Today in Battling Cancer we have a guest post by David Servan-Schreiber, MD, PhD,
Author of Anticancer: A New Way of Life
I am happy to forward any of your questions to him.
Genes account for at most 15% of cancers. What matters most in prevention or getting the most of treatments is not our genetic makeup but the biology we create within our body to support our natural defenses against tumor growth.
The Genetic Fallacy
Most of us live with the false belief that cancer is a genetic Russian roulette. As one in three of us will die of cancer, the odds are indeed as bad — worse actually — than those of that dreadful game. But it is NOT genetic. A large Scandinavian study of identical twins (who share exactly the same genes) found that in the majority of cases they did not share the risk for cancer. In fact, the authors concluded, in the New England Journal of Medicine, that “inherited genetic factors make a minor contribution to susceptibility to most types of [cancers]. This finding indicates that the environment has the principal role in causing common cancers.”
A New Approach to Cancer: Changing the Terrain
When it comes to treating cancer, there is no alternative to conventional treatments: surgery, chemotherapy, radiotherapy, immunotherapy or, soon, molecular genetics.
However, these treatments target the tumor much like an army wages war: focusing all of its efforts on destroying the cancerous cells. Yet, it’s as important to change the environment that supports the growth new cancer cells as it is to continue to pound them with targeted attacks.
We all need to learn to change the “terrain” — our biology — to make it as inhospitable as possible to cancer growth. As much for prevention as to increase the benefits of treatments.
The new model of cancer that has emerged from the last 10 years of research moves us away from genetics and squarely into the life-style factors that we can control.
Indeed, another New England Journal of Medicine study showed that people who were adopted at birth have the cancer risk of their adoptive parents rather than that of the parents who gave them their genes. At most, genetic factors contribute 15% to our cancer risk. What matters for 85% of cancers is what we do — or do not do enough of — with our life.
Since we all carry cancer cells in us, what determines whether we do develop cancer is to a large extent the balance between factors that promote cancer, and factors that help resist cancer.
Common promoters of cancer are:
- Cigarette smoke and more than two alcoholic beverages per day
- Refined sugar and white flour
- Omega-6 fatty acids and trans-fats (corn, soybean, sunflower and safflower oils, hydrogenated and partially hydrogenated vegetable oils)
- A variety of chemical agents present in some foods and household products (parabens, phthalates, PVCs, pesticdes and herbicides)
- Complete lack of physical activity
- Responses to stress that lead to feelings of helplessness and persistent despair rather than a sense that one can help oneself or count on the support of others
Factors that slow down the growth of cancer are:
- Several phytochemicals contained in some fruits and some vegetables, some herbs and spices.
- Omega-3 fatty acids (fatty fish, canola and flaxseed oil, flaxseeds, walnuts, some green vegetables)
- Physical activity (at least 30 minutes of walking six times a week)
- The ability to manage stress so as to avoid helplessness (emotional management through meditation or yoga or good psychotherapy) or benefiting from the support of intimate relationships, or both.
Knowing that genetics are only a minor contribution to cancer helps us realize how much is in our power to help our body be a stronger partner in nourishing life and resisting cancer.
©2008 David Servan-Schreiber, MD, PhD
David Servan-Schreiber, MD, PhD, is a clinical professor of psychiatry at the University of Pittsburgh School of Medicine and cofounder of the Center for Integrative Medicine. He lives in Pittsburgh, Pennsylvania, and Paris, France. He has been a cancer survivor for 16 years, and is the author of the International Best-Seller Anticancer: A New Way of Life, coming from Viking September 2008.