Gentle everyday detoxification: a realistic concept instead of the next cleanse
Your body is detoxifying in every second you spend reading this. So the real question is not how you switch that on, but how you can get in its way a little less.
Detoxification is not an event. It is a continuous effort of your cells that never pauses. What you can influence is not the start, but the working conditions.
It is early January. Or the Monday after a long weekend. You feel heavy, a little bloated, your head is fuzzy. And then comes the thought almost everyone has had at some point: I really should do a proper detox.
If the feeling stays, it is not a detoxification topic but a topic for medical assessment
If this feeling does not disappear after the long weekend but has been there for weeks, then it needs to be looked into first. Persistent exhaustion, water in the legs, a permanently foggy head: anaemia, a thyroid disorder, a problem with blood sugar, heart or kidneys, sleep apnoea or depression can sit behind all of these.
That belongs with your doctor first and not in a nutrition plan. With acute breathlessness, chest pain, sudden weakness or confusion, the emergency number is the right address and not an appointment. Everything else in this text assumes that this round has been done.
Shortly afterwards you are sitting in front of a website with very calming colours. Seven days. Ten days. Twenty one days. Juices, powders, herbal tea, a plan with tick boxes. At the end, a new person is supposed to be standing there.
I understand that impulse very well. It is not silly, it is human. We think in cycles of soiling and cleaning, that sits deep in us. Unfortunately, this image does not fit particularly well with what actually happens in your body.
Because your body is not waiting for January. While you read this sentence, your liver is processing medication residues, alcohol breakdown products, hormones, dyes, combustion residues from city air and dozens of substances that have no everyday name at all. It has been doing this since you were born and it does not stop.
So the interesting question sounds different. Not: How do I switch detoxification on? But: Under which conditions does this system work well, and what am I doing in everyday life that makes its work unnecessarily hard?
That is exactly what this article is about. It is the closing text of our detoxification guide, the one that puts things in order. In it, I try to separate three things cleanly: what actually happens physiologically, how much of that is covered by studies in humans, and what remains marketing.
What you can expect in this article
- What biotransformation is and why it has three stages
- Phase I, phase II and phase III explained simply
- Not only the liver: kidney, gut, skin, lungs
- Why detox cures stand on thin scientific ground
- Protein, glycine, cysteine and glutathione status
- Cruciferous vegetables and sulforaphane: the best human data
- Bitters, bile flow and what is documented about them
- Dietary fibre and the enterohepatic circulation
- Sleep as an active cleaning state of the brain
- Exercise and sweating placed in realistic context
- Alcohol and nicotine as the largest self made burden
- Letting less in: kitchen, air, cosmetics, water
- Why fasting can mobilise what has been stored
- An everyday concept you can keep up for years
What detoxification in the body really means
Let us start with the biggest misunderstanding. Almost all detox imagery works with liquid: rinsing out, washing out, flushing through. As if your body were a pipe in which sludge had settled.
That is not how it works. The technical term is biotransformation, and the word already gives everything away. The body does not simply move foreign substances along. It rebuilds them chemically.
The reason for this is banal and still the key to the whole topic. The problematic substances are almost all fat soluble. Fat soluble molecules cannot be excreted through urine, because urine is water. They would stay in the body and deposit in cell membranes and adipose tissue.
So the body has to turn a fat soluble molecule into a water soluble one. That is the actual work. And it runs in three stages.
Phase I: the docking site is attached
Enzymes of the cytochrome P450 family, predominantly in the liver, give the molecule a chemically reactive site, usually through oxidation. Figuratively speaking, a hook is screwed on to which something can later be fastened.
Phase II: the water soluble tag is coupled on
A building block that brings water solubility is hung on the hook. The most important ones are glutathione, glucuronic acid, sulfate, acetyl groups, methyl groups and the amino acid glycine. This step makes the molecule transportable.
Phase III: the pumps move it out
Active transporters such as P glycoprotein or the MRP family carry the finished conjugate out of the cell, into bile or back into the blood towards the kidney. Without this step, the product would simply stay in the cell.
Exit: bile into the gut or kidney into the urine
Larger, more fat soluble conjugates preferentially take the bile route into the gut. Smaller, well water soluble ones go through the kidney. Both routes can work to different degrees, and both can be influenced in everyday life.
These three phases are not separate departments. They are wired together, namely through nuclear receptors. Those are proteins in the cell nucleus that react to a foreign substance and then ramp up whole groups of genes.
The aryl hydrocarbon receptor responds to combustion products such as polycyclic aromatic hydrocarbons. The receptors PXR and CAR respond to a very broad spectrum of drugs and plant compounds. And Nrf2 responds to oxidative stress and to certain plant signalling substances by upregulating the phase II enzymes and protective enzymes.
A much cited review from pharmacy describes exactly this wiring. Phase I enzymes, phase II enzymes and phase III transporters are not regulated randomly but in a coordinated way, steered through AhR, PXR, CAR, PPAR, LXR, FXR and Nrf2.
What this means for you: your detoxification system is adaptable. It has a baseline output and a reserve that can be regulated upwards. It is not a rigid filter you swap out.
Xu C, Li CY, Kong AN. Induction of phase I, II and III drug metabolism/transport by xenobiotics. Arch Pharm Res. 2005Your body does not have a cleaning mode you need to start. It has a chemical factory running continuously.
A factory needs three things: raw materials, working machines and a free exit for the goods. Everything that follows in this article can be traced back to exactly these three categories. Not to the question of which powder to buy.
