Gerson Therapy; Its Details, Efficacy & Harms in Cancer

Gerson Protocol

This involves a very specific diet with nutritional supplements and enemas (treatment placed in the anal passage). It claims to rid the body of toxins and strengthen the body’s immune system. It was developed in the 1920’s & 30’s by a German doctor (of internal medicine) called Max Gerson. He claimed his regimen helped cure his own migraine headaches. So he went on to use it to treat other diseases such as tuberculosis and cancer. He did not have any expertise in nutritional medicine nor cancer care.

Gerson died in 1959 having had his medical license suspended a year earlier. His daughter Charlotte Gerson Straus went on to establish the Gerson Institute in 1977 which continues to promote his therapy till this day for “degenerative” diseases including cancers.

Requirements of Protocol

The Gerson protocol is based on a concept of that cancer is caused by a metabolic imbalance and returning the body back to a normal balance by removing sodium and replacing it with potassium forms the basis of his therapy. This repair is then further enhanced by “detoxifying” the body by purging using enemas while assisting the “overburdened” liver system and “deficient” pancreatic enzymes which have both become affected by presumed unknown toxins that the cancer produced. Building up the immune system with oxidants & increasing the bodies metabolic rate aided the “natural” repair process.

Each day the following is needed;

  • Drink 20 pounds (about 9 kg) of crushed fruit and vegetables – one glass of juice hourly, 13 times each day each time freshly made and consumed within 20 minutes.
  • Coffee enemas used every four hours and can be increased to every 2 hours in some cases. Alternative day castor oil orally and by enema.
  • Take supplements, including
      1. Potassium solution, Lugol’s solution (potassium iodide, iodine, water) added to the hourly juice intake
      2. Daily injectable calf or veal raw liver extract with vitamin B12 (later substituted with coenzyme Q10 and vitamin B12)
      3. Vitamins A, C, and B3 (niacin 50 mg six times daily)
      4. Flaxseed oil (also known as linseed oil)
      5. Pancreatic enzymes (pancreatin)
      6. Pepsin
      7. Thyroxine 1 grain five times daily (?dosage in a grain)

The calf raw liver practice was discontinued in the 1980s after ten patients were hospitalised with five being comatosed. It was replaced with coenzyme Q10.


It was claimed the enemas increase the flow of bile thereby cleansing the bowel and removing toxins from the body. He postulated that the caffeine stimulated the liver. He further claimed that if your body is free from toxins, it will be able to recognise and kill cancer cells.

The protocol (particularly in the first 8 weeks) excludes from the diet berries, nuts, meat, fish or dairy products, eggs, tap water, mushroom, pineapples, cucumbers, peas, lentils, seeds and oils ( except a flax to help absorb the vitamin A) and also cooking in aluminum pots and pans.

The Gerson protocol costs about $5,500 per week at the 2 institutions that offer it (in Hungary & Mexico; countries where they cant be sued for false claims). This does not include the additonal charges for friends or relatives accompanying the patient or the cost of special medication or products (such as juice presses) which the patient may need to continue the therapy at home. Although Gerson Institute brochures recommend stays of up to eight weeks with a minimum of two weeks, however most patients stay only four weeks.

Treatment can continue at home from a few months to a few years. It is important to realise that having this therapy takes a huge amount of time, energy and commitment. It can be almost a full-time job; initially 54 hours per week and reducing to 30 hours per week as a person becomes used to it.


The Evidence

Gerson described his approach in the book A Cancer Therapy: Results of 50 Cases. For treatment interventions then case studies are only useful as a preliminary stage before head to head randomised controlled trials against placebo or conventional therapy as discussed elsewhere. Despite the passing decades the Gerson Institute has been unable to produce the required standardised proof; just as we would expect from any other treatment before applying to ill people. With the large fees they are charging it would be quite easy to set up a single prospective randomised controlled trial. The Gerson Institute has produced retrospective case reviews that are highly questionable (particularly as a third of participants were not included in the statistics; intention to treat analysis) and is discussed by others. However prospective randomised controlled trials are the minimum standard which the Gerson Institute continues to fail to provide; despite the tens thousands of dollars they charge.

Even Max Gerson’s case studies had multiple problems which I will summarise here but have been discussed in detail by others (this is an essential read).

  1. Over 30 year period he had 50 claimed beneficial case studies. Where are the negative cases and how many were they. In 30 years we would expect my multitude more if the cure claimed was effective. We call this selection bias.
  2. Some of the cases did not have an established histological (biopsy) diagnosis so whether they had cancer originally is highly questionable. Some had definite benign tumours. While others had non-tumours illnesses that are also treated with radiotherapy or surgery.  This is the biggest difficulty as Gerson was not a cancer doctor he misdiagnosed many cases based upon flimsy signs such as a swollen lymph gland (which can happen with many different illnesses).
  3. Eight cases where undergoing conventional proven treatment and so whether it was his protocol or the conventional treatment that had the effect is impossible to say without head to head trials.
  4. Nearly all the cases were not followed up to ensure they remained cancer free. (This is the same for the current Gerson Institute. Three naturpaths who visited the Gerson Clinic in 1983 were able to track 18 patients over a 5-year period (or until death) through annual letters or phone calls. At the 5-year mark, only one was still alive (but not cancer-free); the rest had succumbed to their cancer.)
  5. His notes lack details that would be expected from any medical case review and this why he could not publish his findings in any medical journal as is the norm. Only one (case no. 36) of his 50 cases had sufficient information to be possibly attributed to his protocol.

