When primary tumors liberate stray cancer cells into the circulation, for metastasis to occur such cells must first escape destruction by the immune system, and then lodge in a location where the circulation is blocked by a thrombus (fibrin clot). This was demonstrated by Dr Summer Wood of Boston in 1958 (AMA Archives of Pathology, Vol. 66, October 1958). About the same time, Dr L. Michaels of Canada reasoned that if no clots were allowed to form, then metastasis from a primary tumor could not occur, and that people with only primary cancers would in that case be in a much safer situation. This he proved to be the case. He studied the medical histories of a large number of heart and stroke patients kept on permanent anti-coagulant drug treatment to protect their blood circulation, to ascertain the incidence of cancer deaths among them, and found the incidence to be only one eighth of the expected number. The study covered the equivalent of 1569 patient/years and there was not a single case of death by cancer metastasis in the group. Thus it is easy to understand why fat is a major factor in most cancers and why herbal anti-coagulants such as garlic, aloe vera and so on assist people on high-fat diets to avoid cancer.

The major factor underlying the cancer process is improper diet. The incidence of all kinds of cancer is related more to the high intake of cooked food containing fat, protein, cholesterol, salt and preservatives than to anything else, although anything at all detrimental to the purity of the bloodstream must one way or another contribute to the problem. The deprivation of oxygen to the cells is caused not only by high blood viscosity, poor circulation and low oxygen levels, but also by the absence of the enzymes needed to process the oxygen. The respiratory enzymes may be absent because of nutrients missing from the diet*, or the respiratory enzymes may be inhibited by carcinogens in the bloodstream derived from sources such as food, smoking, alcohol, putrefaction in the colon and poisons from infected teeth.

*See "Mineral Deficiencies", Chapter 15, which outlines Dr Maynard Murray's prevention of cancer in mice.

Dr Joseph Issels of Germany, who has researched and treated cancer for fifty years, asserts that poisoning from infected teeth is one of the prime causes of cancer, and this viewpoint is supported by Dr Mulhim Hassan of Lebanon in his book Prevention and Cure of Cancer.

However, of all the many factors which in one way or another contribute to the deterioration of the milieu interieur and predispose the body to cancer, constipation appears to be by far the worst. It is important to remember that a regular daily bowel movement does not mean the absence of constipation; what counts is the time food residues take to transit the digestive tract. On the traditional Western diet of mainly cooked unsuitable food the transit time is about seventy-two hours, which means that "regular" or not, there are always stagnant putrefying residues occupying the colon producing carcinogenic substances, some of which provoke local problems and some of which perfuse back into the bloodstream. Sir William Arbuthnot Lane,* the famous British surgeon, repeatedly emphasized he had never known a single case of cancer that had not been preceded by prolonged intestinal stasis.

*Sir William Arbuthnot Lane, BART CB; Consulting Surgeon to Guys Hospital; Consulting Surgeon to The Hospital for Sick Children, London; President of The New Health Society; author of The Prevention of the Diseases Peculiar to Civilization (1929).

In his surgical practice, Sir William noted that so common were diseased colons he was forced to conclude the colon to be the seat of most chronic diseases, and for some time he specialized in the removal of diseased colons. This procedure confirmed his ideas because most of his patients' chronic disorders cleared up very quickly after losing their colons, and their overall health improved. Eventually he realized that the colon was not, itself, a troublesome organ, and became diseased only because of the kind of food people ate, and that the resulting disorders were the result of what he called 'auto-intoxication'. It was at this time in his career he became converted to the concept of natural health and thereafter concentrated his efforts on educating patients rather than cutting pieces out of them.

Professor Aviles of the Biochemistry of Cancer Department, Guadalajara, Mexico reported that out of 7715 cancer patients examined by him over a fifteen-year period, at least ninety-nine per cent had suffered from constipation and that the degree of malignancy was parallel to the degree of constipation. Doctors Dennis Burkitt and Hugh Trowell, who both spent twenty-five years working in rural Africa, agreed that in those areas where the diet of the natives consisted almost entirely of fruit and vegetables, the "transit time" of the natives was about twenty-four hours, there was no such thing as constipation and cancer was non-existent. Dr E. H. Tipper in his book The cradle of the world and cancer: a disease of civilization (1927) said:

"Cancer has been suspected of being a disease of civilization. judging from my experience in general practise in London, twenty years in West Africa, and again in rural England, I am convinced that this is true. It is due to the conventionalism and bad feeding of civilization, and is an exact index of the degree to which the alimentary tract has deviated from its natural and normal state of health. In the case of cancer, constipation and excessive meat-eating should be the two suspects, when they are present cancer is rife, where absent there is none."

However, despite the foregoing, a low-fat, low-cholesterol diet is no guarantee against cancer unless toxemia from other sources is avoided, and such toxemia is possible on a high-protein vegetarian diet containing excessive quantities of grain products and lentils. The author's observations of cancer occurring among conscientious followers of the Pritikin diet led him to suspect the heavy dependence on grain products, having previously noted the exacerbation of arthritis which accompanied excessive intake of these foods. These suspicions were confirmed by the results of the US Government's six-year Multiple Risk Factor Intervention Trial (MRFIT), evaluated in the Journal of the American Medical Association (JAMA) in Janunary 1987. The trial was conducted to evaluate the risk factors involved in coronary heart disease, in particular the relationship between blood cholesterol levels and heart attacks among the 12,000 male participants. As expected, the group with the lowest cholesterol levels (below 4.3) suffered only one quarter the death rate from heart attacks than the group with the highest cholesterol but, surprisingly, this low cholesterol group suffered just on fifty per cent more deaths from cancer than all the other groups (whose death rates from cancer were all about the same as each other), which led some doctors to believe that low cholesterol levels could actually favor the onset of cancer. But this did not make sense because all previous knowledge showed low cholesterol to be protective against cancer.

