written by Ted Schettler, MD, MPH
As breast cancer awareness month ends with its primary emphasis on early detection I’ve been more interested in what we’ve learned about opportunities for prevention. Amidst all the pink ribbons and disagreements about optimal mammography scheduling an important theme seems to be finally taking hold. Although opportunities abound throughout life, breast cancer prevention begins in the womb.
This idea is not new. Twenty-five years ago Dimitri Trichopoulos proposed that breast cancer risk could originate in utero, influenced by maternal hormone levels. Later studies linked hormone and growth factor levels with populations of breast stem cells in umbilical cord blood—a plausible mechanistic connection to cancer risk. A 2011 analysis reported a nearly two-fold increased risk of breast cancer in daughters of women who took estrogenic diethylstilbestrol (DES) during pregnancy before 1971. This year, Barbara Cohn and colleagues reported that the highest maternal levels of the hormone-disrupting pesticide DDT during pregnancy were associated with a nearly four-fold increased risk of breast cancer in their daughters.
written by Ted Schettler, MD, MPH
CHE Science Director
updated September 25, 2015
Exposures to known and suspected risk factors for breast cancer begin early in fetal development and continue throughout life. Some relate to individual choices and lifestyle while others are encountered as an inevitable result of the way we design our communities and society more generally. In The Ecology of Breast Cancer I explored this multifactorial, multilevel complexity with an eye toward lessons learned from complex systems analysis while proposing practical interventions that may help prevent breast cancer and improve outcomes after diagnosis and treatment.
Risk factors are not experienced in isolation. They co-occur and interact in complex ways, creating system conditions in which breast cancer is more or less likely—in individuals and populations. When we attempt to take this complexity apart for purposes of research or decision-making, we often miss the properties that emerge from the whole.
The ten biggest news or research stories of the last quarter, in CHE’s view.
- Climate Change
Climate change continues to receive attention, from top-level activities to broad new investigations of health impacts.
- Pope delivers strong message on climate change in encyclical ‘Laudato Si’‘: In his much-awaited encyclical on the environment, Pope Francis offered a broad and uncompromising indictment of the global market economy, accusing it of plundering the Earth at the expense of the poor and of future generations. The encyclical: Laudato Si’.
- Obama Administration announces actions to protect communities from the health impacts of climate change at White House summit: The White House hosted a first-ever Summit on Climate Change and Health, featuring the Surgeon General, to stimulate a national dialogue on preventing the health impacts of climate change. See the speaker presentations and other videos on the White House blog.
- EPA carbon emissions plan could save thousands of lives, study finds: New carbon emissions standards that were proposed last year for coal-fired power plants in the United States would substantially improve human health and prevent more than 3,000 premature deaths per year, according to a new study. The study: US power plant carbon standards and clean air and health co-benefits.
- Climate change set to take major toll on economy and children’s health, experts warn: Researchers have only scratched the surface of the complex effects climate change will have on children’s health and the economy, panelists said at a climate change forum at the Woodrow Wilson International Center for Scholars.
- Cancer risk from chemical cocktail
Scientists looked at 85 chemicals not usually considered to have a role in causing cancer and found that 50 could play a part. The chemicals, at everyday exposure levels, were found to support mechanisms in the body that helped cancer to develop. They included chemicals found in items such as mobile phones, detergents and cooking pans, and pesticides used on fruits and vegetables. The study: Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.
- Weed killers, bee killers, sperm killers?
Research on a variety of pesticides is finding new effects and driving decisions to reduce use.
- Controversial insecticide use rises as farmers douse seeds: Since the early 2000s, US farmers have dramatically increased their use of controversial insecticides suspected of playing a role in the decline of pollinating insects, such as honeybees. The report: Large-scale deployment of seed treatments has driven rapid increase in use of neonicotinoid insecticides and preemptive pest management in U.S. field crops.
- Announcing new steps to promote pollinator health: In June 2014, President Obama issued a Presidential Memorandum directing an interagency task force to create a Strategy to Promote the Health of Honey Bees and Other Pollinators. In May, under the leadership of the US Environmental Protection Agency and US Department of Agriculture, the task force released its strategy. A summary and analysis: US plan to help bees focuses on more land.
- Pesticides on vegetables and fruit linked to lower sperm counts: A study found that those who consume fruits and vegetables that are known to have the highest quantity of pesticides have sperm counts that are 50 percent lower than those who eat the smallest amount of these items. The study: Fruit and vegetable intake and their pesticide residues in relation to semen quality among men from a fertility clinic.
- Health Canada looks to re-label weed killer Roundup: Health Canada announced on Monday that it will begin public consultations to update the product label to reduce human and environmental exposure. The consultation webpage: Consultation on Glyphosate, Proposed Re evaluation Decision PRVD2015-01
- France bans sale of weedkiller Roundup over UN fears it may be carcinogenic: French Ecology Minister Segolene Royal announced Sunday a ban on the sale of popular weedkiller Roundup from garden centres, which the UN has warned may be carcinogenic.
