Thursday, June 16, 2016

Detox diets for toxin elimination and weight management: a critical review of the evidence

Introduction
- Detoxification or ‘detox’ diets are short-term interventions designed to eliminate toxins from the body, promote health and assist with weight loss.
- Detox diets range from total starvation fasts to juice fasts to food modification approaches and often involve the use of laxatives, diuretics, vitamins, minerals and/or ‘cleansing foods’
- The most common reasons cited by naturopathic doctors for prescribing detox therapy are environmental exposure to toxins, general cleansing/preventative medicine, gastrointestinal disorders, autoimmune disease, inflammation, fibromyalgia, chronic fatigue syndrome and weight loss
- A selection of popular commercial detox diets is shown in Table 1.

What is the definition of ‘toxin’?
- Despite the widespread popularity of detox diet the term ‘toxin’ remains ill-defined.
- Approaches to detoxification generally exploit pathways that promote the excretion of chemicals and their metabolites in urine and faeces or extrarenal excretion in sweat or sebum
- In the context of commercial detox diets, the term ‘toxin’ has adopted a much hazier meaning; encompassing pollutants, synthetic chemicals, heavy metals, processed food and other potentially harmful products of modern life
- Commercial detox diets rarely identify the specific toxins they aim to remove or the mechanisms by which they eliminate them, making it difficult to investigate their claims.
- The detox industry founds itself on the notion that chemicals can be neatly divided into ‘good’ and ‘bad’ categories; in reality, for the vast majority of chemicals, it is the ‘dose that makes the poison’.

What are the evidences of detox diets?
- No rigorous clinical investigations of detox diets have been conducted. The handful of studies that have been published suffer from significant methodological limitations including small sample sizes, sampling bias, lack of control groups, reliance on self-report and qualitative rather than quantitative measurements.

Exposure to chemicals: should we be concerned?
- In both the European Union (EU) and the USA, approximately 80 000 chemicals are currently in use
- It is well-established that some synthetic chemicals accumulate in the human body and that high doses can be toxic  
- The detox industry operates on the principle that any level of a foreign chemical in the body should be a cause for concern, although this notion is unsubstantiated.
- A panel of experts from the United Nations Environment Programme and the World Health Organisation (WHO) concluded in 2012 that, ‘although it is clear that certain environmental chemicals can interfere with normal hormonal processes, there is weak evidence that human health has been adversely affected by exposure to endocrine-active chemicals’.
- Our body is consistently exposed to many ‘toxic’ substances, such as: Persistent organic pollutants (POPs), Phthalates, Biphenol A (BPA), metals (Hg, Pb, Cd, Ar, Al) and even moulds. Their source ranging from food that we eat, cosmetics products, household products, food packaging, and even the capsule coatings of nutritional supplements! They are virtually everywhere! (ZYL)
- The human body has evolved highly sophisticated mechanisms for eliminating toxins. The liver, kidneys, gastrointestinal system, skin and lungs all play a role in the excretion of unwanted substances.
  
Is there a role for nutrition in detoxification?
There are some preliminary studies suggesting that certain nutritional components possess detoxification properties. As shown in Table 2 (note that mostly are animal studies and the humans studies are of low quality).

 Are detox diets effective for weight management?
- Currently, no scientific studies have investigated the effectiveness of commercial detox diets for losing weight.
- Because one of the principal claims of the detox industry is that these diets are useful for shedding weight, this is an area that requires attention.

Possible health risk of detox diets
- The main health risks of detox diets relate to severe energy restriction and nutritional inadequacy. Extreme fasting can lead to protein and vitamin deficiencies, electrolyte imbalance, lactic acidosis and even death
- Detox dieters are also at risk of overdosing on supplements, laxatives, diuretics or even water
- The lack of regulation in the detox diet industry is a major concern. (There are reports that companies are replacing the words ‘detox’ and ‘cleansing’ with alternatives such as ‘reinvention’ and ‘revamp’, making it increasingly difficult to regulate the detox industry)
- In some cases, the components of detox products may not match their labels
  
Conclusion
- At present, there is no compelling evidence to support the use of detox diets for weight management or toxin elimination.
- Considering the financial costs to consumers, unsubstantiated claims and potential health risks of detox products, they should be discouraged by health professionals and subject to independent regulatory review and monitoring.

- There is no doubt that sustained healthy habits are of greater long-term value than the quick fixes offered by commercial detox diets.


(This is an open access article. Click here!)

1 comment: