Less than a year ago, Stacy Boston-Svarczkopf ate fast foods and high-fat meals. She drank lots of coffee. She was plagued by rashes on her elbows and the back of her head.

In January, she changed her lifestyle. Now she’s on a diet filled with whole grains, fresh vegetables and fruits. She drinks herbal teas.

Boston-Svarczkopf, 39, switched after consulting with Jennifer Workman, a registered dietitian in Boulder, Colo. She suggested the rashes might be caused by a food allergy and recommended an “herbal cleanse” followed by a healthier diet.

The short-term cleansing diet helps rid the body of mucus, excess bacteria, undigested food, pollutants and other “toxins,” or impurities, Workman says.

“Changing my lifestyle cured my rash, and doing the cleanse was part of it,” Boston-Svarczkopf says.

For three days in January, Boston-Svarczkopf eschewed solid foods except for some steamed vegetables in the evening. She drank pureed organic vegetables for lunch and vegetable broth for dinner, according to Workman’s recommendations. She also drank rice protein shakes, liquid chlorophyll, aloe vera juice and herbal tinctures. She had massages, which are said to help loosen “toxins” from the deep muscle tissue.

“I felt energetic and clear,” she says. “It was kind of profound.”

Holistic practitioners say doing herbal cleanses several times a year helps remove impurities brought into the body by refined foods, pollution and pesticides.

“Everything gets stagnant,” says Workman, the author of “Stop Your Cravings: A Balanced Approach to Burning Fat, Increasing Energy, and Reducing Stress” (Free Press, $25). “It’s like a lake that’s not moving. It gets full of poisons.”

Proponents also say it clears mucus in the digestive tract, which in large amounts diminishes nutrient absorption. And they say it gives the digestive system a rest from digesting solid foods.

Those who have been through herbal cleanses say they feel increased energy, greater alertness and improved moods after a cleanse. They say it reduces the chance of getting illnesses such as colds and allergies and that it’s necessary to move toxins that get stuck in the body system.

Others question whether the process is really effective.

“I don’t think we have enough information to know whether they are good, bad or indifferent,” says Bonnie Jortberg, a nutritionist at the University of Colorado Health Sciences Center in Denver.

Cleanses last from one day to several weeks, depending on the method. They cost from several hundred dollars for herbal products for a three-day cleanse, to thousands for longer cleanses.

Cleansing therapies

Colon: Eat oat or wheat bran, ground flaxseeds, beans and vegetables for fiber. To break up gas, try ginger, flaxseed and probiotics.

Skin: Brush with a stiff-bristled brush for five minutes before a shower to stimulate blood circulation and remove dead skin. Hot baths, saunas and massages also help remove impurities.

Kidneys: Use natural diuretics such as dandelion or parsley or cleansing teas such as chamomile, rosemary or rose hip.

Liver: Dandelion, burdock and Oregon grape root are suggested for cleansing. Milk thistle seed or extract rebuilds damaged liver tissues.

Lungs: Exercise during a cleanse and take yoga classes to clear the lungs.