And now you know why the image of flushing out sits beside the physiology. It describes a transport process. At the start of the chain, however, stands a chemical rebuilding job, not a rinse.
Not only the liver: the five exits
When people think of detoxification, they think of the liver. Understandable, it is the central site of conversion. But the liver only converts. The way out is elsewhere.
Liver
This is where phase I and phase II run at their highest density. The liver decides whether a molecule is converted, stored or passed on through bile. It is a workshop, not a bin.
Kidney
It filters the blood and releases water soluble conjugates into the urine. It can only excrete what was made water soluble beforehand. Enough fluid is a basic requirement here, not a miracle cure.
Gut
What arrives through bile only leaves the body if it also leaves the gut. Otherwise it can be taken up again. That makes the gut the most underestimated part of the whole chain.
Lungs
For volatile substances, the lungs really are a direct route outwards. Part of the alcohol taken up and many solvents leave the body through exhaled air.
Skin and sweat
Emotionally the most popular route, physiologically the smallest. The data here are considerably thinner than sauna advertising suggests. I look at that in detail further down.
Adipose tissue
Not an exit but a depot. What the body cannot convert, it parks here. That is clever in the short term and, in the long term, the reason why rapid weight loss is a double edged topic.
This division explains something important. If an offer promises to clean the body, then it should be able to say through which of these routes exactly. And for which substance.
Toxicology always works through three pieces of information: which substance, which dose, which route of uptake. An offer that speaks exclusively of toxins and slag without ever naming a substance cannot answer that question. Not because it is malicious, but because it never asked the question.
As soon as someone can name a concrete substance and a concrete route, the conversation immediately becomes more honest. And usually more interesting too.
Shukri JarmoukliWhy detox cures stand on thin scientific ground
Now comes the part that is uncomfortable if you have just bought a cure. I say it anyway, because you have a right to know the state of the data.
A critical review article in the Journal of Human Nutrition and Dietetics took on exactly this question in 2015: are detox diets necessary, what do they contain, are they effective and are they dangerous?
The authors' conclusion was clear. There was very little clinical evidence supporting these diets. A handful of clinical papers had shown indications of improved detoxification performance of the liver and of excretion of persistent organic pollutants, but these studies were limited by methodological flaws and small numbers of participants. To the authors' knowledge, no randomised controlled trials existed that had tested commercial detox diets for effectiveness in humans.
For you that means: the question is not conclusively answered, but it is not answered positively either. What bothers me about it is not the product but the order. The question of effectiveness should come before the sale and not after it.
Klein AV, Kiat H. Detox diets for toxin elimination and weight management: a critical review of the evidence. J Hum Nutr Diet. 2015One distinction matters to me here, and it often gets lost. The fact that a cure has no robust evidence does not mean that people do not feel better afterwards. They often do. It is just that this is very likely due to something other than the concept.
Whoever does a week of detox usually drinks no alcohol during that week. Eats considerably more vegetables. Eats fewer ready made products. Goes to bed earlier, because no wine and no late meal get in the way in the evening. Drinks more water. Takes themselves seriously for seven days.
That is five to six real physiological changes at the same time. It would be astonishing if that did not make itself felt.
The cure gets the credit for the building blocks
The effect comes from the alcohol break, the vegetables, the sleep and the rest. It is attributed to the powder, the juice or the schedule.
And from that follows the actual damage. After the seven days the cure is over, so the five effective building blocks go as well. Instead of being kept.
That is why I consider cure thinking the central structural error in this topic. Not because the ingredients are bad, but because the time window does not fit a continuous process.
And now you know why in practice I would rather talk about twelve months than about twelve days.
Phase II needs building material, and that comes from food
Here comes the point that interests me most in this whole topic, because it is rarely told.
Phase II is an anabolic step. Something is attached. And what is attached has to be there beforehand. Glutathione, glucuronic acid, sulfate, glycine, methyl groups: these are all substances your body makes from nutrients or takes directly from food.
Glutathione is the most prominent example. It is a small protein molecule made of three amino acids: glutamate, cysteine and glycine. It is the most important endogenous antioxidant in the cell, and at the same time it is the tag for an entire branch of phase II conjugation.
So when someone says that a nutrient is important for detoxification, in this case that is not a marketing phrase. It is simply the list of materials.
A research group at Baylor College of Medicine used stable isotopes to examine glutathione synthesis in eight older and eight younger people. The older participants had markedly less glycine, less cysteine and less glutathione in their red blood cells, with a roughly halved synthesis rate.
After two weeks of supplying the two precursors cysteine and glycine, the glutathione concentration was 94.6 percent higher, the fractional synthesis rate 78.8 percent higher and the absolute synthesis rate 230.9 percent higher than before. Markers of oxidative stress fell clearly.
Important for context: the study was small, open and not controlled. The eight older participants were the ones supplemented, the eight younger ones served only as a comparison. It must therefore not be overstretched.
What this can mean for you: in this group the problem was apparently not a tired system but missing raw material. That illustrates the principle very clearly.
Sekhar RV, Patel SG, Guthikonda AP et al. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. Am J Clin Nutr. 2011Practically, that means something unspectacular: an adequate protein supply is part of the topic. Cysteine sits above all in sulfur rich protein, meaning in eggs, meat, legumes, nuts and seeds. Glycine is abundant in the connective tissue portion of meat, in bone broth, in gelatine.
Organ meats are also rich in sulfur containing protein, but here a second look is worthwhile. Liver and kidney can accumulate cadmium, and in pregnancy liver is not recommended anyway because of its high vitamin A content. As an occasional component in good quality this can make sense, as a daily portion rather not.
