Other common name(s): Gerson diet, Gerson method, Gerson treatment, Gerson program
Scientific/medical name(s): none
Gerson therapy is a form of alternative cancer treatment involving coffee enemas, supplements, juicing, and a special diet that is claimed to cleanse the body, boost the immune system, and stimulate metabolism.
Available scientific evidence does not support claims that Gerson therapy is effective in treating cancer, and the principles behind it are not widely accepted by the scientific and medical communities. It is not approved for use in the United States. Gerson therapy can be dangerous. Coffee enemas have been associated with serious infections, dehydration, constipation, colitis (inflammation of the colon), electrolyte imbalances, and even death.
How is it promoted for use?
Gerson therapy is considered a metabolic therapy (see Metabolic Therapy), and it is based on the theory that disease is caused by the body's accumulation of toxic substances. Practitioners believe that fertilizers, insecticides, herbicides, and other chemicals contaminate food by lowering its potassium content and raising its sodium content. Food processing adds more sodium, which changes the metabolism of cells in the body, eventually causing cancer.
According to practitioners of Gerson therapy, people who have cancer have too much sodium and not enough potassium in their cells. The fruit and vegetable diet that is part of Gerson therapy is used to correct this imbalance and revitalize the liver so it can rid the body of malignant cells. Coffee enemas, also part of Gerson therapy, are claimed to relieve pain and eliminate liver toxins in a process called detoxification.
The goal of metabolic therapies is to eliminate toxins from the body and enhance immune function so that the body can "fight off" cancer. Liver extract injections, pancreatic enzymes, and various supplements are said to stimulate metabolism. Proponents of metabolic therapy claim that it addresses the underlying cause of disease rather than treating the symptoms.
What does it involve?
Gerson therapy requires following a strict low-salt, low-fat, vegetarian diet and drinking juice from about twenty pounds of fresh fruits and vegetables each day. One glass of juice is consumed each hour, up to thirteen times a day. Some of the juices may be prepared ahead of time, and others must be prepared fresh each hour and drunk immediately. In addition, patients must take up to 5 coffee enemas each day, according to information on the Gerson Institute website. Various supplements, such as potassium, vitamin B12, pancreatic enzymes, thyroid hormone, and a special iodine (Lugol’s) solution, are used. All of this is intended to stimulate organ function, particularly of the liver and thyroid. Sometimes other treatments such as laetrile might also be recommended (see Laetrile).
The Gerson Institute does not own or operate any medical facilities. Instead, it refers patients to clinics it licenses. Currently the only licensed clinics are in Tijuana, Mexico and near Budapest, Hungary. Treatment for cancer is usually started at one of these inpatient clinics for a few weeks (the minimum stay at the Tijuana clinic is 2 weeks). Clinic fees can top $5,500 per week. Patients are expected to bring along a companion -- a friend, spouse, or relative -- to help with the treatment. Fees are collected up front, prior to admission. The patient continues the program at home after being discharged from the clinic.
The Gerson Institute estimates the start-up cost and the first month or so of home treatment to be over $2000 to $4,000 for equipment, supplies, supplements, organic foods, etc., depending on the type of equipment purchased. Given the frequency and involvement of the juicing, meals, enemas, etc., most people will need help with shopping and preparation. In addition, the Gerson Institute recommends buying a second refrigerator to store the produce.
Treatment may last from a few months to 10 years or more. Gerson proponents recommend that cancer patients follow the regimen for at least 2 years. People who cannot travel may opt for treatment at home without an inpatient stay.
What is the history behind it?
One of the oldest nutritional approaches to cancer treatment, the Gerson therapy was developed by Max Gerson, MD, a German doctor who immigrated to the United States in the late 1930s. He designed the dietary program to treat his own migraine headaches. He later expanded his method to treat other conditions such as arthritis, tuberculosis, and cancer. In 1945, Gerson published a preliminary report of his results in treating cancer in the Review of Gastroenterology. The National Cancer Institute and New York County Medical Society examined records of his patients and found no evidence that the method was effective against cancer.
The treatment method has evolved slightly over the years; for example, it once required drinking raw calves’ liver extract, but that was removed after the risks of raw liver were understood. An injectable liver extract was substituted.
After Max Gerson’s death in 1959, his work was carried on by his daughter, Charlotte Gerson, who established the Gerson Institute in the late 1970s. The Institute teaches others the Gerson method, and licenses clinics that closely follow their program.
What is the evidence?
There have been no well-controlled studies published in the available medical literature that show the Gerson therapy is effective in treating cancer.
