NOTE: There is either no new research on this topic or the recent published research is weak and not appropriate for inclusion in the summary. Therefore, the information in this summary is no longer being updated and is provided for reference purposes only.

1. What is the Gerson therapy?

   The Gerson therapy has been used by some people to treat cancer and other diseases. It is based on the role of minerals, enzymes, and other dietary factors. There are 3 key parts to the therapy:

   • Diet: Organic fruits, vegetables, and whole grains to give the body plenty of vitamins, minerals, enzymes, and other nutrients. The fruits and vegetables are low in sodium (salt) and high in potassium.
   • Supplementation: The addition of certain substances to the diet to help correct cell metabolism (the chemical changes that take place in a cell to make energy and basic materials needed for the body's life processes).
   • Detoxification: Treatments, including enemas, to remove toxic (harmful) substances from the body.
2. What is the history of the discovery and use of the Gerson therapy as a complementary or alternative treatment for cancer?

   The Gerson therapy was named after Dr. Max B. Gerson (1881-1959), who first used it to treat his migraine headaches. In the 1930's, Dr. Gerson’s therapy became known to the public as a treatment for a type of tuberculosis (TB). The Gerson therapy was later used to treat other conditions, including cancer.

3. What is the theory behind the claim that the Gerson therapy is useful in treating cancer?

   The Gerson therapy is based on the idea that cancer develops when there are changes in cell metabolism because of the buildup of toxic substances in the body. Dr. Gerson said the disease process makes more toxins and the liver becomes overworked. According to Dr. Gerson, people with cancer also have too much sodium and too little potassium in the cells in their bodies, which causes tissue damage and weakened organs.

   The goal of the Gerson therapy is to restore the body to health by repairing the liver and returning the metabolism to its normal state. According to Dr. Gerson, this can be done by removing toxins from the body and building up the immune system with diet and supplements. The enemas are said to widen the bile ducts of the liver so toxins can be released. According to Dr. Gerson, the liver is further overworked as the treatment regimen breaks down cancer cells and rids the body of toxins. Pancreatic enzymes are given to decrease the demands on the weakened liver and pancreas to make enzymes for digestion. An organic diet and nutritional supplements are used to boost the immune system and support the body as the regimen cleans the body of toxins. Foods low in sodium and high in potassium are said to help correct the tissue damage caused by having too much sodium in the cells.

4. How is the Gerson therapy administered?

   The Gerson therapy requires that the many details of its treatment plan be followed exactly. Some key parts of the regimen include the following:

   • Drinking 13 glasses of juice a day. The juice must be freshly made from organic fruits and vegetables and be taken once every hour.
   • Eating vegetarian meals of organically grown fruits, vegetables, and whole grains.
   • Taking a number of supplements, including:
     • Potassium.
     • Lugol's Solution (potassium iodide, iodine, and water).
     • Coenzyme Q10 injected with vitamin B12. (The original regimen used crude liver extract instead of coenzyme Q10.)
     • Vitamins A, C, and B3 (niacin).
     • Flaxseed oil.
     • Pancreatic enzymes.
     • Pepsin (a stomach enzyme).
   • Taking coffee or chamomile enemas regularly to remove toxins from the body.
   • Preparing food without salt, spices, or oils, and without using aluminum cookware or utensils.
5. Have any preclinical (laboratory or animal) studies been conducted using the Gerson therapy?

   No results of laboratory or animal studies have been published in scientific journals.

6. Have any clinical trials (research studies with people) of the Gerson therapy been conducted?

   Most of the published information on the use of the Gerson therapy reports on retrospective studies (reviews of past cases). Dr. Gerson published case histories (detailed reports of the diagnosis, treatment, and follow-up of individual patients) of 50 of his patients. He treated several different types of cancer in his practice. The reports include Dr. Gerson's notes, with some X-rays of the patients over time. The follow-up was contact with patients by mail or phone and included anecdotal reports (incomplete descriptions of the medical and treatment histories of one or more patients).

   In 1947 and 1959, the National Cancer Institute (NCI) reviewed the cases of a total of 60 patients treated by Dr. Gerson. The NCI found that the available information did not prove the regimen had benefit.

   The following studies of the Gerson therapy were published:

   • In 1983-1984, a retrospective study of 38 patients treated with the Gerson therapy was done. Medical records were not available to the authors of the study; information came from patient interviews. These case reviews did not provide information that supports the usefulness of the Gerson therapy for treating cancer.
   • In 1990, a study of a diet regimen similar to the Gerson therapy was done in Austria. The patients received standard treatment along with the special diet. The authors of the study reported that the diet appeared to help patients live longer than usual and have fewer side effects. The authors said it needed further study.
   • In 1995, the Gerson Research Organization did a retrospective study of their melanoma patients who were treated with the Gerson therapy. The study reported that patients who had stage III or stage IV melanoma lived longer than usual for patients with these stages of melanoma. There have been no clinical trials that support the findings of this retrospective study.
   • A case review of 6 patients with metastatic cancer who used the Gerson therapy reported that the regimen helped patients in some ways, both physically and psychologically. Based on these results, the reviewers recommended that clinical trials of the Gerson therapy be conducted.
7. Have any side effects or risks been reported from use of the Gerson therapy?

