Until recently lung cancer caused more deaths among men than any other form of cancer. It now ranks second to cancer of the bowel.

   Smoking not only introduces carcinogenic tars and other irritants into the lungs, but also elevates blood fats by its effect on the nervous system and simultaneously reduces oxygen available to the tissues by carbon monoxide poisoning of the red cells of the blood.

   However, not all heavy smokers get lung cancer, and at the same time there are many nonsmokers who do get lung cancer. Admittedly lung cancer is so markedly more prevalent among smokers that it is certain that smoking must be regarded as a powerful causative agent, but it could never be said that smoking was the primary cause of lung cancer.

   More directly causative of lung cancer is a high fat, high cholesterol diet. In a Chicago survey of 876 smokers, in those with cholesterol levels of 275 mg% (7.0 mm/L) the lung cancer rate was 37 per thousand.* For those with cholesterol levels of 225 mg% (5.77 m/L) the lung cancer rate was only five per thousand, but for those smokers with a cholesterol level of less than 150 mg% (3.8 mm/L) there was no cancer incidence at all.

*These figures were the number of smokers with cancer at the time of the survey. Of the 876 smokers, a far higher number will eventually get cancer.

   It is noteworthy that the Japanese, who smoke much more than the Americans, surprisingly have a much lower incidence of lung cancer, and it is further noteworthy that although over a 30 year period the percentage of American males who smoked decreased from 60% to 40%, lung cancer mortality increased three times.

   These facts do not exonerate smoking as a cause but it should be noted that the prime causative factor once again is the condition of lipotoxemia.

Cancer of the mouth, larynx and esophagus

   This kind of cancer, like all the others, stems from faulty diet and is associated with various factors which provide the necessary local irritation. Heavy drinkers are susceptible and their risk is increased twenty-fold if they smoke as well. In some countries where this form of cancer is common, the irritation is provided by heavily spiced or very hot food.

   Cancer of the esophagus is common in certain areas of Iran where the diet consists almost entirely of coarse bread. In this case the necessary condition of pre-cancer would be due not to dietary excesses, but to dietary deficiencies, there being no fruit or vegetables available.