Chapter 2 – Genetics
Our genetic material determines much of what is to happen to each of us. It determines our size, general appearance, intelligence, strength, personality and, yes, our predisposition to certain diseases. Doctors often ask you if there has ever been cancer in your family. They do this to "gauge" your risk of developing the disease, especially for the kind of cancer that your family member had. This is the main reason that the general population believes that cancer risk is inherited.
The truth of the matter is that although our genetic makeup affects the risks of developing different kinds of cancer, most of the variation in cancer risk among different people and populations is due to factors that are not inherited. No more than five percent of cancers can be attributed to people's genetic material. We believe that inherited genes have been overly associated with cancer. What has been observed is that someone in a family will develop the same cancer as another family member. However, linking it strictly to the genes they have in common is not necessarily the right conclusion. We believe that cancer risk is more related to inherited behavior. Yes, behavior, which is "inherited" from one family member to another by education and imitation. Our theory is that the genetic link to cancer is more due to the fact that we eat what our parents ate and that our habits are similar to those of our parents and other relatives. So there is in fact a cancer link among relatives, but it is a behavioral link more than a genetic one.
The strongest evidence there is in support of cancer risk not being linked to people's genes comes from the study of Japanese immigrants. Cancer rates in Japan are much lower than in most other countries, especially the United States. Japanese people also develop different kinds of cancer than Americans. However, it has been demonstrated that when Japanese people move to the United States, their cancer patterns become very similar to those of Americans. The first generation to move to the US already starts to change its cancer patterns slightly. However, the next generation of Japanese-Americans (children of Japanese parents born in the US), who begin adopting American diet patterns, develop cancer profiles similar to those of Americans. The next generation, even if all the parents and grandparents are of Japanese descent, typically have American cancer rates. This clearly demonstrates that it is the environment, and in particular the diet that people follow, that determines the probability of developing cancer and the kind of cancer that one is likely to develop. If cancer was genetic, people with Japanese genes living in the US would have cancer profiles similar to Japanese people living in Japan.
This is not to say that there aren't faulty, cancer-promoting genes. Sure there are. Many have been clearly identified. But guess what … research has shown that even if you are one of the unlucky ones that inherited or developed a "bad" gene you have not necessarily been sentenced to a life with cancer. Many people that have cancer genes never develop the disease, and it's not just because of random luck. It is more than likely because they get their fair share of cancer preventers in their diet and have other cancer-preventing habits.
Sure, some people's genetic predisposition to developing cancer might be so strong that even eating all the right foods and taking all the right supplements in the proper amounts will not prevent it. However, we believe that these cases are few and far between. That is why we do not profess to have all the answers or to guarantee cancer prevention. This is one of the things the Institute, along with others, are trying to solve: how to completely eliminate the possibility of developing the disease, even if your genes say that you should get it.
Given that some people's genes have cancer written all over them, it would be great if these people knew that they have a higher probability than others of developing it. By knowing this, besides following cancer prevention strategies, people could get tests and exams on a regular basis to detect it early in case it develops. The problem is that it is very difficult to know if you have defective, high-risk genes. Tests are complicated and expensive and are not much of an option for most of us. For all you know, you have a high-risk gene, but you'll probably never know until it is too late. So the only real alternative is to defend yourself as if you had faulty genes and never have to worry about whether you do or do not.
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