading data published by a manufacturers, Shoemaker said manufacturers “should tell the whole truth: Saunas feel good, they make you warmer. Like anything that makes you warmer, especially while lying comfortably, the sauna can make you sweat and relax, lower your pulse and blood pressure by making blood vessels dilate, and remove salts from your system. Why claim anything more?”

Shoemaker’s laboratory at St. Louis University uses radiation to help identify substances in body fluids. Sweat doesn’t carry heavy metals from the system, he said.

Dr. Mark Mengel, head of the Community and Family Medicine program at St. Louis University School of Medicine, also says he’s skeptical that an infrared sauna can pull heavy metals out of the system and cause weight loss. If some sort of heavy metal causes a problem, doctors administer a substance that binds with the metal and the system excretes it, he said.

To lose weight, muscles must move and people must take in fewer calories than they burn through exercise. There’s no way to reduce fat by sitting under a heat lamp, infrared or otherwise, the doctors said.

While area physicians and researchers asked for more science on the manufacturers’ statements, no comprehensive study was available from the National Institutes of Health or other sanctioning bodies.

Two studies in Japan were published in the Journal of the American College of Cardiologists. They examined the effects of infrared saunas on a total of 45 people. Neither article said who funded the studies.

One doctor who studied 25 subjects said he found many benefits, including weight loss, improved blood pressure, improved circulation and improved blood chemistry. A second study said the saunas improved heart function.

On the rise

Popularity of the infrared saunas seems to be growing.

Sunlight Saunas in Lenexa, Kan., is one of many manufacturers of infrared saunas, says its business is booming. A company spokesman says one of its units is used commercially in St. Louis and hundreds have been sold to individuals in St. Louis.

The company wouldn’t give exact figures. However, Entrepreneur magazine recently selected the company for its Hot 100 list for 2004. To make the list, a company had to be less than five years old, be owned by the founder, and have more than $1 million in sales in 2003.

Sunlight Saunas units run from about $1,500 to $5,000. Prices for units by other manufacturers are in the same range; you can find them on the Internet.

Consumers’ stories

Kathleen H. Christ, owner of St. Louis Aquatic Center in Creve Coeur, owns a unit manufactured by Sunlight Sauna. Her nonprofit business uses natural healing and water therapy services to help people. She’s also a massage therapist and delivers a range of holistic therapeutic services.

Christ became interested in the saunas after reading literature about detoxification. Relatives and friends of hers in the military, who have returned from battle zones as long ago as Vietnam and as recently as Iraq, were in need of relief from poisons they’d picked up overseas, she says-poisons ranging from the mercury in Agent Orange to plutonium.

Her two-person sauna arrived in March. She enthusiastically talks about good results_increased energy, better skin tone and generally feeling healthier_for herself and for others using the sauna.

She said she has not seen significant weight loss among her clients, but notes that she has lost five pounds since she started using it in March.

“But that can be from increased energy,” she said. “I’m not ready to say that this results in weight loss; I don’t want people running out and buying these for cosmetic purposes.”

Before her clients use the sauna, she has them fill out questionnaires to determine their health status. Users should be aware that heat therapy can open blood vessels and affect the pulse rate and blood pressure.

Also, Christ weighs her clients before and after they use the sauna. The sweating causes a drastic drop in water weight-sometimes more than two pounds in less than an hour.

After a session, Christ makes her clients drink an equivalent amount of water to match what they lost in sweat. She also gives them a supplement to replace electrolytes lost in sweat, she says.

Christ says she has no means to test to see if clients are expelling toxins. Their improved energy has been the only way to gauge that, she said.

One of Christ’s clients, Ruth Schmidt of Webster Groves, said her husband, Robert Schmidt, 78, suffered a second-degree burn from a heating pad. The wound wouldn’t heal, she said.

After two weeks in the sauna, “It healed in a matter of two weeks,” she said. Also, she had arthritis in her hands and the sauna greatly relieved the pain.

Another client, Donna Becher of St. Charles, said using the sauna has helped shrink wrinkles and get rid of some poison ivy scars that wouldn’t go away. In addition, using the sauna has made her more energetic and cheerful, she says.

In general, using a commercial infrared sauna costs about $30 for one-half hour. Experts suggest that people take all of the same precautions against dehydration and overheating as they would when using any sauna or a hot tub.

Skepticism

Shoemaker, who has tried the infrared sauna, said, “People can burn up their body fat through exercise. (Exercise) does actually release things that are stored in their body. That’s true. But you can’t do it by heating people up; that’s just silly.

“They’re playing on the fear of the public. The main toxin people have in their bodies is alcohol. They drink it, and they like it. And then tobacco. It’s just silly to say these other things are worse when people willingly put alcohol and tobacco in their bodies.”