And exactly here many classic detox concepts have an unintended weak spot. A pure juice cure delivers fluid, potassium and secondary plant compounds. What it barely delivers is protein. So precisely the raw material from which conjugation is built.
For years we have thought of detoxification as a topic of restriction. Eat less, eat lighter, only drink.
Physiologically it is at least as much a topic of supply. A factory that is meant to produce more needs more material, not less.
What is documented here: that glutathione synthesis depends on precursors and that it increased markedly in a small study in older people when these precursors were supplied. What does not follow from that: that a particular supplement makes sense for you. That belongs in an individual assessment with history and findings, not in a blog article.
Cruciferous vegetables and sulforaphane: the best human data in the field
If you ask me which single dietary building block has the most convincing human study in this topic, then the answer is: cruciferous vegetables.
So broccoli, cauliflower, Brussels sprouts, kohlrabi, white cabbage, rocket, radishes, mustard, cress. The mechanism behind it is well described. Cruciferous vegetables contain glucosinolates, among them glucoraphanin. When they are chopped and chewed, a plant enzyme turns this into, among other things, sulforaphane.
Sulforaphane is an electrophilic compound. The cell recognises it as a mild chemical stimulus, it changes the binding between Keap1 and Nrf2 and lets Nrf2 move into the cell nucleus. There, Nrf2 switches on a whole gene group, including glutathione S transferases and further phase II enzymes.
In the rural community of He He near Qidong in the Yangtze delta, a region with considerable air pollution, 291 people were randomised for twelve weeks to receive either a broccoli sprout beverage or placebo.
What was measured was not how people felt, but something hard: the urinary excretion of the mercapturic acids of benzene, acrolein and crotonaldehyde. These are the breakdown products of these pollutants, fully conjugated with glutathione. In the sprout group, excretion of the benzene conjugates rose by 61 percent and of the acrolein conjugates by 23 percent compared with placebo. For crotonaldehyde there was no difference. The effect set in quickly and held over the full twelve weeks.
What this means for you: here it was shown in humans that an everyday food can measurably increase excretion performance for specifically named air pollutants. No more than that, but no less either. A clinical endpoint such as frequency of illness was not investigated.
Egner PA, Chen JG, Zarth AT et al. Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in China. Cancer Prev Res. 2014One detail from the same paper is interesting. Excretion of the benzene conjugate was higher in people with an intact GSTT1 gene than in people who genetically lack this enzyme, independent of group allocation. So genetics measurably plays along in this system. That explains part of why people react so differently to the same exposure.
If you take only one single thing from this article, then take this: cruciferous vegetables regularly on the plate. Not as a cure. As a normal part of your week.
In the Qidong trial, a higher excretion of conjugated air pollutants could be measured with this. Which amount makes sense for you is an individual question and not one I can answer here across the board.
Two practical notes that are not treatment instructions but kitchen knowledge. The converting enzyme myrosinase is heat sensitive. Very long boiling lowers the yield of sulforaphane. Brief steaming, sautéing or a raw portion in a salad are therefore more favourable. And mustard seeds or mustard powder, added raw, can supply part of the enzyme activity when the cabbage has been cooked more thoroughly.
Nrf2 activation has been studied very well in cell culture and animal models, while in humans it is mainly biomarkers that have been measured. In addition: Nrf2 is not a switch that should be turned up arbitrarily far. In cancer biology, permanently overactive Nrf2 signalling in tumour cells is discussed critically, because it can make those cells more resistant. Eating vegetables is something different from high dose isolated compounds. That distinction matters. And the Qidong trial worked with a standardised sprout beverage in a defined amount, not with cabbage from the plate. The transfer to a normal kitchen is plausible, but it remains a transfer.
Bitters and bile flow: old tradition, young data
Ask your grandmother what you take before a meal when food sits heavily in your stomach. The answer will be something bitter. Gentian, wormwood, dandelion, artichoke, yarrow.
This tradition is old, and physiologically it is not plucked out of thin air. Bitter receptors of the TAS2R family sit not only on the tongue. They have also been detected in the gastrointestinal tract, in the airways, in the bladder and in further locations. Their role there is being researched intensively.
The link to detoxification runs through bile. And bile is the underestimated main exit for everything that is too large and too fat soluble for the kidney.
A review in Drug Metabolism Reviews describes bile acids as signalling molecules. They activate nuclear receptors such as FXR, PXR, CAR and the vitamin D receptor.
Precisely these receptors simultaneously steer phase I oxidation, phase II conjugation and phase III transport. Bile acid metabolism and xenobiotic metabolism are therefore not two topics but one wired system.
For you that means: sluggish bile flow is not only a digestive topic. It touches the same control loop through which foreign substances are converted and transported away.
Li T, Chiang JY. Nuclear receptors in bile acid metabolism. Drug Metab Rev. 2013For the artichoke, the data are comparatively densest. A pharmacological review summarises antioxidant, choleretic, liver protective and bile flow promoting effects of artichoke leaf extract and places them in the context of its traditional use for digestive complaints. The data behind this come predominantly from preclinical work.
And now the honest limit. All of that is physiology and plant pharmacology. There are no large randomised trials showing that bitters increase the excretion of a specific environmental pollutant in humans. Anyone promising you that goes beyond the data.
For me, bitters are not a detoxification agent. They are a digestive signal.