   Reports of three deaths that may be related to coffee enemas have been published. Taking too many enemas of any kind can cause changes in normal blood chemistry, chemicals that occur naturally in the body and keep the muscles, heart, and other organs working properly.

8. Is the Gerson therapy approved by the U.S. Food and Drug Administration (FDA) for use as a cancer treatment in the United States?

   The Gerson therapy has not been approved by the FDA for use as a treatment for cancer or any other disease.

   For most cancer patients, nutrition guidelines include eating a well-balanced diet with plenty of fruits, vegetables, and whole-grain products. However, general guidelines such as these may have to be changed to meet the specific needs of an individual patient. Patients should talk with their health care providers about an appropriate diet to follow. Information about diet during cancer treatment is also available from the Cancer Information Service (1-800-4-CANCER) and in Nutrition During Cancer Treatment.

Complementary and alternative medicine (CAM)—also called integrative medicine—includes a broad range of healing philosophies, approaches, and therapies. A therapy is generally called complementary when it is used in addition to conventional treatments; it is often called alternative when it is used instead of conventional treatment. (Conventional treatments are those that are widely accepted and practiced by the mainstream medical community.) Depending on how they are used, some therapies can be considered either complementary or alternative. Complementary and alternative therapies are used in an effort to prevent illness, reduce stress, prevent or reduce side effects and symptoms, or control or cure disease.

Unlike conventional treatments for cancer, complementary and alternative therapies are often not covered by insurance companies. Patients should check with their insurance provider to find out about coverage for complementary and alternative therapies.

Cancer patients considering complementary and alternative therapies should discuss this decision with their doctor, nurse, or pharmacist as they would any type of treatment. Some complementary and alternative therapies may affect their standard treatment or may be harmful when used with conventional treatment.

It is important that the same scientific methods used to test conventional therapies are used to test CAM therapies. The National Cancer Institute and the National Center for Complementary and Integrative Health (NCCIH) are sponsoring a number of clinical trials (research studies) at medical centers to test CAM therapies for use in cancer.

Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Few CAM therapies have been tested using demanding scientific methods. A small number of CAM therapies that were thought to be purely alternative approaches are now being used in cancer treatment—not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health (NIH) meeting in November 1997, acupuncture has been found to help control nausea and vomiting caused by chemotherapy and pain related to surgery. However, some approaches, such as the use of laetrile, have been studied and found not to work and to possibly cause harm.

The NCI Best Case Series Program which was started in 1991, is one way CAM approaches that are being used in practice are being studied. The program is overseen by the NCI’s Office of Cancer Complementary and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients’ medical records and related materials to OCCAM. OCCAM carefully reviews these materials to see if any seem worth further research.

When considering complementary and alternative therapies, patients should ask their health care provider the following questions:

National Center for Complementary and Integrative Health (NCCIH)

The National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health (NIH) facilitates research and evaluation of complementary and alternative practices, and provides information about a variety of approaches to health professionals and the public.

CAM on PubMed

NCCIH and the NIH National Library of Medicine (NLM) jointly developed CAM on PubMed, a free and easy-to-use search tool for finding CAM-related journal citations. As a subset of the NLM's PubMed bibliographic database, CAM on PubMed features more than 230,000 references and abstracts for CAM-related articles from scientific journals. This database also provides links to the websites of over 1,800 journals, allowing users to view full-text articles. (A subscription or other fee may be required to access full-text articles.)

Office of Cancer Complementary and Alternative Medicine

The NCI Office of Cancer Complementary and Alternative Medicine (OCCAM) coordinates the activities of the NCI in the area of complementary and alternative medicine (CAM). OCCAM supports CAM cancer research and provides information about cancer-related CAM to health providers and the general public via the NCI website.

National Cancer Institute (NCI) Cancer Information Service

U.S. residents may call the Cancer Information Service (CIS), NCI's contact center, toll free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 am to 9:00 pm. A trained Cancer Information Specialist is available to answer your questions.

Food and Drug Administration

The Food and Drug Administration (FDA) regulates drugs and medical devices to ensure that they are safe and effective.

Federal Trade Commission

The Federal Trade Commission (FTC) enforces consumer protection laws. Publications available from the FTC include: