The dubious practice of detox
A growing number of infomercials, Web sites, and print articles are urging us to eliminate the systemic buildup of toxins that supposedly results from imprudent habits or exposure to hazardous substances in the environment. Such toxins, we're told, will sap our vitality and threaten our health.
This message isn't new. For thousands of years, human beings have been trying to rid their bodies of perceived toxins. Today's renewed interest in self-administered detoxification reflects concern about a variety of things, such as emerging pathogens, lead in toys, mercury in fish, etc. But do detox practices really offer benefits?
What is detox?
Before it was co-opted in the recent craze, the word "detox" referred chiefly to a medical procedure that rids the body of dangerous, often life-threatening, levels of alcohol, drugs, or poisons.
The detox programs now being promoted are largely do-it-yourself procedures aimed at eliminating alleged toxins that are held responsible for a variety of symptoms, including headache, bloating, joint pain, fatigue, and depression. Detox products are not available by prescription; they are sold in retail stores, at spas, over the Internet, and by direct mail. Here is a review of a few of the most widely promoted procedures and products.
Also known as Jala Neti or nasal lavage, this yoga-derived technique involves the use of a small pitcher (neti pot) or syringe to stream a saline solution into first one nostril, then the other. The solution passes through the nasal passage and out the other nostril or the mouth.
Purpose. Clinicians sometimes recommend nasal irrigation to rid the nose of environmental irritants, alleviate post-nasal drip, and reduce congestion from colds and allergies by flushing mucus, foreign particles, bacteria, and viruses out of the sinuses.
Evidence of effectiveness. In a handful of studies, nasal lavage has been shown to lower bacterial concentrations in nasal passages.
Risks. Fluid buildup in the sinuses.
Cost. Syringes and pitchers range from $4 to $300.
A seemingly infinite array of products and diets is available for detoxifying the entire body. One of the most popular is the Master Cleanse diet. Dieters take a quart of warm salt water in the morning; consume a 60-ounce concoction of water, lemon juice, maple syrup, and cayenne pepper throughout the day; and finish with a cup of laxative tea in the evening. Proponents of the Master Cleanse diet recommend adhering to it for at least 10 days.
Purpose. To restore energy, lose weight, and relieve symptoms of chronic conditions like arthritis and fibromyalgia.
Evidence of effectiveness. There are no data on this particular diet in the medical literature. But many studies have shown that fasts and extremely low-calorie diets invariably lower the body's basal metabolic rate as it struggles to conserve energy. Once the dieter resumes normal eating, rapid weight gain follows.
Risks. The diet is lacking in protein, fatty acids, and other essential nutrients. The daily laxative regimen can cause dehydration, deplete electrolytes, and impair normal bowel function.
Cost. The price of the book and a handful of food items.
Numerous kits are marketed for this purpose, most of which include a high-fiber supplement, a "support" supplement containing herbs or enzymes, and a laxative tea, each to be used daily. Manufacturers of the herbal detox kits recommend continuing the regimen for several weeks.
Purpose. The aim is to eradicate parasites and expel fecal matter that allegedly accumulates and adheres to the intestinal walls.
Evidence of effectiveness. Several studies suggest that milk thistle, which is often included as a supportive supplement, may improve liver function with few side effects. But there's no medical evidence for the cleansing procedure as a whole.
Risks. Like fasting, colonic cleansing carries a risk of dehydration, electrolyte imbalance, impaired bowel function, and disruption of intestinal flora.
Cost. A month's supply of the supplements and laxatives sold on most Web sites is $20 to $70. The manufacturers recommend continuing the procedure for two to three months.
The body's own detox system
We tend to forget that the body is equipped with a detoxification system of its own, which includes the following:
The skin. The main function of the body's largest organ is to provide a barrier against harmful substances, from bacteria and viruses to heavy metals and chemical toxins.
The respiratory system. Fine hairs inside the nose trap dirt and other large particles that may be inhaled. Smaller particles that make it to the lungs are expelled from the airways in mucus.
The immune system. This exquisitely orchestrated network of cells and molecules is designed to recognize foreign substances and eliminate them from the body.
The intestines. Peyer's patches — lymph nodes in the small intestine — screen out parasites and other foreign substances before nutrients are absorbed into the blood from the colon.
The liver. Acting as the body's principal filter, the liver produces a family of proteins called metallothioneins. Metallothioneins neutralize harmful metals like lead, cadmium, and mercury to prepare for their elimination from the body. Liver cells also produce groups of enzymes that regulate the metabolism of drugs and are an important part of the body's defense against harmful chemicals and other toxins.
The kidneys. The fact that urine tests are used to screen for drugs and toxins is a testament to the kidneys' remarkable efficiency in filtering out waste substances and moving them out of the body.
The bottom line
The human body can defend itself very well against most environmental insults and the effects of occasional indulgence. If you're generally healthy, concentrate on giving your body what it needs to maintain its robust self-cleaning system — a healthful diet, adequate fluid intake, regular exercise, sufficient sleep, and all recommended medical check-ups.June 2008 update