By now, you've undoubtedly come across Internet ads or social media influencers trying to sell you on a mystical detox tea or some panacea juice cleanse. When you look past the prepossessing supermodels and celebrities that front these nonsensical fads, you'll be unlikely to find much reliable research or scientific evidence backing their efficacy.
If anything, science seems to dispute the proposed merits of a detox diet or juice cleanse. "Detoxifying the body" is highly contextual; what are you trying to eliminate? Alcohol metabolites? Heavy metals? Phthalate plasticizers?
Herein lies the problem: Most people have no idea what makes something toxic, nor do they understand how the body detoxifies itself. So, if you want the truth about how to detox your body, or if that's even necessary, this article is for you.
In scientific contexts, detoxification refers to the elimination of noxious substances from the body. However, the term "detoxification" has been assigned colloquial definitions that make it quite vague if you're perusing the web for a "detox diet" or "3-day cleanse." As such, "detox" and "cleanse" are interchangeable terms in most health contexts.
It's safe to say much of the general public associates detoxification with "flushing toxins out of the body" or "cleansing the system."
Well, what makes something toxic? Is it the chemical itself?
Nope. It's the amount you're exposed to that determines toxicity. Detox-diet zealots ultimately insist that all synthetic chemicals leave the body in a toxic state — a shortsighted notion when you consider that the dose makes the poison.
Water can be toxic if you drink enough. So can sugar, sodium, vitamin D, iron, the list goes on. Things that most would classify as "healthy" and "good for us" can absolutely be toxic in high enough amounts.
Likewise, chemicals that we generally associate with toxicity, like carbon monoxide and mercury, have no adverse health effects at low levels of exposure. In fact, your body has both of those chemicals in it right now — just not in high enough concentrations to cause harmful outcomes (1, 2).
These examples tell us that a substance in and of itself isn't always necessarily toxic or harmful. The human body is dynamic and adaptive; very few biological processes are as black-and-white as detox diets and juice cleanses suggest.
According to the U.S. National Library of Medicine, "Toxins are substances created by plants and animals that are poisonous to humans. Toxins also include some medicines that are helpful in small doses, but poisonous in large amounts."
Furthermore, the term "toxicant" refers to a man-made poison found in the environment (usually as a pollutant in groundwater or the air). Note that toxins and toxicants cover a spectrum of substances, and unnatural chemicals are not inherently harmful. Sure, ingesting pesticide residues or lead from tap water is not likely to better your health, but in small amounts, it won't harm you either.
As the adage goes, "The difference between medicine and poison is in the dose." People need to understand that all chemicals/substances are safe in one amount and dangerous in another.
However, most cleanse advocates consider a toxin to be any substance "thought to be" harmful. These typically include heavy metals (like lead), preservatives, food additives and dyes, artificial sweeteners, xenobiotics, and other synthetic chemicals.
But here's the kicker: a 2005 publication in The Lancet Infectious Diseases found that not a single company endorsing detox diets or juice cleanses could provide any form of evidence for their efficacy (3). Even worse, the companies failed to identify a single toxin targeted by their products; they couldn't even reach a consensus on what the word "detox" means.
How could a researcher or scientist ever formulate a dietary product if they have no clue what substance they're "detoxifying"? It's a clear sign that detox diets and juice cleanses are based on senseless conjecture.
Not surprisingly, every detox diet you come across will prescribe an overly restrictive clean-eating meal plan; in some cases, they tell you to consume nothing but fruit juice or "superfood" smoothies for upwards of a month. (And of course, their detox diet will only work if you drink the associated "juice cleanse" concoction they conveniently sell).
A detox diet and cleanse may have subtle distinctions, but no specific protocol is worth detailing; eventually, they all fade from the spotlight for the next fad diet in queue (rightfully so).
The health and fitness realm is rife with ambiguity, especially if you search for information on detoxes. Many 3-day cleanse diets, for example, promise to "detoxify" your body and help you lose weight rapidly. Yet, there is virtually no data backing detox diets or juice cleanses.
According to a recent review, studies on cleanses are underwhelming (to say the least), as they suffer from "...small sample sizes, sampling bias, lack of control groups, reliance on self-report and qualitative rather than quantitative measurements."(4)
Sadly, detox diets and cleanses remain popular because of big-name personalities who endorse them, claiming that "detoxing" is how they keep in such great shape and stave off disease. Needless to say, that's bogus.
Such propaganda merely masks the truth. A wholesome diet and regular exercise regimen far surpass the health benefits you will ever see from a short-term juice cleanse or detox diet.
The "Master Cleanse" is a popular detox diet that entails gulping down 6 to 12 glasses of lemonade mixed with maple syrup and cayenne pepper daily for upwards of 40 days! You read that right — nearly six weeks of nothing but delicious hot-and-spicy lemonade with a sweet maple-syrup kick. Okay, you get some salty water and tea in there as well, but that's it.
