David Servan-Schreiber, MD, PhD is a clinical professor of psychiatry at the University of Pittsburgh School of Medicine and co-founder of the Center for Integrative Medicine. He lives in Pittsburgh, Pennsylvania, and Paris, France. He h...
In the last 70 years, changes in the American lifestyle have contributed to the growing cancer epidemic. Are you living a cancer-causing lifestyle? Read on to find out.
5 causes of cancer
Five major aspects of our lifestyle have changed since 1940 and contribute to the progression of cancer. These lifestyle factors include diet, exercise and environment.
1. The massive increase of sugar consumption
We went from 12 pounds of refined sugar per person per year in the 1800s to 154 pounds per person per year in 2000.
Why is this problematic? Cancer cells feed primarily on sugar. To detect where a tumor may be present in the body, we use PET scans that simply measure where radioactive sugar accumulates.
2. The changes in the way we feed animals that feed us
Animals used to feed on grass and seeds rich in omega-3 fatty acids, which slow the growth of cancer. Hence, meat, milk, cheese, butter and eggs were all rich sources of omega-3 fatty acids. Now that animals are fed in feedlots with corn and soy, omega-3s have practically disappeared from our common foods.
Eggs my grandmother used to feed me on the farm I was raised on were a genuine "health food," filled with the omega-3 DHA necessary for the growth of a child's brain. Today's supermarket eggs — unless labeled omega-3 rich — have practically no DHA and, worse, DHA has been replaced with the pro-inflammatory omega-6 arachidonic acid (AA).
What's wrong with omega-6 fat? A diet rich in omega-6 fatty acids is associated with a markedly increased risk of breast cancer. As omega-6s stimulate inflammation in the body, they are likely to feed the growth of many other types of cancer, too.
Another cancer-causing aspect of our diet is the consumption of trans-fats. Trans-fats, introduced widely in the 1960's, are now present in almost all industrial foods (pizza, cookies, French fries etc.). They are thought to increase the risk of breast cancer by a factor of 2. A Dutch government report in 2007 estimates that that the number of deaths due to trans-fats in that country exceeds the deaths due to motor vehicle accidents. Labels now carry the amount of trans fat in a product — avoid eating foods that contain this potentially cancer causing fat.
3. The introduction of chemicals in all aspects of life
DDT was invented just before WWII. Many common herbicides and pesticides mimic the effects of estrogen hormones in the body. They can stimulate the growth of an existing tumor.
In 2005, the CDC found 149 toxic chemicals in the blood and urine of Americans of all ages that were tested. In 2003 the University of Seattle tested pre-schoolers who eat conventional (non-organic) foods. The level of pesticide residue in their urine was also high. For some of them, it exceeded by a factor of 4, the limit recommended by the Environment Protection Agency (EPA). Children eating organic diets (70 percent organic or better) had practically no pesticide residue.
4. The massive reduction in our physical activity
Do you know anyone whose grandparents did not walk to school? How many children do you know today who actually walk more than 10 minutes to get to class? Something powerful has happened to our relationship with physical activity. We are the most sedentary humans that ever existed.
What can physical activity do for you? In addition to the numerous overall health benefits, physical activity can reduce the risk of a relapse from breast cancer by 50 percent in women who walk 30 minutes six times a week. Physical activity is a highly effective protector from cancer that we have eliminated from our lives.
5. The disorganization of our social support networks
We Americans now move to new homes or cities on average every five years. This means that we change neighbors, often friends, and get further and further away from our aunts and uncles, our parents and our siblings.
In times of major stress, the most effective protection from adverse psychological and physical effects on our body comes from the strength of our intimate relationships. How strong are they today when we no longer live near each other? At least 25 percent of us say that we have no one in whom we can confide.
One Australian study found that women with a major stressor in their life and no intimate support had 9.5 times more chance of developing breast cancer.
Choose to change your lifestyle and put cancer in its place
The encouraging part in this sad picture of a cancer epidemic is that each one of us can start to reverse these societal changes in our own life. We can decide to nourish our need for balance and to stimulate our health — in us and around us. We can opt for a new way of life. And, in doing so, we simultaneously help prevent cancer if we are cancer-free, and strengthen our bodies if we already have it.