Metabolic Therapies

Health Care Professional Information

Common Name

Nutritional therapies, Gerson Regimen, Kelley therapy, Gonzalez regimen, Contreras therapy, Manner therapy

Clinical Summary

Strict dietary and detoxification regimens promoted to prevent and treat cancer and degenerative diseases, metabolic therapies are based on the theory that cancer and other diseases are caused by an accumulation of toxic substances in the body. Advocates claim that a healthy diet, detoxification practices (e.g., coffee enemas, herbal laxatives), and immune augmentation detoxify the body and allow it to heal naturally. Therapies such as the Gerson, Kelley, Contreras, Manner, and Gonzalez share this ideology but differ in modality. Diet is often based on whole foods and fresh fruits and vegetables, and is supplemented by digestive enzymes, glandular extracts, megadose vitamins, minerals, or herbal products. Agents such as hydrazine sulphate, hydrogen peroxide, or laetrile may also be administered.

Retrospective reviews of the Gerson, Kelley, and Contreras therapies show no evidence of efficacy. Recent findings from a study involving patients with inoperable pancreatic cancer showed a decrease in overall survival and poorer quality of life with proteolytic enzymes, which are often used to supplement the diet offered by metabolic therapies, compared to standard gemcitabine-based chemotherapy (1).

Although dietary remedies provide a strong sense of personal control, the strict recommendations of some metabolic therapies can cause nutritional deficiencies, while some entail potentially toxic doses of supplements or agents. Coffee enemas can cause sepsis, dangerous electrolyte deficiencies, and death.
The American Cancer Society strongly urges cancer patients not to seek treatment with metabolic therapies.

Purported Uses
  • Cancer prevention
  • Cancer treatment
  • Detoxification
Constituents

The components vary between regimen and clinic, but contain an assortment of the following:

  • Restricted “natural” diet: No processed foods
  • Detoxification: Enemas, coffee enemas, hydrogen peroxide enemas, herbal laxatives, and/or fasting
  • Nutritional supplements: High-dose vitamin C, vitamin A, B complex vitamins, magnesium, zinc, selenium, animal glandular extracts, digestive enzymes, PABA, carnitine, lecithin, inositol hexaphosphate, amino acids, and/or herbal products
  • Other agents: Laetrile, hydrazine sulfate
Mechanism of Action

Advocates of metabolic therapies claim that cancer and other diseases result from an accumulation of toxins in the body from food additives, preservatives, pesticides, and industrial pollution that disrupt the immune system and cell metabolism. The removal of these toxins through bowel purging and a healthy diet, they claim, allows the body to heal naturally. While diet may play a role in cancer prevention and some cancers are associated with environmental exposures, strict dietary restrictions, as in the Gerson regimen, cause nutritional deficiencies. Caffeine in coffee enemas is purported to cause dilation of bile ducts, bile production, glutathione S-transferase (GST) activation, and excretion of toxic breakdown products by the liver and through the colon wall. No published evidence supports these claims and no human studies examined the clinical efficacy or physiological effects of coffee enema administration. Kahweol and cafestol are constituents of green coffee that stimulate GST activation, but their activity is destroyed with roasting. Repeated administration of coffee enemas increases extravascular fluid volume and can cause serum electrolyte imbalances. Significant loss of bile salts associated with repeated long-term administration of enemas can result in malabsorption of fat, fat-soluble vitamins, and calcium.
(2) (3) (4)

Pharmacokinetics

No formal pharmacokinetic studies have been performed with metabolic diets or coffee enema administration.

