Detox Diet

Autointoxication in early medical thought

The idea that waste in the intestines poisons the body is much older than the modern detox diet. A historical review by Chen and Chen states that the notion originated with physicians in ancient Egypt, who believed that a putrefactive principle associated with feces was absorbed into the circulation and produced fever and pus. The review adds that the ancient Greeks extended putrefaction to residues of food, bile, phlegm and blood within their humoral theory of disease.

In the nineteenth century, early biochemical and bacteriological studies lent some credence to the idea that bacteria acting on protein in the colon produced toxic amines. The same review names Metchnikoff among its leading proponents and describes early twentieth-century surgeons who performed colectomy for intestinal autointoxication. By the 1920s the doctrine had fallen into disrepute, because scientific advances did not support it, although the review notes that the idea persists in the public mind.

Bowel cleansing at the Battle Creek sanitarium

A McGill University Office for Science and Society article by Joe Schwarcz, dated June 2018, describes John Harvey Kellogg's Battle Creek sanitarium, where, according to the article, Kellogg believed that virtually all illnesses originated in the bowels. Patients received enemas, a yogurt treatment, and treatment in a vibratory chair intended to stimulate intestinal movement and expel toxins. The article files this approach under pseudoscience, while noting that some of Kellogg's ideas about vegetarianism have been corroborated by modern science.

Ernst's 1997 editorial in the Journal of Clinical Gastroenterology argues that colonic irrigation was revived in the late twentieth century on the same unsupported claims that had earlier been abandoned. It is a commentary rather than a trial, so it is cited here for the history of the theory and not as evidence about any present-day practice.

From historical theory to modern marketing

The sources reviewed do not trace a single origin for the modern detox diet. Klein and Kiat's 2015 critical review describes the detox industry as booming, but its abstract does not date the emergence of these diets. The British Dietetic Association calls detox diets a marketing myth rather than nutritional reality.

The historical doctrine and the modern claims are connected only loosely in the sources reviewed. Chen and Chen note the idea's persistence in public thinking, and Ernst links the later revival of colonic irrigation to the older claims. No source reviewed documents a direct line from nineteenth-century autointoxication theory to present-day juice cleanses, so this history explains the background of the claim rather than naming a documented origin.

Detoxification in medicine

In medical usage, detoxification refers to the body's own processes for breaking down and removing waste and other substances. The British Dietetic Association states that the body already detoxifies itself, and that organs including the skin, gut, liver and kidneys filter and remove waste. Its fact sheet says that no pill, drink, patch or lotion does this better.

The word has a separate clinical meaning. MedlinePlus lists detoxification and detox as alternative names for alcohol withdrawal. Its encyclopedia entry says that people with moderate-to-severe withdrawal may need treatment in a hospital or other facility, with monitoring and medicines. A clinical detoxification is therefore medical management of withdrawal, which differs from a dietary cleanse, and the two should not be read across.

Names and components of detox programs

Several names describe the practice. The NCCIH health information page uses the terms detoxes and cleanses, and describes programs that have been suggested for removing toxins from the body, losing weight or promoting health. The BDA refers to detox programmes and lists typical approaches as fasting, eating only fruit and vegetables, cutting carbohydrates and dairy, avoiding caffeine and alcohol, and using detox pills, teas or other products.

Juice-based programs are one form. The case reports describe a green smoothie cleanse and a juice diet, both built largely around juiced produce. The term toxin is seldom defined in these sources. Klein and Kiat note that the studies they reviewed measured elimination of persistent organic pollutants, a narrower outcome than the general claim. Acosta and Cash place detoxification in quotation marks when describing the body detoxification claims made for colonic cleansing.

Common features

Detox diets vary, but the sources describe a common pattern: a short period of restricted eating, often built around juices, fruit and vegetables, or water and herbal drinks, followed by a return to ordinary food. The NCCIH notes that some programs include large amounts of water and herbal tea with little or no food over several days, and that detox programs may include laxatives.

Commercial programs form a large part of the practice. Klein and Kiat describe the detox industry as booming, and the BDA lists detox pills, teas and other products among the typical approaches. The BDA also notes that detox teas act as a laxative. Colon cleansing is a separate procedure that the NCCIH mentions alongside detox programs, and the sources reviewed do not quantify how often the two are combined.

Short-term weight and fluid effects

The BDA states that rapid weight loss during fasting comes mostly from water and glycogen rather than fat, and that the weight is likely to return. The NCCIH, citing a 2017 review, says that juicing and detox diets can cause initial weight loss but tend to lead to weight gain once a person resumes a normal diet.

Huber and colleagues describe a cohort of five healthy men who followed an eight-day juice fast with very low energy intake. Triacylglycerols and insulin fell during the fast, and all measured parameters had returned to baseline one week after it ended. The abstract does not report toxin measures, so the study describes short-term metabolic change in a small group rather than any effect of detox diets on health.

Claims made for detox diets

The BDA lists the claims made for detox diets as rapid weight loss, improved digestion, better hair, nails and skin, higher energy, a boosted immune system and reduced cellulite. The NCCIH describes programs that have been suggested as ways to remove toxins, lose weight or promote health. These are claims made by programs, promoters and commentators. The sources reviewed do not establish which substances the programs remove, or that removing any substance improves health.