This alchemical "liquid fast" is purported to provide a "total body flush"; the creator — who shall remain nameless to spare them some dignity — has even gone as far as claiming it can remedy every type of disease by bolstering your immune system. To put it mildly, that's a laughable assertion considering that this protocol is based entirely on anecdotes.
The only study on this type of juice cleanse found small changes in the inflammatory marker C-reactive protein and insulin sensitivity of menopausal women who drank lemon juice mixed with maple and palm syrups for seven days and ate no whole foods (5). These aren't profound observations given that the control group was fed a non-restrictive diet.
Of course, you're going to see some changes between a group of people eating as they please, while the other group is relegated to a very-low-calorie liquid diet. Also, note that this study was only seven days of drinking syrupy lemon juice, not 40!
Beyond that, there is a paucity of peer-reviewed evidence supporting the use of juice cleanses or detox diets to eliminate toxins or reduce body fat. But if you know how the body detoxes itself, that's not a surprise.
About all science would suggest is that an occasional water fast for a day or two can help improve cardiometabolic function (6). Still, extensive water fasts hinder kidney function, which is not conducive to toxin removal (7).
Even on a theoretical level, short-term detox diets and juice cleanses are pretty flawed concepts. Consider that heavy metals like lead and cadmium accumulate in bone and kidney tissue, respectively, where they have a half-life of many years (8).
In layman's terms: If you have an excessive concentration of lead in your body, drinking lemon juice for a week isn't going to solve that problem.
If you're wondering how to detox your body, following a juice cleanse for seven days is not the solution. Your body is continually detoxifying itself and has been since the day your mother conceived you. Detoxification is an intrinsic biological process in many species, not just humans.
The toxins and toxicants we are exposed to daily are constantly entering and being removed from the body; hence, you never notice any unusual or deleterious effects from chemicals like mercury and arsenic that creep their way into the food supply chain and public water systems.
About the only time a short-term detox is necessary is when you overdose on a drug or after acute exposure to a highly toxic xenobiotic. But even then, we're talking about a medically assisted detox, not drinking juice or smoothies for a couple of days.
If your friend overdoses on a drug or incidentally inhales a bunch of cyanide gas, would you tell them to swig down a few shots of "cleansing" fruit juice to flush their system? Hopefully not.
The prudent thing to do is rush them to a hospital (or call an ambulance) and get the appropriate medication to deactivate or counteract the offending chemical.
You can't do from a nutritional standpoint to hasten detoxifying processes beyond increasing urinary frequency and stimulating bowel movements.
Naturally, juice cleanses "work" because you drink more fluid and eat less whole food, leading to frequent urination. Many of those proprietary juice cleanse drinks also contain herbs that have natural laxative properties, so you go number two more as well. It's not that complicated. Heck, you can accomplish the same thing with a simple cup of coffee or any other caffeine-containing beverage.
The thing is, if you consume a generally wholesome diet with plenty of nutrient-dense food, a healthy liver does a pretty phenomenal job at deactivating toxins and toxicants that enter the body thanks to its vast range of enzymes. Your kidneys help filter those toxins and toxicants into the urine so they can be eliminated from the body.
If a chemical can't be filtered into the urine, it will eventually be secreted into the bile and excreted in feces. Those are your body's two major routes of detoxification: urine and feces.
Your body may also eliminate toxins and toxicants through your breath, skin, sweat, nails, and hair. However, these pathways typically contribute only a small portion to the detoxification process.
So, if your kidneys and liver aren't functioning correctly, you'll know pretty darn quick, and a 3-day juice cleanse is going to make a difference.
The harsh reality is that even if you have a toxic amount of noxious chemicals floating through your body, a short-term cleanse or detox diet isn't the remedy. Acute toxicity, such as lead poisoning, constitutes a medical emergency that requires immediate treatment. By the same token, chronic toxin exposure is rarely something you can resolve by drinking spicy lemonade for a few weeks.
The best thing you can do to continually "detox your body" is follow a proper diet with plenty of micronutrient-rich vegetables and fruits.
Remember, we have vital organs (such as the liver, kidneys, and bladder) that work around the clock to remove noxious substances and metabolic waste products. When you eat a healthy diet and hydrate adequately throughout the day, these organs will have the necessary nutrients to keep your body's innate detoxifying processes operating at full capacity.
The main message to take home is that you're better off saving your money for things that matter, like a proper diet and gym membership. There is ostensibly no scientific or clinical evidence in support of detox diets or short-term cleanses. The requisite "detox teas" and "cleanse juices" associated with these inexorable fads are so useless that it's baffling how they caught on at all.