WHAT CAUSES CANCER?
What causes cancer in the first place? Physicians tell me there are approximately 120 different types of cancer. Every one of them seems to begin with only one irritated cell. But the irritation must do some very specific things. Specific types of errors must be made in the genetic material called DNA, either directly or in the copying process. Suppose one mistake gets made in that part of the genetic material that contains the information that is required to make what is called a tumor supressor gene. Then the cell will not be able to repair any other part of the genetic material by itself. (The effects of a missing or defective tumor supressor gene have been recently reported on by Ramon Parsons of Columbia University.)(Parsons 1997, Science, March, 1997). Now suppose that another mistake gets made in the part of the genetic material that controls cell division so that this process goes wildly out of control.(Preston-Martin et al, 1990) What results is the beginning of cancer. What kind of cancer you get depends upon what specific kind of tissue this first "wild" cell is in.
For many years attention was focused upon the sources that irritated cells: ionizing radiation from x-rays or radioactive material, non-ionizing radiation such as ultraviolet rays, chemicals called carcinogens (e.g. toxic substances in cigarette smoke) or even certain types of viruses.
Now, of course, the medical profession is preoccupied with trying to fix the problem once it has begun, by using various procedures to kill the wildly reproducing malignant cells, or at least to stop them from reproducing. But why not focus attention on keeping cells from becoming irritated in the first place? Cancer risk is known or believed to involve genetic as well as environmental factors such as the effects of carcinogenic chemicals, radiation and perhaps certain viruses as well. But, practically speaking, unless you live in a badly polluted environment, there are only two kinds of cancer that seem to have little connection with what you eat. One is lung cancer that is induced by smoking. The other is skin cancer induced by exposing your body to direct sunlight without using some type of ultraviolet blocking lotion.