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Detox Diets & Cleansing: Facts & Fallacies

diagram shows a highlighted human colon in a person's body
Studies are showing that flushing the colon (or large intestine) with herbs and water is not only useless but may be detrimental to a person's health. (Image credit: <a href=""> Sebastian Kaulitzki</a> | <a href="">Shutterstock</a>)

From juice fasts to colon cleanses, detox diets and purges are all the rage with those looking to lose weight or kick start a healthy lifestyle. But these therapies aren't as healthful as they may seem, according to doctors and nutrition experts. 

Detoxification, or the practice of ridding the body of toxic or harmful substances, is promoted on countless websites and endorsed by a host of celebrities. Advocates of detox therapies start with the premise that the body accumulates toxins that can cause cancer and other diseases. Regularly cleansing oneself of such toxins purportedly reduces the risk of disease and endows one with a feeling of good health, more radiant skin and having more energy. 

However, there is no scientific evidence that any of these so-called cleanses really benefit a person's health, according to Stella L. Volpe, professor and chair of the department of nutrition sciences at Drexel University in Philadelphia. 

"Our livers and kidneys, if healthy, do a great job of cleansing our bodies on a daily basis," Volpe told Live Science. "Increasing fruit and vegetable intake, whole grain intake and drinking more water over sweetened beverages would go a lot farther to improve someone’s health over the long-term than a 'cleanse.'"

It should be noted that the detoxification described here is different from the practice used in substance abuse treatment. Detoxification in that context is "the process of allowing the body to rid itself of a drug while managing the symptoms of withdrawal," according to the National Institute on Drug Abuse. This kind of supervised detoxification may prevent potentially life-threatening complications that might appear if the patient was left untreated. 

The truth about toxins

A toxin is a poison produced through biological processes. The nicotine found inside of tobacco leaves is a toxin; so is the metabolic waste produced by cells inside the human body. But when people talk about "toxins," they're likely referring to manmade chemicals as well. 

Your body can accumulate both natural and manmade toxins when you ingest food and water and when you breathe. Air pollutants like ozone and nitrogen dioxide have been linked to a range of health problems in humans — from respiratory inflammation to cancer, according to the Environmental Protection Agency. Pollutants in water include arsenic, a known carcinogen, and mercury, which is linked to nervous system disorders, according to the U.S. Geological Survey (USGS). Even organic fruits and vegetables aren't safe from toxins such as E. coli and salmonella, which can cause acute illness, according to the Royal Society of Chemistry

However, drinking a juice or undergoing an internal cleanse isn't going to help your body get rid of these toxins any faster or more effectively, according to Dr. Michael Gershon, a professor of pathology and cell biology at Columbia University in New York. The body is well equipped to get rid of toxins all on its own, Gershon told Live Science.

The liver is the body's main defense against toxins. (Image credit: Nerthuz (opens in new tab) Shutterstock (opens in new tab))

Built-in detox system

The main organ that helps in the detoxification process is the liver. Everything you breathe or swallow that is broken down and absorbed into the bloodstream passes through the liver, which is the largest internal organ. The body depends on the liver to regulate, synthesize, store and secrete many important proteins and nutrients and also to purify, transform and clear toxic or unneeded substances, according to the German Institute for Quality and Efficiency in Health Care.

Many detoxification products claim to "cleanse" the liver, but in healthy individuals, the liver is not a place where toxins are stored. Rather, the liver turns potentially harmful chemicals into water-soluble chemicals that can be sweated or excreted from the body. 

The liver typically does a "superb job" of detoxing your body, Gershon said. However, there are a few exceptions to this rule. People with certain liver conditions — such as viral hepatitis (Hep A, B or C) or alcohol-induced liver disease — may not have healthy livers, and toxic substances can sometimes accumulate in their bodies. Certain substances that can be toxic in high doses, like vitamin A, iron and copper, can also accumulate in the liver or other organs as a result of disease. But there is no scientific evidence that detox diets or liver cleanses help treat liver disease. 

Some advocates of liver cleansing argue that so-called liver cleansers help the liver function better to remove toxins. There are no convincing studies to support such claims, although some studies support the notion that certain foods and herbal supplements may promote liver health. [Related: Saucy Science: How to Flush Out a Hangover]

Meet the colon

In addition to cleanses and special diets for the liver, some advocates of detox therapies also promote so-called colon cleanses. But these therapies — which include enemas and colonics, as well as laxatives and herbal remedies — are not medically useful, according to the Mayo Clinic. In 2011, researchers at Georgetown University conducted a comprehensive review of the medical literature and found absolutely no scientific support of the practice of detoxifying the colon. In fact, colon cleanses can do more harm than good, according to Gershon.

"The colon houses many of the microbes that call us home. They are our friends and keep us safe. When we upset our microbes — as with antibiotics — bad bacteria, such as Clostridium difficile [the bacteria behind infectious diarrhea], can move in and cause disease," Gershon said. 

The most common side effects from colon cleanses are nausea, vomiting, diarrhea and abdominal pain, according to the Mayo Clinic. Depending on the cleansing solution and amount of water used, patients can experience a dramatic loss of electrolytes. Case reports document serious medical conditions, such as kidney and liver failure, air emboli, rectal perforations, blood infections and death from dysentery.

Meet the fat cell

A third, general detoxification scheme is done with fasting, juicing, swallowing an herbal solution or eating a raw diet.

However, studies have not shown that particular foods or herbs are effective at pulling toxins from the blood or organs. Some proponents of these detox therapies argue that fasting or juicing will help burn fat cells, which they say contain toxins. But this idea is not a scientifically sound argument, according to Gershon, who said that burning fat cells is not related to the body's natural process of detoxification. 

Dramatically limiting food intake through fasting or extreme dieting can also put a lot of stress on a person's bodily systems, according to both Volpe and Gershon. Dehydration is one serious risk for those who are fasting, Volpe said. 

"In most cases, the liver, kidney and intestine are so good that they can overcome even the stupidity of the worst dietary insults," Gershon said. "Juicing and cleansing, however, push the system in an extreme way. They are dangerous even if most people survive. But why take a risk for no gain?"

Follow Elizabeth Palermo @techEpalermo. Follow Live Science @livescience, Facebook & Google+.

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Elizabeth Palermo
Elizabeth Palermo
Elizabeth is a Live Science associate editor who writes about science and technology. She graduated with a bachelor of arts degree from George Washington University. Elizabeth has traveled throughout the Americas, studying political systems and indigenous cultures and teaching English to students of all ages.