An essential detoxification process takes place in the liver.  This is a two-phase process involving a series of enzymes.

Peter Bennett, N.D., and Stephen Barrie, N.D., describe it in their book 7-Day Detox Miracle: Restore Your Mind and Body's Natural Vitality with This Safe and Effective Life-Enhancing Program.  "Think of this detoxification process as a two-phase wash cycle.  Enzymes are like the soap that liberates grease into little droplets, removing impurities that the water can't remove on its own.  In the first part of the wash cycle, enzymes break toxins down into intermediate forms...Some toxins are ready for elimination at this stage, but others require a second wash cycle.  In Phase Two, these intermediate compounds are routed along one of six chemically driven detoxification pathways, where they are further broken down, and then bound to specific types of protein molecules which act as 'escorts' to guide them out of the body, allowing them to exit through the kidneys (in the form of urine) or the bile (in the form of feces).  This process is called conjugation."  (Pg. 97-98.)

Many toxins are fat-soluable.  The liver's job is to transform them into water-soluable substances so they can be excreted via the colon or the kidneys.  (The bowel and the kidneys cannot process them out until they're water-soluable.)  When hormones, drugs, chemicals or other toxins enter the liver in the blood, the first group of enzymes, the Phase One detoxification system, go to work to transform them. When the Phase One enzymes have "biotransformed" the toxins into intermediate forms, Phase Two enzymes combine with the "biotransformed intermediates" to create nontoxic water-soluable compounds that can then be excreted.  If there aren't enough nutrients to generate these Phase Two enzymes, a dangerous bottle-neck in the detoxification process is created. The necessary enzymes are derived from various vitamins and minerals,  plus amino acids (glycine, glutamine, taurine, methionine, cysteine and glutathione) found in high quality proteins.

These biotransformed intermediates have another name we're now more familiar with, oxygen free radicals, and if they can't be immediately processed out due to lack of nutrients, they begin to cause oxidative stress within the liver and to other tissues where they're carried in the bloodstream. The free radicals, can be MORE DANGEROUS than they were in their original form as toxins entering the liver.

Dr. Bland reports "These intermediary materials have adverse effects upon the hormone-secreting endocrine system (the thyroid, adrenal and pancreatic glands), the immune system, which provides the body's defenses, and the nervous system. These three organ systems seem to be most sensitive to endo- and exotoxicity [that is, toxins of internal and external origin], and the symptoms patients experience are often related to thyroid difficulties, adrenal stress problems, immune hypersensitivity or immune suppression problems associated with increased inflammation or "catching every bug that comes along," and chronic nervous system problems that may, in some individuals, progress to become such serious disorders as Parkinson's or Alzheimer's disease." (The 20-Day Rejuvenation Diet Program, Pg. 116)

The enzyme system in the liver is very delicate. Like the antioxidant system, it depends on having the right combination of an assortment of nutrients that is almost impossible to get without nutritional supplementation, even from a very healthy diet. The enzyme system is also subject to great genetic variation. Dr. Bland reports that when all the health-conscious members of his staff had their liver detoxification processes tested, they found a 10-fold difference in Phase One detoxification ability among these "normal" individuals. "In fact," he writes, "individuals among the staff who had the slowest cytochrome P450 [i.e. the liver's enzyme system] detoxification activity were the most sensitive, with histories of allergy, asthma and environmental sensitivity. On the other end of the continuum, those who had very active cytochrome P450 and liver detoxification systems appeared to be the staff members who never got sick when they traveled internationally, experienced no allergies to foods or other substances and had no eczema or asthma." (Pg. 114)

Another complicating factor can be that a person may naturally have one phase that works better than the other. Fortunately, there is now simple, noninvasive testing that tests a person's Phase One and Phase Two detoxification processes, allowing the individual to make dietary and nutritional adjustments to account for their individual differences.