- Europe starts taking glyphosate off the shelves: Switzerland’s two largest retailers, Migros and Coop, have been listening to their customers and are already taking retail products containing glyphosate off their shelves. The Swiss retail withdrawal of glyphosate follows the announcement by German retail giant REWE that it will complete its withdrawal of glyphosate products from its 350 gardening outlets by September this year, at the latest.
- Chemical reactions: glyphosate and the politics of chemical safety: The IARC’s evaluation presents a dilemma for regulatory institutions. If they explicitly accept the validity of the IARC’s findings (and therefore acknowledge the choice-laden nature of safety evaluation) this might invite scrutiny and criticism of their own assessments, and regulatory decisions.
- Fracking/drilling and health
Breathing problems, cancer, lower birth weight, earthquakes and other effects inform policy decisions on fracking.
- Contamination and geologic effects
- Fracking chemicals detected in Pennsylvania drinking water: An analysis of drinking water sampled from three homes in Bradford County, Pa., revealed traces of a compound commonly found in Marcellus Shale drilling fluids, according to a study published on Monday. The study: Evaluating a groundwater supply contamination incident attributed to Marcellus Shale gas development.
- New study reveals potential Texas fracking contamination: A new peer-reviewed study reveals potential groundwater contamination in the Barnett Shale, a geological formation that underlies 17 counties in North Texas, including Denton County. But the cause is still under debate. The study: A comprehensive analysis of groundwater quality in the Barnett Shale region.
- Okla. science agency links quakes to oil: The state agency in charge of determining the cause of Oklahoma’s earthquake swarms announced today that it is “very likely” that the shaking has been caused by oil and gas activity. The statement: Statement on Oklahoma Seismicity.
- Health impacts
- Fracking produces air pollution that increases the risk of breathing problems and cancer, study claims: Researchers found that people living within three miles of a fracking site could be exposed to pollution levels that are significantly higher than the Environmental Protection Agency (EPA) deems safe. The study: Impact of natural gas extraction on PAH levels in ambient air.
- Lower birth weight associated with proximity of mother’s home to gas wells: Pregnant women living close to a high density of natural gas wells drilled with hydraulic fracturing were more likely to have babies with lower birth weights than women living farther from such wells, according to a University of Pittsburgh Graduate School of Public Health analysis of southwestern Pennsylvania birth records. The study: Perinatal outcomes and unconventional natural gas operations in southwest Pennsylvania.
- Fracking poses ‘significant’ risk to humans, says new EU report: A major new scientific study has concluded that the controversial gas extraction technique known as fracking poses a “significant” risk to human health and British wildlife, and that an EU-wide moratorium should be implemented. The report: Chemical Pollution from Fracking.
- New York makes fracking ban official: The Commissioner of the Department of Environmental Conservation announced the decision on Monday, saying a ban was the only reasonable alternative after years of exhaustive research and examination of the science and facts.
- DDT in pregnancy may raise breast cancer rates in daughters
The researchers observed a sizable, statistically significant association between in utero DDT exposure and risk of breast cancer in young women and a possible association with more aggressive tumors. These findings are the first ever reported for a prospective observation of a large pregnancy cohort. The study: DDT exposure in utero and breast cancer.
- US government recommends lower level of fluoride in water
For the first time in more than 50 years, the federal government has recommended lowering the level of fluoride in drinking water. The recommendation: U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries.
- Antibiotic use reduction
After decades of warnings, the issue of antibiotic overuse and resistance is gaining traction.
- White House opens ‘superbug’ summit, orders federal cafeterias to use meat raised with ‘responsible antibiotic use’: President Obama kicked off the day-long, mostly-closed-door meeting by directing federal departments and agencies to begin a process to buy meat and poultry raised with “responsible antibiotic use.”
- What Tyson’s pledge to stop using human antibiotics in chicken means for the future of superbugs: The Natural Resources Defense Council called the Tyson news a “tipping point for getting the chicken industry off antibiotics.” Yet when it comes to protecting against antibiotic resistance, critics say the change may be too little and too late.
- US chemical regulation reform gets boost as House passes TSCA rewrite
The US House of Representatives overwhelmingly approved a bipartisan bill that would update the nation’s industrial chemicals regulations for the first time in nearly 40-years. The bill—which would make it easier for the Environmental Protection Agency (EPA) to request new safety data on chemicals and regulate chemicals already on the market—takes a narrower approach than a competing bill in the Senate. See analyses of the bill: Who is looking out for the health of America’s children? House chemicals bill favors industry over families and The House passes TSCA reform!
