There’s no quick fix; nurturing your health is a long-term endeavor. That doesn’t stop fad diets and the marketers promoting them from gumming up the airways with advertisements. One such diet that keeps being revived is called …
Or “detox diet”. But whichever label you prefer, you’ll be hard-pressed to associate it with a definite definition. Presumably, the goal is to cleanse the body from harmful substances, often called toxins, through a hypocaloric diet consisting of certain foods (with a possible seasoning of supplements). Some cleanses are aimed at specific organs, while others claim to purify you from head to toe.
As a rule, detox diets are very restrictive. Food is commonly limited to fruit and vegetable juices, or other approved drinks. The Master Cleanse, for example, prescribes six to twelve glasses of lemonade with maple syrup and cayenne pepper. Ingested daily as your only sustenance, this concoction supposedly removes all toxins from your body and, according to its creator, supports the elimination of every kind of disease.
While detox diets differ in their minutiae, no specific protocol is worth dissecting in detail since it will soon fall out of favor as another variant becomes the next fad.
In a nutshell, detox diets hinge on the premise that the human body accumulates toxins and metabolic waste as a result of being exposed to pesticides, pollutants, and food additives.
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.” (As we shall see, any substance can be toxic, depending on dosage.) In colloquial speech, “toxins” can also refer to toxicants, which are man-made poisons found in the environment, usually due to pollution.
In the context of detox diets, however, a “toxin” is any substance that is believed to be toxic or noxious, including heavy metals, pollutants, pesticides, preservatives, or food additives such as food coloring, high-fructose corn syrup (HFCS), and other synthetic chemicals.
However, while breathing pesticides or drinking pollutants is unambiguously harmful to your health, the same cannot be said of all non-natural food additives and modifications. Rather than falling prey to fear-mongering, let’s see what light science can shed on those gray areas of nutrition.
Toxins and toxicants cover a wide variety of substances, but non-natural substances are not automatically noxious.
Context is crucial. Natural or synthetic, any substance can be noxious, depending on many factors, such as the target species. Cocoa, for example, can be safely eaten by people, but its theobromine content makes it potentially lethal to dogs. Conjugated linoleic acid (CLA) causes fatty liver in mice, but not in humans. This is important to keep in mind because animal studies are often cited to “prove” that a substance is harmful to humans.
Dosage is another factor to consider. Even water can kill you if you drink too much over too short a period of time, since it lowers the concentration of electrolytes needed for muscles (including the heart) to function. Likewise, those same electrolytes the heart needs to keep beating aren’t always your friends. Many people know that a high sodium intake is linked to high blood pressure, but what about potassium? In the United States, the recommended daily allowance (RDA) for adults is 4.7 grams. When this much potassium is consumed through food, it is digested for hours, making it not only safe, but healthful. However, just one gram of pure potassium taken on an empty stomach, with or without water, can have adverse health effects, which is why multivitamins and sports drinks are limited to 99 milligrams (0.099 grams).
But surely some substances are always bad for you? Tobacco, for instance, or alcohol? The answer is yes. For tobacco. But alcohol isn’t an unmitigated evil. While overconsumption can lead to cirrhosis and an increased risk of cancer, small amounts may provide modest health benefits (some protection against coronary heart disease).
Then what about this modern devil, high-fructose corn syrup (HFCS)? While synthetic, this compound is close to sugar in composition and likely no worse for you. A sports drink after a workout or the occasional dessert is fine, but if you consume enough HFCS or sugars to generate a caloric surplus, you may experience health problems from the resulting weight gain.
Some substances can accumulate in body tissues, leading over time to serious health problems. This is true notably of heavy metals. Because fish can contain mercury (a heavy metal with a half-life in humans of approximately 50 days), some people have banned it from their diet, thus depriving themselves of its healthful omega-3 fatty acids. Keeping in mind that the dose makes the poison, however, you could decide instead to eat fish less frequently, vary the type of fish you eat, or focus on fish with a lower mercury content.