The interesting point is a different one: bitter is a taste that has largely been bred out of many crop plants over recent decades. Lettuce, chicory, cucumber, grapefruit, much of it has become milder. We have thereby removed a sensory stimulus from everyday life without thinking much about what it used to trigger.
Practically, that does not mean buying drops, it means bringing bitter things back onto the plate. Rocket, chicory, radicchio, endive, dandelion leaves, artichoke, radishes. That is food, not a protocol.
Dietary fibre and the enterohepatic circulation
Now comes the part that almost every detox cure overlooks and that I consider one of the most important.
Imagine your liver has done everything right. Phase I, phase II, phase III. The finished conjugate goes through bile into the gut. Done, you think.
Not quite. Because in the lower small intestine sit transporters that take up bile components very efficiently and send them back to the liver. That is the enterohepatic circulation. For bile acids it makes sense, because the body does not want to build them anew all the time.
For fat soluble foreign substances, though, the same circulation means something else. They travel in a circle. The liver does the work, the gut sends them back, the liver does the work again. An exit that closes again.
A Japanese paper investigated whether rice bran fibre can increase the faecal excretion of polychlorinated biphenyls in rats, after the fibre had bound these substances in the test tube.
On a diet containing ten percent rice bran fibre, the total amount of PCB excreted in the faeces rose to 3.4 times that of the control animals. In combination with a bile acid binder it was 5.4 times. The PCB concentration in the small intestinal wall fell to 25 to 50 percent of control values.
Very important for context: this is an animal model with high fibre doses and a prescription only medication. It does not prove a comparable effect in you. But it shows very cleanly that the mechanism is plausible and that binding in the gut can be a genuine lever.
That bile acid binder was colestyramine, also spelled cholestyramine. A word on it, because the name circulates online. Colestyramine is available on prescription only in Germany and is not approved for binding environmental pollutants. Using it for that purpose would be off label, meaning outside the approved indication, with separate informed consent, a particular duty of medical justification and as a rule no reimbursement. It can impair the uptake of fat soluble vitamins and of numerous medicines and therefore requires fixed time intervals. Constipation, bloating and nausea are common. With an obstruction of the bile ducts it cannot be used. I deliberately give no dosages here, and whether something like this comes into question at all belongs in a medical conversation.
Takenaka S, Morita K, Tokiwa H, Takahashi K. Effects of rice bran fibre and cholestyramine on the faecal excretion of Kanechlor 600 (PCB) in rats. Xenobiotica. 1991In humans, comparable intervention studies with pollutant endpoints are missing. What is well studied: certain fibres can bind bile components, and insoluble fibres such as wheat bran can increase stool volume and shorten transit time. For the collective term dietary fibre this does not hold across the board, different fibres behave differently. And you do not first have to prove that chronic constipation is not the best starting position for a route of excretion.
Dietary fibre does not come from a tin. It comes from vegetables, legumes, berries, flaxseed, psyllium husks, nuts and whole grains. Variety matters more than quantity here, because different fibres have different jobs.
With the bulking fibres, meaning psyllium and flaxseed, two rules belong with them. Always with plenty of fluid, otherwise it can run exactly the other way round. And with a time interval to medicines, because they can impair their uptake. With a known narrowing in the bowel, with swallowing difficulties and when taking thyroid hormones, please clarify this medically beforehand. And increase slowly instead of going from zero to a hundred.
And now you know why a detoxification concept without a gut chapter is incomplete.
Sleep: the lever nobody can sell
There is a nice irony in this field. The probably most effective building block is the only one nobody can earn money from.
For decades it was unclear how the brain actually gets rid of its metabolic waste. It has no classic lymphatic vessels like the rest of the body. In 2013 came an answer that changed the field.
A research group in Rochester used two photon imaging in living mice to examine what changes in the brain during the transition from wakefulness to sleep.
In natural sleep and under anaesthesia, the interstitial space in the brain expanded by around 60 percent. As a result, the exchange between cerebrospinal fluid and interstitial fluid increased markedly, and the clearance rate of beta amyloid rose.
What this means for you: in this model, sleep is not a passive resting state but an active flushing state. It is, however, an animal study. Transfer to humans had not yet been shown at that point.
Xie L, Kang H, Xu Q et al. Sleep drives metabolite clearance from the adult brain. Science. 2013In 2019, a group in Boston used accelerated imaging to look at sleeping people inside a magnetic resonance scanner while EEG was recorded at the same time.
In deep sleep, a coherent pattern appeared: slow brain waves were followed by fluctuations in blood flow, and these in turn were coupled to large waves of cerebrospinal fluid. For the first time it became visible in humans that macroscopic fluid waves run through the brain during deep sleep.
For you that means: the connection between deep sleep and fluid movement in the brain is no longer a thought experiment in humans. The complete chain up to the excretion of a specific substance is not thereby proven, but the direction is clear.
Fultz NE, Bonmassar G, Setsompop K et al. Coupled electrophysiological, hemodynamic, and cerebrospinal fluid oscillations in human sleep. Science. 2019Added to that is everything else that depends on sleep and does not concern the brain. Nocturnal liver perfusion. The cortisol rhythm, which should rise in the morning and fall in the evening. Insulin sensitivity, which measurably suffers after short nights. The repair processes that mostly run at night.
You can sleep six hours and still drink a very green smoothie. Physiologically, the first decision is the considerably bigger one.
Sleep is regarded as time in which nothing happens. That is why it is the first thing to be cut when the day gets too full.
Physiologically, sleep is the shift during which the cleaning work takes place. Whoever shortens it is not shortening leisure time. They are shortening maintenance.