- Parma consensus statement on metabolic disruptors
A multidisciplinary group of experts gathered in Parma, Italy, for a workshop hosted by the University of Parma, May 16-18, 2014, to address concerns about the potential relationship between environmental metabolic disrupting chemicals, obesity and related metabolic disorders.
- Improving population-wide nutrition
US agencies announced nutrition recommendations and a new ban.
- Scientific Report of the 2015 Dietary Guidelines Advisory Committee
The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meat; and low in sugar-sweetened foods and drinks and refined grains.
- FDA cuts trans fat in processed foods: The US Food and Drug Administration is taking a step to remove artificial trans fat from the food supply within three years. This step is expected to reduce coronary heart disease and prevent thousands of fatal heart attacks every year.
Ted Schettler, MD, MPH
Nahar MS, Liao C, Kannan K, Dolinoy DC. (2012), Fetal liver bisphenol A concentrations and biotransformation gene expression reveal variable exposure and altered capacity for metabolism in humans. Journal of Biochemical and Molecular Toxicology. doi: 10.1002/jbt.21459
This recently published study shows that the developing fetus is generally exposed to much higher levels of free (unconjugated) BPA than to conjugated BPA. In 78% of the samples, the ratio of free to conjugated BPA was greater than one with a mean of 6.91. (the authors undertook a number of efforts to avoid sample contamination, as described in their paper).
Previous studies have shown free BPA in amniotic fluid.
This adds to the growing evidence that the fetus is regularly exposed to free (active) BPA; that the chemical is not rapidly inactivated and excreted as in adults. Efforts to control BPA exposure in infants and children do nothing to protect the fetus…The fetus can only be protected by reducing/eliminating exposures in adults.
Animal studies show that fetal and perinatal exposures to BPA alter the development of the mammary gland and prostate, making them more likely to develop cancer later in life. Over 93% of Americans have measureable levels of BPA/BPA metabolites in their urine….i.e. exposures are ubiquitous. Based on the animal data, we continue to expose virtually the entire human population to a chemical that increases the risk of breast and prostate cancer. When will this stop?
Yes! Magazine’s Fall 2012 issue features an interview with Dr. Ted Schettler, CHE’s science director:
Talking with Dr. Ted Schettler is probably unlike any conversation you have had with your physician. Raise the topic of breast cancer or diabetes or dementia, and Schettler starts talking about income disparities, industrial farming, and campaign finance reform.
The Harvard-educated physician, frustrated by the limitations of science in combating disease, believes that finding answers to the most persistent medical challenges of our time—conditions that now threaten to overwhelm our health care system—depends on understanding the human body as a system nested within a series of other, larger systems: one’s family and community, environment, culture, and socioeconomic class, all of which affect each other.
Continue reading on the Yes! Magazine website.
In recognition of CHE’s 10th anniversary, colleagues who have been particularly instrumental to shaping CHE this past decade will be invited to write an introduction. This month’s introduction is by Ted Schettler, MD, MPH, CHE Science Director, Science Director of the Science and Environmental Health Network, and Coordinator of CHE’s Science Working Group.
Beginning a decade ago, CHE formed working groups with interests in specific aspects of environmental health science. Most were organized around health outcomes, since individuals and organizations frequently focus on a specific disease or disorder, often for very personal reasons, and it seemed logical to build on that structure.
Periodically, however, we come up against the limits of our taxonomies. For example, naming the diabetes-obesity spectrum working group was challenging from the beginning-it was once known as the metabolic syndrome working group—because of the common co-occurrence of insulin resistance, type 2 diabetes, obesity, cardiovascular disease, and lipid abnormalities, not only in individuals but also in populations. Moreover, midlife diabetes and obesity are themselves risk factors for cognitive decline, dementia, and certain kinds of cancer. But, since these conditions are so commonly mixed together, what is the disease? Does our routine use of the International Classification of Diseases coding system hinder our ability to see patterns and identify common environmental threads that create the conditions giving rise to the diseases of our time?
Ted Schettler MD, MPH
Science Director of CHE
and the Science and Environmental Health Network
Vitamin D plays an essential role in a number of biologic processes throughout the body. In addition to its long-recognized importance for bone health, vitamin D deficiency is increasingly acknowledged to be associated with a number of other diseases and disorders, including various kinds of cancer. A recently published study adds considerable support to yet another health impact—earlier age of menarche in otherwise healthy girls. If this finding holds up in future studies, the implications are profound.
If sunlight exposure is sufficient, adequate amounts of vitamin D are synthesized in the body. But many people, particularly those living in higher latitudes, are not exposed to enough sunlight to generate adequate stores. And, even in sunny places, skin cancer concerns limit sun exposure. Some foods are fortified with modest amounts of vitamin D in an attempt to address the deficiency. Nonetheless, vitamin D insufficiency remains extremely common in the general population. A recent report from the Institute of Medicine addresses this.