Warnings

The American Cancer Society strongly urges cancer patients not to seek treatment with potentially hazardous metabolic/nutritional therapies, including the Gerson, Manner, and Contreras regimens, in Mexican border clinics.
Excessive use of coffee enemas can cause infections, dangerous electrolyte deficiencies, and death, especially when combined with fasting.
(5) (6)

Adverse Reactions

Common: Flu-like symptoms, nausea, vomiting, diarrhea, weakness, dizziness, intestinal cramping, fever, muscle aches and pains, rashes. Nutrient deficiencies (calcium, vitamins D and B12, protein), anemia, and malabsorption may result from metabolic diets (5).
Reported (Coffee enemas):

  • Electrolyte imbalance, which has resulted in serious infections (e.g., Campylobacter sepsis and amebiasis), dehydration, colitis, constipation, and death. Perforation or rupture of the colon from hard insertion devices and transfer of pathogenic microorganisms by contaminated devices are also reported (4).
  • Multiple seizures and hypokalemia leading to cardiorespiratory arrest, coma, and death were reported after excessive use of coffee enemas (1-4 per hour) for a number of days (2).
  • Death attributable to fluid and electrolyte imbalance causing pleural and pericardial effusions after use of coffee enemas, 4 per day for 8 weeks (2).
  • Serious rectal burns were reported in two patients following administration of coffee enemas. Hematochezia, rectal pain, and pain with defecation resolved after stopping the enemas (7) (8).
  • Proctocolitis has been reported in a 60-year-old woman after she self administered coffee enema for chronic constipation. Symptoms including hematochezia, tenesmus, and spastic anal pain, with low abdominal pain improved following treatment and cessation of enema (9).
  • Rectal perforation was reported in a 27-year-old woman due to benign stricture caused by rectal burns associated with hot coffee enemas (10).
Literature Summary and Critique

Retrospective analyses of the Gerson and Kelley therapies show no evidence of therapeutic efficacy. Laetrile, which the Contreras and Manner metabolic therapies employ, has been found ineffective in treating cancer.

Chabot JA, Tsai WY, Fine RL, et al. Pancreatic Proteolytic Enzyme Therapy Compared With Gemcitabine-Based Chemotherapy for the Treatment of Pancreatic Cancer. J Clin Oncol. 2010 28(12):2058-63.
Fifty-five patients with inoperable pancreatic cancer were enrolled in this controlled, observational study. Twenty-three patients chose gemcitabine-based chemotherapy, whereas 32 elected enzyme treatment that consisted of pancreatic enzymes, nutritional supplements, detoxification, and an organic diet. The two groups had no statistically significant differences in quality of life or pathology at enrollment. At one year time point, researchers observed an increase in overall survival (a 9.7 month difference in median survival) and better quality of life (P < .01) in patients who chose gemcitabine-based chemotherapy compared to those in the proteolytic enzyme group.

References
  1. Chabot JA, Tsai WY, Fine RL, et AL. Pancreatic Proteolytic Enzyme Therapy Compared With Gemcitabine-Based Chemotherapy for the Treatment of Pancreatic Cancer. J Clin Oncol. 2010;28(12):2058-63.
  2. Eisele JW, Reay DT. Deaths related to coffee enemas. JAMA 1980;244:1608-9.
  3. Josefson D. US cancer institute funds trial of complementary therapy. Western J Med 2000;173:153-4.
  4. Green S. A critique of the rationale for cancer treatment with coffee enemas and diet. JAMA 1992;268:3224-7.
  5. American Cancer Society. Questionable methods of cancer management: Questionable cancer practices in Tijuana and other Mexican border clinics. Ca: Cancer J Clin 1991;41:310-9.
  6. American Cancer Society. Questionable methods of cancer management: 'Nutritional' therapies. Ca: Cancer J Clin 1993;43:309-19.
  7. Sashiyama H, Hamahata Y, Matsuo K, et al. Rectal burn caused by hot-water coffee enema. Gastrointest Endosc. 2008 Nov;68(5):1008; discussion 1009.
  8. Jones LE, Norris WE. Rectal burn induced by hot coffee enema. Endoscopy. 2010;42 Suppl 2:E26.
  9. Keum B, Jeen YT, Park SC, et al. Proctocolitis caused by coffee enemas. Am J Gastroenterol. 2010 Jan;105(1):229-30.
  10. Kim S, Cha JM, Lee CH, Shin HP, et al. Rectal perforation due to benign stricture caused by rectal burns associated with hot coffee enemas. Endoscopy. 2012 Apr;44 Suppl 2 UCTN:E32-3.

Consumer Information

How It Works

Bottom Line: Metabolic therapies do not treat or cure cancer.