And now you know why in conversations about detoxification I almost always ask about sleep first and only afterwards about food.
Exercise and sweating: placed in honest context
Now it gets unpopular. I write it anyway, because otherwise you will not get a clean picture.
The idea that toxins leave the body through sweat is emotionally extremely satisfying. You see the drops. You smell them. It feels like work becoming visible.
A large review of sweat gland physiology worked through exactly this question systematically.
The conclusion: the role of sweating in the excretion of waste products and pollutants appears small compared with the routes through the kidneys and the gastrointestinal tract. Eccrine sweat glands do not adapt in order to excrete more, neither by concentrating nor through a higher sweat rate. And studies that attribute a larger role to sweat glands in excretion may, according to the author, reflect methodological artefacts rather than genuine selective transport.
For you that means: sauna and sport are good things. But not because they sweat pollutants out.
For transparency: the author works in the research department of a beverage manufacturer. That does not devalue the work, which is comprehensive and widely cited. But it belongs in the picture when you take it as the main source.
Baker LB. Physiology of sweat gland function: The roles of sweating and sweat composition in human health. Temperature. 2019There is a counter position, and I want to present it fairly. A systematic review screened 122 papers and included 24 on arsenic, cadmium, lead and mercury in sweat. In more heavily exposed people, concentrations in sweat were frequently above those in blood plasma or urine, and excretion through the skin could in individual cases reach or exceed daily excretion through urine.
The authors of this review write themselves, however, that study populations, collection methods and measured concentrations varied very widely and that adequately sized studies are lacking. It is an indication, not proof. And it explicitly concerns metals, not the large group of fat soluble organic pollutants.
The benefit is well founded, the mechanism is a different one
Exercise can speed up intestinal transit. It can improve insulin sensitivity and with it the metabolic situation in which biotransformation takes place. It can lower chronic stress and improve sleep in many people.
On perfusion of the liver and kidney the picture is more complicated than one might think. During exertion, blood is redistributed towards the musculature and splanchnic and renal perfusion fall acutely. The favourable effect on liver and kidney is more a matter of the recovery phase and of the long term metabolic situation.
These are several indirect contributions that together can be considerable. The sweat itself is not among them.
What we like about the sauna is that we see something coming out. Visibility feels like proof.
The routes that actually do the largest part of the work are invisible. They run in liver cells, in kidney tubules and at night. That is exactly why they are so hard to sell and so easy to underestimate.
Alcohol and nicotine: the largest burden is self made
An uncomfortable observation from many conversations: people invest a lot of energy in the question of which supplement supports their liver, and considerably less energy in the question of what their liver currently has to work through.
Yet the arithmetic is fairly clear. By quantity, alcohol is by far the largest foreign substance that most people supply voluntarily. Not in micrograms. In grams.
A review on alcohol and the liver describes the chain. Ethanol is broken down through alcohol dehydrogenase into acetaldehyde, with free radicals being formed that quickly bind to cellular targets, among them signalling pathways and DNA.
In addition, acetaldehyde consumes glutathione, meaning precisely that antioxidant which is at the same time needed for phase II conjugation. Chronic alcohol consumption also induces the enzyme CYP2E1, which leads to further radical formation.
For you that means: alcohol does not only occupy capacity, it consumes the same material that is needed for other tasks. That is not a moral argument, it is a biochemical one.
McKillop IH, Schrum LW. Alcohol and liver cancer. Alcohol. 2005With smoking the situation is different but similarly clear. Tobacco is a relevant source of cadmium, a heavy metal that accumulates in the renal cortex over decades and has a biological half life of many years.
In a study of 191 premenopausal women, cadmium was measured in urine and matched against smoking habits and diet.
Women with a smoking history had a geometric mean of 0.43 micrograms of cadmium per gram of creatinine, women who had never smoked 0.30. The value rose with pack years. Among the non smokers, certain foods explained part of the differences.
What this means for you: among people who smoke, smoking is probably the single most important source of cadmium. No food supplement compensates for that.
Adams SV, Newcomb PA, Shafer MM et al. Sources of cadmium exposure among healthy premenopausal women. Sci Total Environ. 2011I say this without a raised finger. For many people, alcohol has a social and emotional meaning that cannot simply be argued away. And smoking is a dependency, not a weakness of will.
What I can say, though: if someone wants to work on this topic seriously, then these are the two largest adjusting screws. Not the most exciting ones. But the largest.
Letting less in: the best documented strategy
Here comes what I find the most elegant part of the topic, and at the same time the part that practically never appears in cure concepts.
By far the largest part of detox offerings occupies itself with the output side. Getting things out, leading things out, flushing. The input side is talked about far less often. Yet the input side is exactly the area with the best human intervention studies.
Twenty people from five families who, by their own account, ate a lot from cans and packaging switched for three days to fresh foods that were not packaged in cans or plastic. Afterwards they returned to their usual diet. Urine was measured before, during and after.
The geometric mean for bisphenol A fell from 3.7 to 1.2 nanograms per millilitre, so by 66 percent. The breakdown products of the plasticiser DEHP fell by 53 to 56 percent. Among the peak values it was 76 percent for bisphenol A and 93 to 96 percent for the DEHP metabolites.
What this means for you: three days. Without a supplement, without a cure, without giving up calories. Just different packaging.
Rudel RA, Gray JM, Engel CL et al. Food packaging and bisphenol A and bis(2-ethylhexyl) phthalate exposure: findings from a dietary intervention. Environ Health Perspect. 2011In a second study, 100 adolescents used personal care products for three days that, according to their labelling, contained no phthalates, parabens, triclosan or benzophenone 3.