The BDA states that no product improves on the body's natural detoxifying process. Klein and Kiat examined the claim that detox diets enhance liver detoxification, and report that the few clinical studies of this claim used flawed methods and small samples.

Outcomes that have been measured

The outcomes measured in the studies reviewed are narrower than the claims. They include body weight and composition, insulin and inflammatory markers, lipid measures, and, in a few clinical studies, levels of persistent organic pollutants. Klein and Kiat also note that some foods, including coriander, nori and olestra, have shown detoxification properties in studies, most of which were carried out in animals.

Acosta and Cash's systematic review found that colonic cleansing has been promoted as a way to improve vitality and to minimize symptoms or prevent chronic disease, but that the data supporting body detoxification have not been studied well.

Critical reviews of detox diets

Klein and Kiat's 2015 critical review, published in the Journal of Human Nutrition and Dietetics, concludes that there is very little clinical evidence to support detox diets. It reports a handful of clinical studies showing that commercial detox diets enhance liver detoxification and eliminate persistent organic pollutants, but says these studies were hampered by flawed methodologies and small sample sizes. The authors state that, to their knowledge, no randomised controlled trials of commercial detox diets in humans had been conducted. The abstract does not state the review's search dates.

The NCCIH describes the studies of detox programs in people as few and of low quality, with design problems, few participants or no peer review. It states that there have been no studies on long-term effects, and it cites the 2015 review as finding no compelling research to support detox diets for weight management or for eliminating toxins from the body.

Systematic review of colonic cleansing

Acosta and Cash's systematic review of colonic cleansing for general health promotion concluded that there are no methodologically rigorous controlled trials supporting the practice for that purpose. It identified multiple case reports and case series describing adverse effects. The review covers colonic cleansing rather than diets, so its findings cannot be transferred to juice or food-based programs without separate evidence. Its abstract does not report search dates or the number of studies included.

Trials and cohorts

Kim and colleagues randomly assigned 84 premenopausal women with overweight to a control group without diet restriction, a pair-fed placebo diet group, or a lemon detox diet group. The intervention lasted 11 days in total, seven days of liquid diet followed by four days of transition to food. Body weight, body fat and waist-hip ratio changed more in both diet groups than in the control group, and the lemon group alone showed reduced hs-CRP. The authors attribute the body fat and insulin changes to caloric restriction.

The trial is small, short and limited to one population, and its placebo group changed in a similar way on weight and body fat. It therefore points to calorie restriction in both arms rather than a specific detox effect, and it cannot be extended to juice cleanses in general, to men, or to people with kidney or heart disease. The sources reviewed contain no randomised trial of a commercial detox diet with a toxin outcome. This reflects the limits of the sources selected, and is not the result of a systematic search for trials.

Fluid, electrolyte and nutrient effects

The NCCIH states that large amounts of water and herbal tea with no food for days could lead to dangerous electrolyte imbalances. It adds that fasting can cause headaches, fainting, weakness and dehydration, and that acute diarrhea can lead to dehydration and malabsorption.

The BDA lists dizziness among the symptoms of an extreme detox programme, alongside tiredness and poor concentration, and warns that detox teas act as laxatives. It adds that too much water can be as dangerous as too little. Neither source reports how often these effects occur, and the sources reviewed report no protein intake outcomes.

Kidney injury from high-oxalate juices

Makkapati and colleagues describe a 65-year-old woman who developed acute oxalate nephropathy after a green smoothie juice cleanse rich in oxalate. She had a remote gastric bypass and recent prolonged antibiotic therapy, and her kidney function had been normal before the cleanse. The authors state that juice cleanses increase oxalate absorption, causing hyperoxaluria and acute oxalate nephropathy in people with predisposing risk factors.

Chaudhari and colleagues describe a 68-year-old man who drank about a quart of blended vegetables a day for six months, mainly spinach, chard and beets, with an estimated oxalate intake about ten times that of a typical diet. He required hemodialysis and remained dialysis-dependent a year later. The authors judged volume depletion to probably play a major role and suggest that people prone to it may want to avoid such a diet. Neither case report gives an incidence.

Colonic cleansing and enemas

The NCCIH states that colon cleansing may have side effects, some of which can be serious. Acosta and Cash identify multiple case reports and case series describing adverse effects of colonic cleansing. Ernst describes colonic irrigation as potentially dangerous as well as useless.

Colonic cleansing is a separate procedure, and its harms cannot be transferred to diets without evidence. Acosta and Cash found the published literature on colonic cleansing to lack controlled data, so the harms they describe should be read as a separate question from dietary restriction, which the review does not address.

Suitability and care boundaries

The NCCIH says that people susceptible to kidney stone formation should limit high-oxalate foods, and that the harms of colon cleansing are more likely in people with kidney disease or heart disease. It also notes that unpasteurized juices can cause serious illness in children, older people and people with weakened immune systems.

The BDA states that cutting out food groups such as wheat and dairy is unnecessary and potentially harmful, and advises limiting fruit juice and smoothies to limit free sugar. The sources reviewed do not address eating disorders, document no liver harm, and contain no poison-center data, so these gaps remain open. Fainting, chest pain or severe weakness during a restricted diet are reasons to seek medical help promptly, and a restricted diet does not replace assessment of an existing condition.