In a review of the medical literature, researchers from the University of Texas MD Anderson Cancer Center identified 7 human studies of Gerson therapy that have been published or presented at medical conferences. None of them were randomized controlled studies. One study was a look-back study (retrospective review) conducted by the Gerson Research Organization in 1995. They reported that when patients with melanoma, colorectal cancer, and ovarian cancer were treated with surgery and Gerson therapy, survival rates were higher than would normally be expected, but they did not provide statistics to support the results. Other studies have been small, had inconclusive results, or have been plagued by other problems (such as a large percentage of patients not completing the study), making it impossible to draw firm conclusions about the effectiveness of treatment.
Some parts of the Gerson regimen, such as eating large amounts of fruits and vegetables and limiting fat intake, can be part of a healthy diet if not taken to extremes. Researchers are continuing to study the potential anti-cancer properties of different substances in fruits and vegetables, but their individual and collective effects are not well understood at this time. Because of this, the best evidence suggests eating a balanced diet that includes 2 and ½ cups or more a day of vegetables and fruit, choosing whole grains over processed and refined foods, and limiting red meats and animal fats as well as alcohol. Choosing foods from a variety of fruits, vegetables, and other plant sources such as nuts, seeds, whole grain cereals, and beans is likely to be healthier than consuming large amounts of one particular type of food. Based on currently available evidence, diet is likely to play a greater role in preventing cancer than in treating it.
There is very little scientific evidence to support the use of other components of the Gerson regimen, such as consuming only fresh, raw juices prepared in a certain way, eliminating salt from the diet, and “detoxifying” the liver through coffee enemas and injected liver extracts. These methods have very little scientific evidence to support their use against cancer.
Are there any possible problems or complications?
Substances used in alternative medical practices may have not been thoroughly tested to find out how they interact with medicines, foods, or dietary supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. There may also be lesser-known methods used, other than the ones discussed here, which could potentially cause harm. Because of these limitations, any information on ill effects below should be considered incomplete.
Serious illness and death have rarely occurred from some parts of the treatment, such as the coffee enemas, which remove potassium from the body and can lead to electrolyte imbalances. Continued home use of enemas may cause the colon's normal function to weaken, worsening constipation problems and colitis. Some metabolic diets used in combination with enemas cause dehydration. There is at least one report of hot enemas causing serious problems such as burns, scarring, and rectal perforation (holes).
Serious infections may result from poorly administered liver extracts. Thyroid supplements may cause severe bleeding in patients who have cancer that has spread to the liver.
The Gerson Institute Web site suggests that people with diabetes, severe kidney damage, brain metastases, recent chemotherapy, or foreign body implants (pacemakers, breast implants, etc.) should not start this method without expert consultation and supervision. Gerson therapy may be especially hazardous to women who are pregnant or breast-feeding.
Relying on this treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.
To learn more
More information from your American Cancer Society
The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).
The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management
Alternative Medicine: Expanding Medical Horizons. A Report to the National Institutes of Health on Alternative Medical Systems and Practices in the United States. Washington, DC: US Government Printing Office; 1994. NIH publication 94-066.
American Cancer Society. Questionable methods of cancer management: 'nutritional' therapies. CA Cancer J Clin. 1993;43:309-319.
Cassileth B. Gerson regimen. Oncology (Williston Park). 2010 Feb;24(2):201.
Green S. A critique of the rationale for cancer treatment with coffee enemas and diet. JAMA. 1992;268:3224-3227.
Hildenbrand G, Hildenbrand L. Defining the role of diet therapy in complementary cancer management: prevention of recurrence vs. regression of disease. Proceedings of the 1996 Alternative Therapies. Symposium: Creating Integrated Healthcare. January 18-21, 1996 San Diego, CA.
Hildenbrand GL, Hildenbrand LC, Bradford K, Cavin SW. Five-year survival rates of melanoma patients treated by diet therapy after the manner of Gerson: a retrospective review. Altern Ther Health Med. 1995;1:29-37.
Kim S, Cha JM, Lee CH, et al. Rectal perforation due to benign stricture caused by rectal burns associated with hot coffee enemas. Endoscopy. 2012 Apr;44 Suppl 2 UCTN:E32-33.
Memorial Sloan-Kettering Cancer Center. About herbs: Gerson regimen. 2011. Accessed at: http://www.mskcc.org/cancer-care/herb/gerson-regimen on August 2, 2012.
University of Texas MD Anderson Cancer Center. Gerson detailed scientific review. Accessed at http://www.mdanderson.org/education-and-research/resources-for-professionals/clinical-tools-and-resources/cimer/therapies/nutrition-and-special-diets/gerson-scientific.html on August 2, 2012. Content no longer available.
US Congress, Office of Technology Assessment. Unconventional Cancer Treatments. Washington, DC: US Government Printing Office; 1990. Publication OTA-H-405.
Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.
Last Revised: 12/11/2012