In urine, monoethyl phthalate fell by 27.4 percent, methylparaben by 43.9 percent, propylparaben by 45.4 percent, triclosan by 35.7 percent and benzophenone 3 by 36.0 percent. For two parabens that were detectable less often, values rose slightly and unexpectedly.
For you that means: real amounts also arrive through the skin, and there too the input side can be influenced within a few days.
Harley KG, Kogut K, Madrigal DS et al. Reducing Phthalate, Paraben, and Phenol Exposure from Personal Care Products in Adolescent Girls: Findings from the HERMOSA Intervention Study. Environ Health Perspect. 2016Then there is the living space. A quantitative meta analysis of US studies systematically evaluated house dust and found 45 chemicals that had been measured in at least three independent datasets, among them plasticisers, flame retardants, PFAS, fragrances and environmental phenols. Phthalates were present at the highest concentrations. Indoor dust is therefore a real reservoir, not a side issue.
Where the input side sits in everyday life
- Kitchen. Do not store or heat hot and fatty food in plastic. Glass, stainless steel, ceramic. Fresh rather than canned wherever possible.
- Cookware. Replace coated pans when they are scratched or flaking. Stainless steel, cast iron and enamelled cast iron are uncomplicated alternatives.
- Indoor air. Air the rooms fully several times a day, especially in well insulated flats. Let the extractor hood run after cooking.
- Dust. Wipe damp instead of stirring it up dry. Because dust is the carrier in which the substance groups mentioned accumulate.
- Cosmetics. Short ingredient lists and fewer products overall. With daily use, the skin is a relevant route of uptake.
- Drinking water. Tap water is strictly regulated in Germany. The point regulation does not cover is the plumbing in the building. With old pipes or uncertainty, a water analysis is worth more than any filter bought on suspicion.
Cure thinking asks: how do I get it out again?
The question with the better evidence base is: how much actually comes in, and how much of that is avoidable without great effort? For the short lived everyday chemicals, the answer to that is measurable and quick.
These intervention studies lowered biomarkers in urine, they did not change disease courses. That is an important difference. And they concern short lived substances that the body processes within hours to days. For long lived legacy loads in adipose tissue, the same does not apply in the same way.
The uncomfortable part: fasting and weight loss mobilise what is stored
You will find this section in hardly any detox text, and I consider it one of the most important.
Persistent organic pollutants such as PCBs, certain organochlorine pesticides and dioxins are fat soluble and hard to break down. The body therefore stores them in adipose tissue. As long as the fat stays, they stay there relatively quietly.
When fat is broken down, they go along into the blood.
Thirty nine people with obesity were fed a calorie reduced diet for 15 weeks. Blood and subcutaneous adipose tissue were examined before and afterwards for 26 organochlorine compounds.
Organochlorine pollutants were found in every single participant. After a mean weight loss of 9.5 kilograms, all 19 detected compounds had risen in blood, and for 15 of them statistically significantly. The rise correlated with the extent of weight loss and persisted even after an 18 week follow up.
What this means for you: losing weight makes sense for health and this finding does not change that. It does change something about the question of the pace at which, and under which accompanying conditions, it should take place.
Chevrier J, Dewailly E, Ayotte P et al. Body weight loss increases plasma and adipose tissue concentrations of potentially toxic pollutants in obese individuals. Int J Obes Relat Metab Disord. 2000The finding has been described several times. A paper from the same research direction showed that these increases were linked to changes in fasting insulin in men, but not in women. A cross sectional investigation in postmenopausal women found higher organochlorine concentrations in women who had larger weight losses behind them.
A review in Diabetes and Metabolism brought the thought together and discusses whether released pollutants could explain part of those unexpected unfavourable effects observed in some weight loss studies, up to a possible involvement in the weight regain afterwards. That is explicitly a hypothesis, not a proven causal relationship.
Radical cures are, of all things, the worse idea here
A very strict juice cure is exactly the combination you would least wish for in this context: strong calorie restriction and therefore high fat mobilisation, plus little protein for conjugation and often little fibre for binding in the gut.
So more release alongside a narrower processing and excretion side. That is no reason to panic. But it is a very good reason to take pace and support seriously.
If you have a known exposure, are planning a pregnancy, are breastfeeding or have a liver disease, this consideration belongs in a medical conversation and not in a self experiment.
And now you know why in this topic I so often talk about speed and so rarely about intensity.
What is documented and what is not
I find it important to put this side by side cleanly in one place. Not so that you do less, but so that you know how confident you may be about which point.
An everyday concept you can keep up for years
When I pull all of this together, no plan with day numbers emerges. What emerges is an attitude with three questions you can ask yourself at any time.
The three questions
- Is something coming in that would not have to come in? Alcohol, smoke, hot food in plastic, unaired rooms, ten cosmetic products where three would do. This is the side with the best evidence base.
- Does my system have material and time? Enough protein, plenty of vegetables with a cruciferous share, real nights. A factory without raw material and without a maintenance window works less well, no matter how well it is built.
- Is the exit open? Dietary fibre, fluid, exercise, regular bowel movements. The most unspectacular part and the one where something most often gets stuck.
If you want to change something tomorrow and cannot do everything at once, then I would start in this order.
Three levers for the next four weeks
- Sleep gets an appointment. A fixed bedtime that you keep even when the evening is still pleasant. The adjusting screw is not the alarm clock, it is the start.
