1. The dietary approach

The diet is predominantly plant-based and very high in fruits and vegetables, with approximately 13 glasses of freshly prepared juice consumed at hourly intervals. It is deliberately low in sodium and high in potassium, with foods prepared without added salt, oils and many processed foods. The slides you provided also describe potassium, Lugol’s solution, pancreatic enzymes, B vitamins and other supplements as components of the protocol.

The alkalising aspect is particularly relevant. Fruits and vegetables generally have a lower potential renal acid load (PRAL) than meat, cheese and many processed foods. Consequently, a diet dominated by plant foods can reduce dietary acid load and produce a higher urinary pH. Population research supports this relationship: greater fruit and vegetable consumption and lower meat intake are associated with more alkaline urine. 

However, it is important to distinguish urinary alkalisation from systemic alkalisation. The kidneys and lungs tightly regulate blood pH, so eating an “alkaline” diet does not simply make the blood alkaline. Changes in diet can substantially alter urine pH while having little effect on normal blood pH. 

2. Why alkalisation has been proposed in cancer

There is nevertheless an interesting biological rationale for investigating pH in cancer.

Cancer cells frequently exhibit altered metabolism, including increased glycolysis and production/export of acids. This can contribute to an acidic tumour microenvironment (TME). Experimental research suggests that tumour acidity may promote invasion, impair immune responses and contribute to resistance to some treatments. 

This creates a distinction between:

Systemic blood pH → tightly regulated

Tumour extracellular pH → can become locally acidic

Therefore, the scientifically interesting question is not simply “Can an alkaline diet make the body alkaline?”, but rather whether altering tumour acid–base physiology could influence tumour behaviour or treatment response.

There is some promising preclinical evidence that buffering tumour acidity with agents such as bicarbonate can inhibit tumour progression and potentially improve responses to treatment. However, this remains an area of investigation rather than established cancer therapy. 

3. Human evidence

There have been some small human studies investigating alkalisation alongside chemotherapy, particularly in pancreatic cancer. For example, one retrospective study used an alkaline diet together with oral sodium bicarbonate and reported longer overall survival compared with a chemotherapy-only comparison group. However, because this was not a randomised controlled trial, it cannot establish that alkalisation caused the survival difference. 

Similarly, another small study of 28 patients found that alkalisation increased urine pH and that patients achieving higher urine pH had longer survival. Again, this is hypothesis-generating rather than proof of efficacy. 

A systematic review found that, despite the biological interest in dietary acid/alkaline balance, there were no randomised clinical trials demonstrating that an alkaline diet or alkaline water treats cancer. 

4. Other components of Gerson therapy

The protocol also attempts to alter mineral and metabolic balance through:

• High potassium / low sodium intake — Gerson believed this could restore the intracellular potassium:sodium relationship.
• Fresh fruit and vegetable juices — providing substantial micronutrients and plant compounds.
• Supplements — including potassium, Lugol’s solution, vitamins and pancreatic enzymes.
• Coffee enemas — intended by Gerson to support detoxification and liver/bile function.

The proposed potassium/sodium mechanism was central to Gerson’s theory, but the NCI notes that the theories behind the detoxification and coffee-enema components have not been scientifically substantiated