US epidemiologist: ‘Genes give us the gun, environment pulls the trigger’ in cancer

US epidemiologist: ‘Genes give us the gun, environment pulls the trigger’ in cancer

“Genes give us the gun, while the environment pulls the trigger,” the prominent US epidemiologist Devra Davis told Kathimerini in an exclusive interview ahead of her speech at a conference titled “Dramatic Changes on the Planet and the Greek Roots of Ecological Ethics,” which took place at the University of Patra in southwestern Greece between June 17- 20.

Davis emphasizes that awareness and prevention regrading unhealthy factors in our environment, including information on the use of cell phones, is a fundamental human right. Davis is president of the Environmental Health Trust and visiting professor at the Hebrew University Hadassah Medical School in Jerusalem and Ondokuz Mayis Medical School in Samsun, Turkey.

You underline that the war on cancer since the 1970s has focused on the wrong enemies with the wrong weapons. What do you mean by that?

The search for a cure for cancer has driven the effort against the disease for more than a century. The war focused on treating cancer, not on preventing it. The enemy was seen as the disease, but not the things that caused it. And the weapons became a series of drugs, some of which could cure the cancer but also killed the patient.

Thus when reports first surfaced that workers were experiencing higher rates of cancer from asbestos, benzidine and vinyl chloride, companies secretly funded experimental research aimed at exonerating their products. When that failed, they went on to suppress information about the dangers to workers. This information about the documented dangers of these products was only discovered after lawyers pursued lawsuits on behalf of sick or dead workers and their families.

For cancer and any chronic disease, there are three types of prevention. Primary prevention means keeping cancer from developing in the first place by identifying its causes and reducing and controlling them. Secondary prevention involves screening programs for cancer that detect early disease. Tertiary prevention involves managing and controlling disease. Devising poison drugs to fight back the illness produced a few dramatic successes – chiefly for childhood leukemia. But the basic treatment for some of the most common and aggressive cancers like those of the lung has changed very little over the years.

What lessons have been learned in the treatment of chronic diseases in recent times?

You can pay now or you can pay a lot more later. If you think of the example of HIV-AIDS, the greatest success has come from preventing the disease by frank education, much more so than from treatment. While treatment is obviously important, the best way to reduce the burden is to identify the causes and reduce or eliminate them.

Do you believe cancer is related to environmental exposure? And if so, what does this mean in terms of therapy?

Cancer has long latencies and multiple causes. Inherited genetics play a very small role for most cancers, explaining less than 10 percent of breast and colon cancer according to the National Cancer Institute.
Studies of identical twins that I will refer to in my talk indicate that they are born with very similar chromosomes – not surprisingly since they come from the same egg. The astonishing thing is that by age 50 the same chromosomes from the same twins seem to have no relationship to one another.

We know that farmers develop certain cancers more than others even though they don’t smoke and lead a relatively healthy life. My colleagues and I have written a series of papers in which we find non-Hodgkin’s lymphoma, prostate cancer, melanoma and breast cancer associated with farming. We believe that pesticides, engine exhaust, and other factors play an important role in producing higher rates of some cancers for people who work on farms.

From studies of migrants, we also learned that people tend to acquire the risk of cancer of the country that they move to, indicating again the importance of the environment.
Basically we can say that genes give us the gun, while the environment pulls the trigger.

Recent work on epigenetics confirms that there are ongoing interactions between the environment and our bodies throughout our lives. For cancer patients it is very important that they try to eat a healthy diet, maintain a balanced life, and avoid exposure to agents that could be tumor-promoting, such as mobile phone radiation, pesticides, alcohol or other toxic materials.

Are people informed about the consequences and impact of wireless devices on public health and the environment? What about mobile phones?

There is an appalling lack of information about avoidable causes of cancer, which is why we created the Environmental Health Trust. We are working to educate and motivate people about widespread health risks. When it comes to mobile phones and other wireless devices, evidence is growing in animals and humans showing that regular exposure over a lifetime increases the risk of many types of disease, including highly malignant and aggressive brain cancer.

I am more concerned about the short term for our children because a growing array of effects on the developing brain and behavior have been demonstrated in experimental studies. A study from Korea showed that the children with the highest lead levels also had the greatest amount of attention problems if they also used cell phones. This is indicating an interaction between lead and mobile phone radiation, which could be explained by the fact that this radiation weakens membranes, allowing any toxic material in the blood to get more deeply into any cells, including those of the brain.

The Cleveland Clinic website advises men who wish to become fathers to get their phones out of their pockets. This is because extensive research has shown that phone radiation damages the capacity of sperm to swim, reduces sperm count, impairs sperm quantity and quality. Our website ( has extensive information on this and other issues.

Is scientific research and development of environmental issues reliable, or do you think it has been influenced by industry bias?

Industry has cut back it’s own research in this field dramatically. The Chinese have a proverb: A way of looking is a way of not looking – or if you don’t want to know, don’t ask.
Government funding for research and training and monitoring is also very, very limited, especially in the United States right now where there are many uncertainties and unpredictabilities regarding support for science among other things. There is no routine monitoring for adverse affects of mobile phone radiation despite the fact that all devices come with information inside their operating systems warning to keep them between 15 millimeters and 2.5 centimeters away from the body.

My colleagues and I believe that people have a fundamental human right to know this information and should not have to find it buried in the operating system. In fact it is an underestimate of what is needed. People need to know that a cell phone is a two-way microwave radio that should never be used if the signal is weak except for emergencies. The only safe way to keep it next to the body is on airplane mode. Cell phones are not toys and should not be used by children. If desperation sets in on a long car trip or something and you absolutely must distract a child, then put the phone on airplane mode before handing it to them.

Economic development is the basic target of governments and protection of the environment and public health is often underestimated. Can we continue down this road? Will we survive?

There are important trade-offs between development and health. Sustainability specialists like to refer to the triangle between health, environment and development. One theory holds that not until a society reaches $7,000 per capita income can it afford to invest in environmental issues. I do not accept this premise.

China and India today are full of midsize cities where people are choking in air pollution equivalent to smoking four to six packs of cigarettes a day and the water is unfit to drink. Middle-class people that can afford it install air cleaners in their homes that require more fossil fuels to run them so that they can live and breathe more safely. This is clearly a not a sustainable way of life.

The example of asbestos is especially noteworthy. Some companies went bankrupt dealing with compensation for the damage they had caused. Without doubt massive amounts of money will be required to fix the damage that is being created by thoughtless development without consideration of the impact on the environment. But so far no one has a way to fix damaged genes that can be passed on to future generations.
The green building movement around the world is very encouraging because it’s showing recognition of the importance of creating buildings that produce as much energy as they consume.

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