Cancer is caused by a combination of genetic and environmental factors. However, most people who promote metabolic therapies stress the environmental component, claiming that cancer is caused by an accumulation of toxins in the body from sources such as food additives, preservatives, pesticides, and industrial pollution. The removal of these toxins through bowel purging and a healthy diet, they claim, allows the body to heal naturally. Although diet may play a role in cancer prevention and it is true that some cancers are associated with environmental exposures, there are no data to show that toxins can be removed to change the course of cancer. Some aspects of metabolic diets can be harmful. For example, (1) Gerson regimen restricts diet to an unhealthy point and can cause nutritional deficiencies, (2) over-supplementation in such diets has led to toxicity and hospitalization, and (3) animal extracts were found to be contaminated.

Coffee enemas are used in several metabolic therapies. There are theories about coffee enemas aiding excretion from the liver and colon, but none of them have been proven. In addition, coffee enemas can cause electrolyte imbalances in the blood and impaired nutrient absorption.

Purported Uses
  • To detoxify the body
    No scientific evidence supports this use.
  • To prevent and treat cancer
    Most metabolic therapies have not been evaluated by clinical trials. A recent study of patients with pancreatic cancer showed a decrease in survival time and poorer quality of life in those who took proteolytic enzymes (often used to supplement diet in metabolic therapies), compared to the patients who chose standard gemcitabine-based chemotherapy.
Research Evidence

Cancer treatment
Fifty-five patients with inoperable pancreatic cancer were enrolled in a controlled, observational study. Twenty-three patients chose gemcitabine-based chemotherapy, whereas 32 elected enzyme treatment that consisted of pancreatic enzymes, nutritional supplements, detoxification, and an organic diet. The two groups had no significant differences in quality of life or pathology at enrollment. At one year time point, researchers observed an increase in overall survival and better quality of life in patients who chose gemcitabine-based chemotherapy compared to those in the proteolytic enzyme group.

Patient Warnings
  • The American Cancer Society strongly urges cancer patients not to seek treatment with potentially hazardous metabolic/nutritional therapies, including the Gerson, Manner, and Contreras regimens, in Mexican border clinics.
  • Excessive use of coffee enemas can cause infections, dangerous electrolyte imbalances, and death, especially when combined with fasting.
  • Coffee enema insertion devices should not be shared at the risk of transferring bacteria and infections.
Side Effects
  • Flu-like symptoms
  • Nausea, vomiting, diarrhea
  • Weakness, dizziness
  • Intestinal cramping
  • Fever
  • Muscle aches and pains
  • Rash
  • Nutrient deficiencies (calcium, vitamins D and B12, protein), anemia, and malabsorption
  • Coffee enemas: Electrolyte imbalance, which resulted in serious infections, dehydration, colitis, constipation, and death. Hard enema insertion devices can rupture the colon.
    Case reports:
  • Two people died from electrolyte imbalances resulting in seizures, coma, and death. One was using 1-4 coffee enemas per hour for a number of days and the other used four per day for eight weeks.
  • Serious rectal burns were reported in two patients following administration of coffee enemas. Hematochezia (passage of blood in feces), rectal pain, and pain with defecation resolved after stopping the enemas.
  • Proctocolitis (inflammation of rectum and colon) has been reported in a 60-year-old woman after she self administered coffee enema for chronic constipation. Symptoms including hematochezia (passage of blood in feces), tenesmus (a distressing but ineffectual urge to evacuate the rectum or urinary bladder), and spastic anal pain, with low abdominal pain improved following treatment and stopping the enema.
  • Rectal perforation has been reported in a 27-year-old woman following use of coffee enema. Her symptoms improved after discontinuing the enemas.
Special Point

Eating a balanced diet rich in fiber, fruits, and vegetables is known to be an important part of preventing disease, but there is no proof that diet or supplements can treat or cure cancer. Although controlling one's diet may create a greater sense of personal control, especially during cancer treatment, the extreme restrictions advocated by proponents of metabolic therapies can be harmful because they lead to severe nutritional deficiencies. In addition, cancer patients run the risk of abandoning effective conventional therapies when they choose to pursue alternative therapies.

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