Oprah Winfrey does it -- and even blogs about it. As more celebrities jump on the detox bandwagon, it's also catching on with the general public. But some medical professionals say these body cleansing diets are not only unnecessary, they can be dangerous.

When done correctly, detox diets support the body's natural detoxification systems through food and lifestyle choices, said Dr. Michelle Schoffro Cook, a doctor of natural medicine and acupuncture and author of The 4-Week Ultimate Body Detox Plan.

Our bodies are always detoxifying, she said, but because we are dealing with more toxins in our food and environment than ever before, sometimes they need some assistance to get the job done. I'm just looking at supporting those systems so they can better do what they need to do, Schoffro Cook said, adding that detox diets can help the body handle toxic overload and result in improved mental clarity and increased energy.

But some medical professionals say that our bodies do a fine job of detoxing on their own, and that cleanses are unnecessary, and may be unhealthy. Detox programs are generally based on testimony with a scattering of science and an absence of clinical evidence, said Dr. Roger A. Clemens, a spokesperson for the Institute of Food Technologists. Our bodies take care of detox through our skin, our livers, our GI tract and our respiratory system, Clemens said. These organs and organ systems do a phenomenal job of removing toxins.

There are a variety of detox diets and kits available to consumers. The Master Cleanse, taken from a book first published in 1976 and often mentioned in connection with celebrity weight loss, is one well-known cleanse diet that involves consuming nothing but a mixture of lemon juice, maple syrup and cayenne pepper up to a dozen times a day for at least 10 days. Other books outline detox diets that focus on eating particular foods or taking herbal supplements. And in health food stores, customers can find several detox kits that use supplements to help the body eliminate toxins and improve functioning.

Different types of cleanses will target different body systems, Schoffro Cook said. Because you're working to eliminate toxins that can be interfering with virtually any biochemical process in the body, you can therefore experience just about any type of benefit, depending on what symptoms you're experiencing from toxicity. She has seen people recover from arthritis and fibromyalgia in her clinical practice, she said, after following her diet-based detox plan, and others have recovered from illnesses more quickly or effectively than they otherwise would have.

Schoffro Cook and Clemens agree that cleanses are not safe for everyone. We believe there are a number of people who are at risk with these kinds of regimens, Clemens said. Women who are lactating, pregnant or hoping to become pregnant should avoid detox programs, and they shouldn't be used by children and the elderly or people who are ill or recovering from surgery.

Schoffro Cook also cautions against many of the detox kits that are commercially available. Many make one-size-fits-all claims, she said, when a more individualized approach is needed.

Detox diets also vary in their benefits and healthfulness, Schoffro Cook said. In my experience, I've come across many that are actually quite damaging to a person. Water diets, fasts and detoxes that prescribe eating only one food for several days at a time are some examples, she said. Clemens cautioned that many detox diets lack adequate nutrition because of their restrictive nature, and that neither the Food and Drug Administration nor the Federal Trade Commission has the available resources required to adequately monitor detox diets and preparations and the health claims they make.

It's important to realize that detox shouldn't be an unpleasant process, Schoffro Cook said. Symptoms like nausea, headaches and diarrhea can result from a cleanse that is too strong or being done incorrectly, she said.

I think a lot of people wrongly attribute incorrect detoxification to something they call a 'healing crisis', she said. Proponents of these types of harsh detox programs often lead consumers to believe that a healing crisis is a beneficial thing, when in fact it may just mean that you're overburdening your body and detoxifying too quickly or incorrectly.

Detox skeptics should try a healthy one for themselves under expert supervision, Schoffro Cook said. Most people will experience profound improvements.

Part of the appeal of detoxes is the idea that we can abuse our bodies for years with poor habits and then eliminate the damage in a short period of time, Clemens said. What appeals to the general public? A quick fix.

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