When Ryan Pierce went on a juice fast, he was looking for a quick remedy. The former KU student says he’d spent too long destroying his body and needed a way to rebuild it. He smoked cigarettes, drank several times a week and never paid much attention to his diet. He wanted to detoxify his system and, as a full-time student with a part-time job, he needed a method that didn’t require a lot of time.

Nine days on nothing but water and all-natural juice did the job. Pierce had to remain as inactive as possible to conserve energy, he says, but during the fast he began to feel better. He could breathe more easily and, in general, he just felt healthier — cleaner.

Although weight loss wasn’t Pierce’s purpose for fasting, he did lose 10 pounds in the nine days he didn’t eat. The weight loss didn’t stick — he gained back the pounds soon after returning to solid food. What did stay with Pierce after his fast, though, was a sense of how to better care for himself. Now, almost two years after his nine-day detox, he has quit smoking and eats healthier than he did before.

Both the physical and spiritual benefits of fasting have long been recognized. Despite these advantages, fasting requires caution and isn’t for everyone.

Fasting cleanses the body by increasing the processes that release toxins from the colon, kidneys, bladder, lungs, sinuses and skin, says Elson Haas, author of Staying Healthy with Nutrition: The Complete Guide to Diet and Nutritional Medicine. Fasting also allows many of the body’s systems a chance to rest. Haas believes that much disease is due to “biochemical suffocation,” which occurs when cells don’t adequately eliminate their wastes. Fasting, he says, allows each cell the opportunity to catch up on its work of eliminating these toxins.

“Fasting is like turning off and cleaning a complex and valuable machine so that it will function better and longer,” he says.

True fasting is the avoidance of all food and drink, and the next-strictest form allows only water. The most common fast, however, allows both water and juice. Haas usually recommends this juice fast rather than other kinds, he says, because it’s safer and easier to maintain. Juice provides calories and nutrients, which support the body nutritionally and enable it to recover more quickly after the fast.

A person should work up to longer fasts by first going on ones that last only one or two days, Haas says. It is also important, he says, to come off of solid foods gradually in the days before the fast and to reintroduce them into the diet equally slowly in the days that follow it. In order for the fast to cleanse the body as much as possible, it’s vital that the juices be free of preservatives.

Preservatives may not be as much of an issue, though, if a person is fasting for spiritual purposes. Elmer Towns, author of Fasting for Spiritual Breakthrough, doesn’t mind drinking juice with preservatives when he fasts.

“I don’t get upset about additives because I believe God looks at the heart,” he says. “He doesn’t look at what goes into the mouth.”

Spiritual fasts should always be accompanied by prayer, Towns says. The purpose of going without food is not to impress God, he says, but rather to take prayer to a higher level and to demonstrate sincerity.

Spiritual fasts can have physical benefits, as well, even if those benefits are not their main purpose. Towns says that when he had a check-up during a 40-day fast, the doctor told him he was in better health than anyone he’d ever seen. Fasting for such a long time made him weak, Towns says, but also healthier.

Like Towns, Chris Carter fasts for spiritual reasons. The Kansas City, Kan., junior says he has fasted during difficult times as a way of calling on God for help. At other times, he’s done it as a reminder to himself of the people in the world who experience hunger on a regular basis.

Most of his fasts are only a day long, Carter says, and he usually drinks only water during them. He says these one-day fasts aren’t too difficult, and that most of the time they leave him feeling cleaner inside. The four-to-six-day fasts he’s done made him feel weak and sleepy, but not necessarily hungry. Carter says during some of his longer fasts — especially those in which he’s gone without both food and water — one of the most distinctive things he’s felt has been the sensation of his blood thinning.

“It feels kind of like your foot falling asleep,” he says.

Haas warns that not everyone is a good candidate for long fasts. If fasting is overused, it can lead to nutritional deficits and lowered immunity rather than having a positive, cleansing effect. He adds that some people, including those who are underweight, pregnant or who have serious health problems, should not fast at all.

Haas emphasizes, however, that if a person meets the physical requirements and takes the proper precautions, abstaining from food can be incredibly healthy.

“From a medical point of view, I believe that fasting is not utilized often enough,” he says. “We go on vacations from work to relax, recharge and to gain new perspectives on our life — why not take occasional breaks from food?”

WHERE TO FIND FASTING- FRIENDLY FARE

The Community Mercantile

901 Iowa St.

The Merc carries organic juices.

The Underground

Sells Odwalla juices.

Juice Stop

812 Massachusetts St.

4821 W. Sixth St.

3514 Clinton Pkwy.

Juice Stop makes drinks with all-natural juices, and offers a protein booster option.

Freshens Smoothie Company at the Kansas Union

Sells blended smoothies.