However at the time period of Gerson, diagnosis was more difficult then it is today and as such Gerson can be partially excused for not bringing the required burden of proof. However this excuse is not applicable to the Gerson Institute who have both access to the means of diagnosis and the money to provide the required proof.

Several respectable medical organisations have looked into Gerson’s protocol both while he was alive and after his death.

  • The Journal of the American Medical Association, JAMA, concluded that the treatment was of no value in 1946 and again in 1949.
  • The National Cancer Institute (NCI) reviewed Gerson’s data from ten case histories in 1947 and at the full 50 case histories in 1959. NCI concluded that in most cases, basic criteria for evaluating clinical benefit were not met. NCI concluded that the data demonstrated no benefit.
  • The American Cancer Society published a statement summarizing the negative assessments of Gerson’s treatment in 1972 and again in 1991 when it discussed various “ metabolic therapies” and re-emphasised the lack of scientific evidence on the efficacy of the Gerson protocol.

Gerson protocol may be beneficial particularly psychologically and there are a few tiny indications of that with best-case series (of six participants). However it requires the development and conduct of more definite clinical randomised controlled trial as already discussed. The Gerson Institutes inability to do so or even attempt to do so is disappointing and leaves one wondering “why not try ?”.

The Gerson  Institute is non-profit organisation based in the US and does not offer treatment directly but rather licenses other centers (two so far in 45+ years; Mexico & Hungary).  Then clearly the profits of that treatment from those centers is not returning to the institute; but more than likely to individual people’s pockets.

On the current level of evidence it is not effective and promoting it above proven treatments is quackery.

Harms of Gerson Protocol

Mega-doses of juiced free fructose from fruits has been discussed elsewhere and the harm they cause on the liver leading to insulin resistance. Supplements of vitamins and antioxidants has also been discussed elsewhere and the harms they can cause. In particular, the lack of benefit on cancer, heart disease and all cause death and even increase risk of bladder cancer.

Potassium in high doses can affect the heart and lead to irregularities and heart attacks. Corporal punishment in the US with death by lethal injection includes high doses of potassium. Severe electrolyte imbalances have been reported with the Gerson protocol.

Coffee enemas are associated with severe colitis with sepsis (infection in the blood with life-threatening compromise) and also death.

Likewise if a person leaves a proven treatment for an unproven treatment their cancer will progress and possibly spread (metastasize). This makes the later return to efficacy proven conventional treatments more riskier with a more poor outcome (prognosis).

With the presence of considerable life threatening side effects then again studies are needed to determine their frequency; so that these can be weighed up against any potential benefits.


Muslim Promoters

Fortunately, the Gerson protocol, with its unproven treatment effectiveness yet very serious life-threatening side-effects (whose frequency is unknown), is not used by cancer specialists in Muslim countries. Likewise trustworthy Muslim cancer specialists, particularly those linked to public health agencies in Muslim countries, do not advocate the Gerson protocol or its like.

However despite this those with no training or skills in the fields of health, medicine or nutrition teach the Muslim masses to pursue unproven treatments like the Gerson protocol while at the same time publicly criticise public health agencies and proven treatments. The following is an example;



In response, there are good reasons why that public health agencies particularly those in Muslim countries who are a branch of the Ministries of Health and therefore attached to the government and the ruler. We have outlined some of the reasons here and more reasons can be found in the further reading section below as to why cancer specialist do not accept the Gerson protocol.

If an individual wants to the know the reasons for something which they do not understand then it is upon them to write and seek clarification from them experts within public health agencies. Criticising them publicly is blameworthy as explained by shaikh Salih al-Fawzaan who said

Complaining about governmental departments amongst the people is backbiting, corruption & way of khawaarij

انتقاد الدوائر الحكومية عند الناس مِنَ الغِيبة، وفيه إفساد، وهو شأن الخوارج – العلاّمة صالح الفوزان

So I advise everyday people to return to the specialists particularly those Muslim cancer specialist attached to the Ministry of Health in Muslim countries and be cautious of quackery. If one does not understand why the specialist in those public health agencies have taken a certain position, then write to them for clarification. Criticising them publicly is to be avoided.


The bottom line is that both Max Gerson himself and the Gerson Institute have failed to provide evidence with head to head prospective clinical randomised controlled trials to show benefit above conventional treatment or even above placebo. This is the minimal level of proof that any treatment is required to determine its efficacy and likewise to determine the risk of harm. Had the protocol worked the proof for it would be easy to provide particularly with the tens of thousands of dollars that they are charging for the initial in-patient Gerson therapy.

There are attached life-threatening harms to the Gerson protocol the extent of which is not known again due to the absence of the required trials. It is extremely time-consuming and the mega-doses of treatment is far from being “natural” as are the multiple enemas.

There are many sites on the internet advertising or promoting Gerson therapy, but they are not supported by any reputable scientific cancer organisations.

These ideas have been ported into the Muslim community by individuals that do not understand basic medical concepts of medical evidence and we have discussed them elsewhere.

A  doctor starting to use any therapy in another field does no make them an expert in that new field such as nutritional medicine or oncology. Rather one needs to return health controversies back to the experts in the field who can explain the evidences, efficacies and harms of various different treatments and put them in their appropriate contexts.

So why do people pay vasts amounts of wealth for an unproven treatment? Because many of them want to believe in some hope. Although, I too believe a 100% cures are out there for all forms of cancer waiting to be discovered, but it requires proof to establish; clutching at straws is a false ‘miracle cure’. Rejecting proven treatments that prolong life as well as quality of life years because of charlatans and quacks is deeply heart-breaking.

Further reading

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