However, bearing in mind the acid-producing effects of excessive consumption of grains and other high-protein vegetables, we can explain the apparent anomaly. As Nathan Pritikin had already demonstrated before the MRFIT trial began, the only way to achieve such big reductions in blood cholesterol is to eliminate almost entirely from the diet all cholesterol-containing foods and in their place substitute cholesterol-free foods such as grain products, lentils, vegetables and fruit. This diet works wonderfully to lower cholesterol and to improve circulation, but because too little fruit is eaten and because vegetables are eaten mostly cooked and are less satisfying, and because grain products and lentils are not limited and are satisfying, it is the grain products and lentils that are consumed in excessive quantities capable of producing acid toxemia, despite the fact constipation may no longer exist. Pritikin advised the intake of copious quantities of raw salad to offset the acid formed from the grains, but it's a fact that most people just don't like eating a lot of salad and would rather stuff themselves with rice, oats or spaghetti, all of them acid forming.

The cancer process, like atherosclerosis, may take many years to develop, and the onset of the cancer growth itself usually appears in middle age or later when the vital organs have degenerated to the stage they can no longer maintain a reasonable degree of purity of the milieu interieur . In the years preceding the appearance of cancer as a growth, the tissues pass through a stage known as pre-cancer, and while the body's immune system is capable of reasonable function, any cancer cells that form, at least in the early stages, may be quickly destroyed by the immune system's white cells, providing of course that the white cells are capable of reasonable function. It should be noted that fat and cholesterol in the blood severely inhibit the white cells' activity.

Dr Max Gerson, referring to experiments with animals, said that whatever chemical assault was necessary to cause cancer in them the cancer never commenced until after the liver function became impaired, "together with pathological changes in the kidneys, spleen and lymphatic apparatus". Gerson illustrated this point with an experiment in which he completely eliminated cancer in a rat simply by interconnecting its blood circulation with that of a healthy rat whose liver was fully functional.

Primary cancer occurs mainly in tissues which in their day-to-day function have a constant wearing out and renewal of cells: tissues such as the skin, the lining of the digestive tract, the respiratory tract and the female genital canal. Apart from the fact that the cells in these tissues tend to rapidly reproduce anyway, these tissues are exposed to irritation of various kinds which promotes normal renewal growth. New growth requires temporary dedifferentiation of cells in any tissue, and if the tissue is in a pre-cancerous state any irritation or injury may be sufficient to trigger partially de-differentiated cells into becoming cancer cells. It has been postulated in the past that irritation or injury may be a cause of cancer, a postulation which of course in incorrect because irritation or injury cannot trigger cancer in healthy tissue.

Cancer is often also linked with emotional factors such as worry and grief. The two factors, physical injury and emotional stress, time and again precede the appearance of cancer, separately or together, and have often been thought to be primary causes of cancer. However, it is clear that cancer occurs only in tissue that is pre-cancerous beforehand and that irritation and emotional stress are only secondary factors, irritation by its effect on triggering cell growth, and emotional stress by its effect on depressing the cancer-fighting ability of the body's immune system. Probably in the same way emotional stress favors the onset of cancer, it has long been observed by physicians that people with melancholy personalities seem to be more prone to the disease, it being proposed there is such a thing as a "cancer personality". On the other hand, it would seem more likely that the melancholy disposition is not a cause of cancer but, like the cancer itself, just another symptom of a toxic bloodstream.

Hormone imbalance may also enter the picture; breast cancer is often associated with high levels of estrogen, the female growth hormone, and it should be noted that overproduction of estrogen is caused by high levels of fat in the diet. As Nathan Pritikin explained, it is the abnormal production of estrogen due to fat in the Western diet that accounts for the premature sexual development and bigger breasts of today's young girls.

Smoking is considered to be the primary cause of lung cancer, but research has shown that its role in producing lung cancer is mainly that of an irritant triggering new growth in tissue already pre-cancerous. Asbestos causes similar irritation. The role of smoking as a real primary cancer cause is its effect of introducing carbon monoxide into the bloodstream and reducing available oxygen to the tissues. Strong sunshine is thought to be the prime cause of skin cancer, but it is no such thing; it is an irritant which triggers new cell growth it is true, but skin cancer only eventuates in skin which is pre-cancerous, and when people adopt a low-fat, low-cholesterol diet they find the skin cancers no longer occur.

Billions and billions of dollars have been spent on desperate research to find a cure for cancer, a quest doomed to failure from the start even though doctors talk about various rates of cures obtained by surgery, radiation and chemotherapy. A person is regarded as cured of cancer if after the operation the cancer does not re-appear in five years, and all through that anxious five years or in the next maybe less anxious five years (if the patient lasts that long) nobody knows if and when the cancer will "strike" again.

Cancer can be considered "cured" only if the causes underlying it are understood and permanently removed, so that the affected tissue can become healthy again by the process of natural healing, called a spontaneous remission in medical parlance. The simple solution to the cancer problem is to stop doing the things that cause cancer. At the meeting of Nobel Laureates in Lindau, Germany on 30 June 1966, Dr Otto Warburg concluded his address as follows:

"Nobody today can say that one does not know what cancer and its prime cause be. On the contrary, there is no disease whose prime cause is better known, so that today ignorance is no excuse that one cannot do more about prevention. The prevention of cancer will come there is no doubt, for man wishes to survive. But how long prevention will be avoided depends on how long the prophets of agnosticism will succeed in inhibiting the application of scientific knowledge in the cancer field. In the meantime, millions of people must die of cancer unnecessarily."

Note: For additional hope and understanding of cancer see "Recommended Reading on Cancer" in the Appendix.