Your body has a built-in detoxification system: your lungs and other organs work around the clock to remove harmful substances. Your liver, for instance, transforms noxious chemicals into benign substances that are excreted in the urine (via the kidneys) or faeces (via the gallbladder).
There are three ways a realistic detoxification program works:
1. By decreasing your exposure to known toxicants
It is wise to reduce your exposure to airborne pollutants such as smoke, smog, and chemical fumes. You don’t always get to choose where you live (e.g., rural areas tend to have less air pollution than urban areas), but you can at least reduce pollution accumulation in your home through proper air conditioning and ventilation. You can also, if you live in a smoggy area, wear a face mask — how much it’ll filter will depend on its design, including how well it fits on your face.
Pesticide residues in food are a valid concern too, though it should be noted that 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 contain either no detectable residues or residues below the tolerable limits set by the Environmental Protection Agency (EPA).
While the USDA does not currently test for residues of pesticides commonly used on organic foods, it does test for residues of pesticides not approved and some approved for limited application. Unsurprisingly, organic produce (notably fruit) less often have synthetic pesticide residue than conventional produce do. Trials in adults and children have shown that switching from conventional to organic produce can reduce biomarkers of organophosphate-class pesticides, which are used in conventional agriculture and may be harmful, in as little as a week.
When found, pesticide residues were similarly low in organic and conventional produce, but there is some evidence that even very low doses of pesticides might still elicit physiological effects. These effects, be they beneficial, neutral, or harmful, and be they from organic or conventional pesticides, are not well studied. So, what is a consumer to do? The practical solution is quite simple: rinsing, peeling when possible, and cooking can reduce the amount of pesticide left on your produce, whether this produce is organic or not.
2. By improving your liver’s ability to metabolize toxicants
Current evidence suggests that some compounds in plant foods can upregulate your liver’s detoxification process and antioxidant activity.
Of the many supplements marketed for liver health, three are supported by strong evidence from human studies: milk thistle, NAC and TUDCA.
3. By enhancing your body’s ability to excrete toxicants
Fiber, especially soluble and/or fermentable, can enhance detoxification both directly and indirectly. Directly, by binding bile and its associated toxins, thus facilitating their excretion. Indirectly, by feeding the bacteria in your digestive tract, some of which create short-chain fatty acids and other metabolites that act on the liver and kidneys to increase their ability to excrete toxicants.
Sweating may help excrete heavy metals, but sauna studies are scarce and rely mostly on subjective assessments, such as questionnaires about quality of life, rather than on objective measures of toxicant burden or excretion.
As for the notion that a juice-only cleanse can shift your guts away from digestion and toward the excretion of toxicants — it is one of those catchy ideas that lack scientific backing. If you want your organs to do their best, including to rid you of toxicants, then you should not deprive them from the nutrients they need to function. That means that, rather than the occasional cleanse, what you need is a daily diet rich in varied fruits and vegetables.