- Cruciferous vegetables in almost every meal. Rocket on the plate, broccoli in the pan, cabbage in the salad, radishes as a snack. Cook briefly instead of boiling long. Two restrictions belong with this, and they matter more than they sound. If you take an anticoagulant of the warfarin or phenprocoumon type, meaning a vitamin K antagonist, please do not change your cabbage intake on your own but discuss it with your practice beforehand. Cruciferous vegetables are rich in vitamin K, and a sudden change can shift your INR. And if a thyroid disorder or an iodine deficiency is known, the amount belongs in a medical conversation as well, because glucosinolates in large amounts can act in a goitrogenic way.
- One packaging rule. Warm and fatty food no longer touches plastic. That is one single habit, and in studies it changed something measurably within three days.
These are deliberately not dosages and not protocols. What makes sense in practice depends on your history, your findings, your medication and your life situation. That is exactly why this part belongs in a conversation and not in a text written for everyone at the same time.
The real gain is not a cleaner body after ten days. It is a system that works under better conditions over years. That is unspectacular and that is exactly the point.
And right at the end there is something for me that goes beyond laboratory values. This topic is not really about toxins. It is about the question of how much consideration you give in everyday life to a body that works for you without interruption and never asks for anything. Whoever asks that question seriously once usually changes more afterwards than any cure could bring about.
And now you know why I consider detoxification a lifestyle topic and not a product.
Frequently asked questions
What does detoxification in the body actually mean?
The technical term is biotransformation. The body does not simply wash substances out, it rebuilds them chemically until they are water soluble enough to leave the body through bile or urine.
In phase I, molecules are given a docking site through enzymes of the cytochrome P450 family, often through oxidation. In phase II, a water soluble building block is attached to that site, for example glutathione, glucuronic acid, sulfate, glycine or a methyl group. In phase III, active pumps transport the finished conjugate out of the cell.
These three stages are wired together through nuclear receptors such as AhR, PXR, CAR and Nrf2. Detoxification is therefore not a cleaning process, it is a chemical factory with a need for raw materials.
Do detox cures achieve anything scientifically?
Commercial detox cures lack a foundation. A critical review article in the Journal of Human Nutrition and Dietetics concluded in 2015 that, to the knowledge of the authors, no randomised controlled trials existed that had tested the effectiveness of commercial detox diets in humans.
The few available clinical papers were limited by methodological flaws and small numbers of participants, and part of the evidence came from animal experiments.
That does not mean nothing happens. Anyone who drinks no alcohol for a week, eats more vegetables and goes to bed earlier does change something real. It is just that this comes from those building blocks, not from the cure as a concept. And exactly those building blocks could be kept.
Is sweating an important route of detoxification?
For the vast majority of substances, no. A comprehensive review of sweat gland physiology concludes that the role of sweating in the excretion of waste products and pollutants appears small compared with the kidneys and the gastrointestinal tract. The glands cannot deliberately raise their excretion rate, neither by concentrating nor by producing more sweat.
A systematic review on arsenic, cadmium, lead and mercury in sweat did find higher concentrations in sweat than in blood or urine in some more heavily exposed people. The 24 included papers were, however, very heterogeneous in methodology and collection technique, and the authors themselves call for adequately sized studies.
Sauna and exercise have their value, among other things through perfusion, intestinal transit, metabolic situation and sleep. As a route of excretion for pollutants, however, they are not the main channel.
Why do cruciferous vegetables come up so often in this topic?
Because one of the few robust human trials sits here. In a randomised trial in the Chinese province of Jiangsu, 291 people from a region with heavy air pollution received a broccoli sprout beverage or placebo for twelve weeks.
What was measured was the urinary excretion of the mercapturic acids of benzene and acrolein, meaning the fully conjugated breakdown products. Benzene conjugates rose by 61 percent and acrolein conjugates by 23 percent compared with placebo. For crotonaldehyde there was no effect.
The mechanism behind this is well described: sulforaphane changes the binding between Keap1 and Nrf2, whereupon Nrf2 upregulates whole gene groups of phase II enzymes. Important for context: what was measured was better conversion and better excretion, not a clinical endpoint.
What do bitter substances have to do with detoxification?
The connection runs through bile. Everything the liver has coupled to glutathione or glucuronic acid in phase II is released to a considerable extent into the gut through bile.
Bile acids are not only emulsifiers, they are signalling molecules themselves that intervene in the regulation of phase I, phase II and phase III through nuclear receptors such as FXR, PXR and CAR. Bitter receptors of the TAS2R family also sit not only on the tongue but in the gastrointestinal tract as well. For artichoke leaf extract, choleretic effects have been described.
What remains honest: this is well documented physiology and plant pharmacology, but not large randomised evidence for the endpoint of pollutant excretion in humans. That is why I treat bitters as a digestive topic, not as a detoxification agent.
Why is dietary fibre important for detoxification?
Because of the enterohepatic circulation. What arrives in the gut through bile can be taken up again in the lower small intestine and travels back to the liver. For fat soluble substances that means a holding pattern instead of an exit.
Certain fibres can bind bile components and shorten transit time. In rat experiments with polychlorinated biphenyls, faecal excretion rose to 3.4 times that of control animals on a diet containing ten percent rice bran fibre, and to 5.4 times in combination with a bile acid binder.
That is an animal model with high fibre doses and a prescription only medication, not a human trial. The mechanism, meaning binding in the gut and faster transit, is in principle the same process in humans. Whether it applies in a comparable order of magnitude in humans is not shown by this. And that chronic constipation is physiologically the opposite of a good excretory situation holds independently of that.
