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"Detox Diets" and Prolonged Fasting Can Be Toxic to Your Health

Jul 26, 2010 | Updated May 25, 2011

Recently, Ashton Kutcher announced on Twitter that he was undertaking the Master Cleanse: a fast lasting up to 10 days with nothing on the menu but a cocktail of water, lemon juice, maple syrup and cayenne pepper - with some salt water and laxatives for good measure. Thus, he has joined some other celebrities as well as countless other individuals in a misguided attempt to remove a variety of "toxins" from their bodies. And the Master Cleanse, or Lemonade Diet, isn't the only "detox" ritual out there. Scores of regimens, spa treatments, juices, colonic irrigation, vitamins and herbal pills promise to make you feel "rejuvenated," younger and thinner by ridding your body of "toxins."

Here is the theory behind this and other "detox" diets: our bodies are exposed to a variety of toxins from smoking (including secondhand smoke), air pollution, caffeine, pesticides, artificial sweeteners, sugar and alcohol, to name a few, and these "toxins" build up in our bodies and cause fatigue, headaches and chronic diseases. These diets not only rid the gastrointestinal tract and liver cells of these "toxins," but also allow them to rejuvenate in order to wage a better battle against future "toxins." Unfortunately, the theory is just not supported by any facts; not surprising, since the whole scenario is a made up hypothesis developed more than 40 years ago when the Master Cleanse diet first appeared.

In fact, the body is really pretty good at eliminating toxins on its own. The liver is capable of inactivating many environmental toxins and excreting them through the stools or via the kidneys into the urine within hours of exposure. Also, for acute insults like eating rotten food, the gastrointestinal tract may get into the picture directly via vomiting and diarrhea. If you feel like your liver or other organs need a break, by all means give them one. Don't take these toxic substances into your body in the first place. Give up smoking. Consume less caffeine and carbonated beverages. Drink water instead of alcohol. It's not nearly as glamorous, but it's effective.

Fasting has a long tradition as part of religious ritual in many different faiths (e.g. Lent, Ramadan, Yom Kippur). But these fasts are either partial - allowing for food at certain times of day - or for relatively short periods of time. Spiritual fasts are not the problem. Using extreme fasting as a tool for "detox" regimens or for dieting does concern me, especially fasts that are supposed to last for 10 days or more. These are often inspired by faulty theories as discussed above or by poor body image or late-night infomercials for products making claims that are unsupported by science.

There are several problems associated with prolonged fasting. Such deprivation may lead to loss of vitamins, minerals and electrolytes. Weight loss will occur because of caloric deprivation, but the weight will be regained when the fast is finished. Much of the early weight reduction is due to loss of salt and water. And with protein-poor diets like the Master Cleanse, muscle, and not fat, is broken down initially. Thus, these diets are associated with electrolyte imbalance, nutritional deficiencies, weakness and difficulties concentrating, to name a few of their problems. These diets would be stressful for anybody, but are potentially dangerous for individuals with diabetes, heart disease, or pregnant or breast feeding women, children and teenagers, who need well-balanced meals for optimum health and growth.

The other area of "cleansing" interest to detox fans is the cleansing of the digestive tract through colon irrigation or laxatives. The use of laxatives as part of diet regimen is alarming, as it is a common symptom of eating disorders and is a great way to develop severe electrolyte imbalance because of loss of potassium in the stools. The colon doesn't really need the assistance of irrigation. The bacteria that occur naturally in the digestive tract detoxify food, and the mucus membranes that line the colon prevent those discarded substances from reentering the blood and tissues. The colon also cleanses itself, shedding old cells about every three days so material doesn't build up. As is true for the "detox" diets, colonic cleansing for general health promotion is not supported by the published scientific literature, and does carry risks such as perforation of the colon or rectum, electrolyte imbalance and infection.

What you put in your body will have a much greater impact on your colon health than what you flush through it. Upping fiber intake can help, and most Americans aren't taking in enough of it. Current recommendations are 25 and 38 grams of fiber for women and men under age 50, respectively, and 21 and 30 grams for women and men over age 50, respectively.

Gulping coconut juice or other fresh fruit juices is certainly fine as part of a balanced food plan. But any plan suggesting a healthy person must forgo healthy sources of nutrition for extended period of time or irrigate their colon should be viewed as a toxic suggestion.