Eliminating animal protein is only one aspect of Gerson's liver therapy. Patients are also given injections composed of liver extract, administered daily for four to six months, sometimes longer. These liver injections provide vitamins, minerals, and enzymes believed to help restore the liver to its proper functioning. Intramuscular injections of liver extract are combined with vitamin B~12 injections, which Dr. Gerson held to be important for proper protein synthesis. Full restoration of the liver may take from six to eighteen months, during which time patients should have their blood monitored by a physician so that the supplements and diet can be adjusted.

Nobel Prize-winning biochemist Dr. Albert Szent-Gyorgyi believed that the liver may hold the secret of cancer prevention and cure. In 1972, he reported that extracts of mouse liver "strongly inhibited" the growth of inoculated cancer in mice. He and his associate, Dr. Laszlo Egyud, isolated from liver extract a potent anticancer substance, which they dubbed retine. This liver derivative proved so effective in the laboratory, Dr. Szent-Gyorgyi was moved to predict, "We are on the verge of finding the key to curing cancer.... Retine stops the growth of cancer cells without poisoning other cells."4

Another major feature of the Gerson therapy is restoring the balance of potassium and sodium in the body. Dr. Gerson maintained that cancer alters the body's normal sodium-to-potassium balance, already disturbed by the modern oversalted diet. Liver, brain, and muscle cells normally have much higher levels of potassium than of sodium, but in cancer patients, observed Gerson, the ratio is reversed. The Gerson therapy aims to remove as much sodium from the cancer patient's body as possible, replacing it with potassium. The diet stresses foods rich in potassium and low in sodium, with no salt added.

In addition, patients receive a potassium solution, added to juices ten times daily. Edema, or fluid retention, caused by an excess of sodium, reportedly disappears with great frequency when patients ingest high amounts of potassium in juices. Restoring potassium levels to normal in the major organs of severely ill patients can take a year or two.

Gerson's emphasis on restoring the potassium balance in cancer patients finds considerable support in modern research. Several studies outline rationales to explain Gerson's theory that elevating the potassium level while restricting sodium in the diet acts against tumor formation.5 Freeman Cope, M.D., wrote in Physiological Chemistry and Physics in 1978, "The high potassium, low sodium diet of the Gerson therapy has been observed experimentally to cure many cases of advanced cancer in man, but the reason was not clear. Recent studies from the laboratory of Ling indicate that high potassium, low sodium environments can partially return damaged cell proteins to their normal undamaged configuration. Therefore, the damage in other tissues, induced by toxins and breakdown products from the cancer, is probably partly repaired by the Gerson therapy through this mechanism."

Supplying oxygen to the cells is another central feature of the Gerson therapy. Dr. Gerson believed that cancer cells thrive by fermenting sugar in an oxygen-depleted cellular environment. This still-controversial theory, put forward by the great biochemist Otto Warburg in 1930, has some support in modern research. To enhance the patient's oxidation function, Dr. Gerson gave patients oxidizing enzymes through vegetable, fruit, and raw-calves'-liver juices. The Gerson clinic discontinued the use of raw-liverjuice in 1989, but the present diet is still a rich source of oxidation enzymes. These enzymes are also produced naturally by a healthy, restored liver. Through the Gerson treatment, "oxidation is usually more than doubled," says the patient brochure, which adds that "most 'incurable' diseases are oxygen deficiency diseases also (heart attack, strokes, cancer, etc.)."