Pesticide residues in food are another common concern. Yet, the Pesticide Data Program (PDP) of the United States Department of Agriculture (USDA) has consistently found that the vast majority of the food on the market contained residues below the tolerable limits set by the Environmental Protection Agency (EPA). In addition, rinsing, peeling when possible, and cooking can all reduce the amount of pesticide left on your food.
Calling a compound toxic out of context is too simplistic. Other factors, most notably dosage, determine if a substance, be it synthetic or natural, is a threat to your health.
Even if a substance really is noxious, a cleanse won’t help. Acute toxicity would likely constitute a medical emergency, while chronic toxicity is best addressed by a well-fed body — not one weakened by a diet of pepper-infused lemonade. The liver, kidneys, lungs, and several other organs work around the clock to remove harmful substances and excrete the waste products of metabolism. They don’t need help from fad diets.
So, no pepper-infused lemonade. But what about commercial products? Unfortunately, a 2009 investigation found that not a single company behind 15 detox supplements could supply any form of evidence for their efficacy (or safety). Worse still, the companies couldn’t even name the toxins targeted by their products or simply agree on a definition for the word “detox”.
The fact that no company can name the toxin their product targets reveals just how little of an effect cleanses have. To scientifically determine the efficacy of a treatment, researchers must first identify the toxin, so as to accurately measure its accumulation in the body. Only then can they investigate the effects of different compounds, and should they find one that affects the toxin, explore a hypothesis regarding its mode of action.
For example, scientists researching the effects of organochlorine pesticides, which accumulate in mammals, not only know the name of the toxin they are researching, they have also determined that its accumulation can be limited by Orlistat, an anti-obesity drug. In fact, the mechanism behind this pharmaceutical’s effect is largely understood: Orlistat confines these particular pesticides to the intestines, through which they are removed as waste.
The human body does accumulate low levels of noxious elements, such as heavy metals or certain fat-soluble substances, but it has mechanisms in place to eliminate them over time. Even heavy-metal poisoning is rare, and it is then treated with chelating agents, not detox diets or products.
Studies on cleanses are scarce and, according to a recent review, not very convincing, as they suffer from “small sample sizes, sampling bias, lack of control groups, reliance on self-report and qualitative rather than quantitative measurements”. Yet, despite the lack of evidence to back their effects, detox diets and commercial cleanses remain popular, partly because many anecdotal reports seem to support their effectiveness for weight loss and overall health.
Why do fad cleanses spread through word of mouth despite the proven lack of benefits? One answer is: rapid weight loss. Which could be great … if weight loss always meant fat loss.
To store one gram of glycogen in the liver and muscles, the body uses three grams of water. Glycogen stores are easily depleted in 24–48 hours if the body isn’t getting enough carbohydrates, which results in a weight loss of several pounds. Once a regular eating schedule is resumed, however, the glycogen and water come rushing back.
Nevertheless, the temporary weight loss leads many people to attribute health benefits to the cleanse they just completed. In addition, most people eat poorly, and detox diets usually revolve around vegetables and fruits. Therefore, for most people, a detox diet means consuming fewer calories but, paradoxically, more vitamins and other valuable micronutrients. In that case, the diet is indeed beneficial, but not as much as simply eating better would be.
So, instead of doing a “spring cleanse”, focus on health habits you can sustain, such as eating nutritious food on a daily basis. Ample protein, leafy greens, and foods chock-full of vitamins are not just tastier than a cleanse, they’re also way better for you.
People eating a healthy, balanced diet comprised mainly of whole foods with minimal processing don’t need to completely avoid certain foods or restaurants. They definitely don’t need to buy into a cleanse after consuming foods that may contain unwanted additives. The evidence in support of detox diets or products just isn’t there. Until it is, you (and your wallet) are better off allowing your all-natural detoxification system to deal with the “toxins”.