Lately, I’ve been hearing a lot from patients and friends who are enthusiastically pursuing a “whole body cleanse” or “colon cleanse,” or a “detoxification cleanse.” And I’ve seen ads about these cleanses promising a number of health benefits, based on the general principle that every so often it’s a good idea to rid yourself of toxins that are undoubtedly accumulating within you.

Spring cleaning for your body? The idea goes back centuries. And sure, cleansing — or cleaning — is clear enough for bathing or mopping a floor. But how does a cleanse work in the human body? Do cleanses really deliver on their claims?

Let’s start with the name

Cleanses go by many names and descriptions, including:

• Colon cleansing, also called a “colonic” or “colonic irrigation.” Large amounts of water and other substances, such as coffee or herbs, are flushed through the colon via a tube placed into the rectum.
• Detoxification (or detox) diets with names like “Super Cleanse,” “Full Body Cleanse Express,” and “Antioxidant Cleanse.” These are specific, often restrictive diets that last a few days to a month and consist largely of liquified vegetables, fruit juices, and spices.
• Periodic fasting to take a break from your usual (and potentially harmful) diet, which is presumed to include an array of toxins, synthetic chemicals, and other poisons. Fasting is often a part of detox diets.

Does it make sense?

If you’ve seen the ads I’ve seen, it doesn’t just make sense — it seems like something we should all be doing regularly! Cleansing means cleaning and who doesn’t like clean?

But it’s not that simple. The normal intestinal tract is teeming with bacteria. While dietary changes, medications, and even exposure to other people (and pets!) can change your intestinal flora, scientific reality dictates that you can’t “cleanse” your body through diet or “detoxify” your colon. It’s not even clear what toxin or toxins a cleanse is supposed to remove, or whether this actually happens.

Advocates of cleanses would argue it makes intuitive sense. You’ll find plenty of testimonials from people who report feeling better in a number of ways (see below) after completing a cleanse. Predictably, the answer to whether a cleanse is a good idea depends on who you ask.

What the ads say

Claims vary by product, but ads often promise a cleanse will

• increase your energy level, focus, and sense of well-being
• help you lose weight
• improve circulation
• reduce inflammation (and as a result, relieve arthritis pain and suppress autoimmune disease)
• remove toxins from urine, stool, and sweat.

Some ads promise specifics, such as “strengthening the liver, blood, and colon.” What? There are claims about increased sex drive, better mood, and fewer cravings for junk food. According to the ads, the number of ways a cleanse can help seems endless.

What the evidence says

There’s a stark contrast between powerful claims made by those promoting various cleanses and the scant evidence that they do anything good for your health. Searching the medical literature for “detox diets” or “cleanse diets” yields almost no relevant, high-quality medical evidence demonstrating health benefits. For example:

• A lemon detox diet is often cited as evidence supporting detox diets to improve health. A single study found that overweight women following a very-low-calorie diet with “organic maple and palm syrups and lemon juice” reduced body fat and insulin resistance, and had lower levels of inflammation. However, the study was small, lasted only 11 days, and most of the positive changes were also observed among subjects on a similarly calorie-restricted diet without lemon juice.
• A review of detox diets for weight control and toxin elimination stated that “Although the detox industry is booming, there is very little clinical evidence to support the use of these diets.”
• A review of colonic cleanses concluded that “The practice of colonic cleansing to improve or promote general health is not supported in the published literature and cannot be recommended…”

Remember, health claims for cleanses have not been evaluated by the FDA. Read the product disclaimers before you buy and use these products!

Could a cleanse be potentially harmful?

Just as there is limited evidence of benefit associated with detox or cleanse programs, there is limited evidence of harm. However, there are reports of side effects and complications. Examples include:

And there’s also cost to consider; product costs are not covered by most health insurance. I found ads for detox diet programs charging $15 to more than $250. Some recommended repeating the program periodically, so the cost can be considerable.

The bottom line

I know there are many people who find intermittent detox diets or cleanses useful, and firmly believe they improve health. And the ads for these programs are filled with glowing testimonials. “It has been an awakening for me!” “I’ve never had this much energy! “Toxins were leaving my body through my pores and digestive system… better sleep, increased energy levels, and I lost weight.“ This one seemed directed at me: “I don’t care who says what about this detox, this stuff works!!! Day 12, no exercise, down 19 pounds!”

Still, given the lack of evidence supporting their use, the risks associated with their use (even if small), and their lack of regulation, it’s hard for me to be enthusiastic about the use of detox diets or cleanses. If you’re concerned about toxins in your body, I say choose a healthy diet and avoid pollution, pesticides, and other harmful substances as best you can. Leave the detoxification to the professionals: your kidneys, liver, and other self-cleaning organs of your body.