The Truth About Detox Diets

Medically Reviewed

If you spend time online, read lifestyle magazines, sit through infomercials, or watch celebrity interviews, chances are you’ve seen something about “detoxing.”

That refers to various dietary regimens, products, and procedures that are supposed to cleanse your body and give it a radical reboot. Those range from numerous herbal supplements and tonics, one-day fasts, and special diets (some promoted by celebrities like Beyonce and Gwyneth Paltrow) to techniques as dramatic as coffee enemas and other “colon cleanses.”

The idea of cleaning yourself out as a way of kick-starting healthier habits may sound appealing, especially if you’ve been eating poorly, overindulging during the holidays, or otherwise treating your body less than optimally. But there’s no evidence to back the detox concept—and it makes no scientific sense anyway.

Some of the plans are outright dangerous, especially for certain groups of people. Here’s a question-and-answer primer on the detox trend and why, as with so many other things in health (and life), it isn’t the quick fix it’s claimed to be.

What does detox mean anyway?

For decades the term detox (short for detoxification) was used almost exclusively to refer to medical procedures that rid the body of dangerous levels of poisons or, more commonly, to programs (often hospital-based) that help people addicted to alcohol or drugs kick the habit and cope with the sometimes-agonizing withdrawal symptoms.

Today detox has become a catch-all name for a wide variety of nontraditional diets, fasts, spa treatments, and other products and procedures that, proponents claim, will help you reset your metabolism, drop weight fast, clean out your gastrointestinal tract, and eliminate “toxins” from the body.

Among the best known and most extreme is the Master Cleanse, which calls for consuming nothing but warm saltwater, laxative tea, and a liquid concoction of lemon juice, maple syrup, and cayenne pepper for 10 days.

There are many other plans and books, from the 10-Day Green Smoothie Cleanse and Dr. Oz’s 3-Day Detox Cleanse (“All you need is 3 days, a blender and $16 a day!”) to the Martha’s Vineyard Diet Detox, which promises a startling (and definitely unsafe) 21-pound weight loss in 21 days.

And a quick Internet search or visit to the supplement aisle of health-food stores and drugstores will turn up many juice cleanses, some with hefty price tags. A 5-Day Juice Cleanse sold on the Williams-Sonoma website, for example, costs $330 (before shipping and handling) and includes juices with names like D-Tox and The Master.

What are these ‘toxins’?

Toxins are usually defined as substances created by plants, animals, and microorganisms that are poisonous to humans and other animals at relatively low doses. The definition is sometimes expanded to include other dangerous substances, regardless of origin or dose needed to cause harm.

Among detox proponents, however, the definition of toxins has been so broadened as to be essentially meaningless.

For example, detox plans often refer to refined sugar, caffeine, red meat, alcohol, gluten, and countless environmental contaminants as toxins. And they cite conditions as varied as headaches, obesity, fatigue, poor memory, acne, various cancers, gastrointestinal problems, depression, insomnia, arthritis, and chronic nasal congestion as evidence of “toxicity” wreaking havoc in the body, though there is no research to support any of this.

Much detox lore is focused specifically on the colon: Toxic substances supposedly attach to and fester in the colon’s lining, increasing the risk of illness unless they’re removed via a special diet or, in some cases, colonic cleansing. Such notions are false—and absurd.

The idea that stagnation and decay in the colon (large intestine) produce toxins that poison the body is an ancient one, sometimes called auto-intoxication. Down through the ages, people have used strong laxatives, enemas, and other colon “cleansing” or “irrigation” practices as cures for almost every medical complaint as well as for spiritual benefits. But these ideas and practices were discredited long ago.

Still, the fear of auto-intoxication seems real to some people, which often leads them to the weird world of colonic irrigation (also known as hydrotherapy).

It involves inserting a tube into the rectum and up into the colon and pumping in large quantities of water—usually containing additives such as soapsuds, herbs, coffee or coffee grounds, and other potentially irritating substances—in successive doses or continuously. This is very different from a standard enema.

Don’t our organs ‘detox’ us?

The human body is a marvelously efficient detoxing machine when it comes to self-cleansing and protection from chemical damage.

The skin, airways, and intestines act as barriers to most harmful substances. The liver is the body’s primary processor, converting dangerous substances into less harmful ones that are then eliminated via urine and stool, unless overwhelmed by a large dose of a poison.

The kidneys also filter out unwanted compounds directly into the urine. Unless impaired by certain illnesses, these organs cleanse themselves.

Healthful eating, adequate sleep, and exercise help the body to run optimally. There’s no evidence that a special detox diet or fast can improve what your own body is naturally programmed to do. These detox schemes may, in fact, impair the body’s natural detox mechanisms.

What about detoxing to lose weight?

If your goal is weight loss—a benefit touted by most of these plans—detoxing is not the solution.

While the severe calorie restriction that most detox plans encourage can make you lose weight rapidly, as can the diuretics or laxatives they may include, most of the pounds lost are from water or the accelerated elimination of fecal matter, not body fat or toxic material.

Pounds lost by fasting or dramatically cutting calories almost always return when normal eating habits are resumed.

Are detox diets or cleanses dangerous?

They can be, especially the more extreme or restrictive regimens. For instance, some plans eliminate essential nutrients, which could lead to malnutrition if you detox often. They can disrupt the balance of intestinal microorganisms, leading to the overgrowth of less desirable types.

A prolonged juice cleanse (also called a juice fast) or even excessive water intake (as some plans call for) can lead to a dangerous imbalance of electrolytes, such as sodium and potassium, in the blood.

Detoxing practices that involve laxatives, enemas, and colonic irrigation are especially risky. It is not true that your colon is clogged with toxic fecal matter that you can’t get rid of except by enemas or irrigation. Fecal matter is not rife with toxins; it is indeed populated by microorganisms, many of which are actually beneficial.

Colonic irrigation can cause not only diarrhea, dehydration, and impaired bowel function but also serious complications such as electrolyte imbalances, blood infections (septicemia, caused by contaminated equipment), perforation of the intestinal wall, severe hemorrhage, and even heart failure.

Some people are at special risk from extreme eating plans in general, including pregnant women, children, and those with a weakened immune system or chronic conditions such as heart or kidney disease. They, in particular, should avoid any type of cleanse, purge, prolonged fast, or otherwise very restrictive diet.

Our advice. Detox plans and colonic cleanses are at best unnecessary and at worst harmful, even deadly.

Eating a healthy diet, getting enough sleep, avoiding tobacco smoke, limiting alcohol, and exercising regularly should keep your body’s “cleansing” systems functioning well—and confer the results claimed for detox plans.

Read more about the safe way to lose weight.