What role does protein play in detoxification?
An underestimated one. Phase II consumes building material, and a large part of that is amino acids. Glutathione itself consists of glutamate, cysteine and glycine. Glycine is additionally used directly for conjugations.
In a study at Baylor College of Medicine, older people had only about half as much glutathione in their red blood cells as younger comparison participants, with a clearly reduced rate of new synthesis. After two weeks with the precursors cysteine and glycine, the glutathione concentration was 94.6 percent higher and the absolute synthesis rate 230.9 percent higher than before.
The study was small, with eight older and eight younger participants. But it illustrates very clearly: no raw materials, no conversion. And exactly here pure juice cures have a weak spot, because they barely deliver protein.
How are sleep and detoxification connected?
Above all in the brain. In a mouse model, a paper in Science showed that the interstitial space in the brain expands by around 60 percent during sleep and that the exchange between cerebrospinal fluid and interstitial fluid increases markedly as a result.
In humans, accelerated imaging showed in 2019 that slow brain waves, fluctuations in blood flow and waves of cerebrospinal fluid occur in a temporally coupled way during deep sleep. Taken together, both findings make it plausible that sleep is an active cleaning state for the brain.
For the rest of the body it also holds that liver perfusion, insulin sensitivity and the cortisol rhythm depend on sleep. It is therefore the one lever nobody can sell and no supplement can replace.
Can a fasting cure release stored pollutants?
Yes, and this is the most uncomfortable point in this field. Fat soluble environmental pollutants accumulate in adipose tissue. When fat is broken down, they enter the blood.
In a study of 39 people with obesity, all 19 detected organochlorine compounds in blood rose after 15 weeks of calorie reduced eating and a mean weight loss of 9.5 kilograms, and for 15 of them the increase was statistically significant. The effect correlated with the extent of weight loss.
A review article in Diabetes and Metabolism discusses this mechanism as a possible explanation for unexpected unfavourable effects after intensive weight loss programmes. That is not an argument against losing weight. It is an argument for a moderate pace, for enough protein and fibre, and for not regarding radical cures as harmless.
What is the point of reducing exposure from outside?
Of all the approaches, this is the best documented one. In an intervention study with 20 people from five families, mean urinary bisphenol A values fell by 66 percent and DEHP breakdown products by 53 to 56 percent after only three days of fresh food that was not packaged in cans or plastic.
In a second study with 100 adolescents, three days with cosmetics declared to be lower in these substances lowered, among others, monoethyl phthalate by 27.4 percent, methylparaben by 43.9 percent, triclosan by 35.7 percent and benzophenone 3 by 36.0 percent.
These effects are fast, measurable and available without any cure. They do, however, concern short lived substances, not the long lived legacy load in adipose tissue. And what was measured were biomarkers, not disease courses.
How do I recognise whether a detox offer can deliver on its own promises?
This is not a judgement about individual providers, most of whom I do not know at all. These are the three questions I ask myself before I take a concept seriously.
First: there is talk of toxins or slag without any concrete substance ever being named. Toxicology always works with substance, dose and route of uptake.
Second: a time window is being sold, usually seven, ten or twenty one days, followed by a relapse into the old everyday routine. Biotransformation runs around the clock, and a sprint does not fit a continuous process.
Third: there is no measurement taken before and afterwards, but there is a very clear promise. Conversely, I find it convincing when someone states which substance is meant to leave by which route, what is documented about that and what is not.
What would be three levers I can start with right away?
First, treat sleep as an appointment and not as leftover time, because this is where the best combination of depth of effect and zero cost lies. A fixed bedtime is the actual adjusting screw, not the alarm clock.
Second, keep the excretory side open, meaning fibre from vegetables, legumes and flaxseed, enough fluid and regular bowel movements as a simple everyday criterion.
Third, reduce the input side, concretely less alcohol, no smoking, no heating or storing of warm food in plastic, regular airing and damp dusting. That sounds unspectacular. And that is exactly the point: you can do these things for years, and biotransformation is a permanent topic, not a project.
Where this topic connects
Detoxification never stands alone. It touches liver, gut, hormonal axes, sleep and nutrient supply at the same time.
Guide Detoxification
All articles on biotransformation, environmental exposure, liver, gut and the limits of the detox market.
Current sectionHormonal disruption and the environment
Why plasticisers, phenols and other environmental factors can reach into hormonal axes.
HormonesGut, digestion and excretion
Why the gut is the most underestimated part of the entire chain of excretion.
GutSleep, stress and exhaustion
Why sleep is physiologically not a break but the shift during which maintenance takes place.
GuideSources
All studies were cross checked via PubMed and are linked with a DOI. On the question of whether a particular nutritional or lifestyle concept lowers pollutant exposure in humans over the long term, there are so far no large, long term and methodologically unassailable studies. The connections presented here rest on physiology, on mechanistic work from cell culture and animal models, on individual randomised and controlled intervention studies with biomarker endpoints, and on observational data. That is biologically plausible and in parts well measured, but not documented with the same certainty as through large randomised trials with clinical endpoints.
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This text does not replace medical advice or individual diagnostics. It deliberately contains no dosages and no treatment protocols. If you take medication, have a liver or kidney disease, are pregnant, are breastfeeding, want to have a known pollutant exposure investigated or are planning a substantial weight loss, every decision involved belongs in medical hands. This applies in particular with vitamin K antagonists, with thyroid disorders, with gallstones and with known narrowings in the bowel. The considerations described here are not intended for children and adolescents.