Beyond Pesticides Daily News Blog » Blog Archive Grandmother’s Exposure to Banned Pesticide DDT Increases Breast Cancer and Cardiometabolic Disorder Risk in Granddaughters
(Beyond Pesticides, April 22, 2021) Past exposure of mothers to the pesticide dichlorodiphenyl trichloroethane (DDT) during pregnancy may increase the risk of breast cancer and cardiometabolic disorders (eg, heart disease, obesity, diabetes) for up to three consecutive generations, according to a new study published in Cancer Epidemiology, Biomarkers & Prevention. While previous studies highlight early life or in utero exposure to DDT, increasing the risk of breast cancer later in life, this study is the first to note generational effects on grandchildren’s health. DDT continues to adversely affect the health of the US population nearly 50 years after its ban. However, this ban is not global, as many countries still use or manufacture the chemical compound. In addition, residues of DDT metabolite, DDE, food and water continue to be easily contaminated worldwide. Therefore, studies such as these emphasize the need to investigate how exposure to first generation pesticides can affect future health of generations to avoid adverse health outcomes, especially during sensitive developmental periods (i.e., in utero, infants / childhood). The researchers note, “Discovery of useful biomarkers of response to ancestral environmental exposures in young women may provide opportunities for breast cancer prevention.”
To assess the link between multi-generational health risks and exposure to chemicals, researchers used the Public Health Institute’s Child Health and Development Studies (CHDS). CHDS has been following a cohort of 20,000 pregnant women since the 1960s, exploring how diseases can be passed from one generation to the next. Researchers collected archived blood serum samples from pregnant grandmothers (F0) during and after pregnancy to measure o, p’-DDT, p, p’-DDT and p, p’-DDE concentrations. After adjusting for body mass index (BMI) and health effects in daughters (F1), researchers estimated granddaughter (F2) health outcomes, including waist circumference, weight, and height, using log-linear models. Health outcomes such as obesity and early periods are risk factors for breast cancer in later life.
The results show that the risk of obesity increases two to three-fold in granddaughter when grandmothers have high o, p’-DDT values, especially in grandmothers of average weight. There is also a positive association between grandmother o, p’-DDT levels and early menses in granddaughters, regardless of the grandmother’s BMI. (See “Pesticides and the Obesity Epidemic.”)
DDT, an organochlorine (OC) insecticide, has been widely used to control mosquitoes and in agriculture. However, a massive environmental movement spurred by Rachel Carson’s Silent Spring resulted in the banning of chemicals in 1972. DDT, and its major metabolite DDE, remains in the environment for decades after its discontinuation, with the U.S. Environmental Protection Agency ( EPA) has found chemical concentrations. that exceed acceptable levels. DDT / DDE are persistent organic pollutants (POPs) that are resistant to environmental degradation through chemical, biological and photolytic processes. These POPs persist in soil and water sediments, glacial meltwater runoff, U.S. national parks, and food webs. In addition, these compounds dissolve easily in body fat and linger for many years, adversely affecting the hormonal system, metabolic function and brain development. Exposure to DDT, as an endocrine (hormone) disruptor, increases the risk associated with diabetes, early menopause, decreased sperm count, endometriosis, birth defects, autism, vitamin D deficiency, non-Hodgkin lymphoma, and obesity. Previous studies indicate that exposure to DDE has multi-generational health effects on obesity and diabetes, with DDE uniquely increasing the incidence of breast cancer across generations. Climate change only threatens to exacerbate residual DDT / DDE exposure, as warming can affect chemical movement and concentration in the environment. Therefore, animals and humans can experience a weakened ability to tolerate those chemicals.
Many studies have long shown that exposure to DDT in childhood and in utero increases the risk of developing breast cancer later in life. However, studies show that many pesticides in use today and chemical contaminants play a role in a similar disease outlook, including breast tumor formation. Recent research from the Silent Spring Institute links 28 different EPA-registered pesticides to the development of mammary gland tumors in animal studies. Many of these chemicals are endocrine disruptors and thus affect breast cancer risk. Even household cleaners, most of which are pesticides, contain endocrine disrupting chemicals that increase the risk of breast cancer. In addition, long-term exposure to organophosphate (OP) pesticides increases adverse health and cancer risks, especially in women. Like DDT, exposure to other POPs such as per- and polyfluoroalkyl substances (PFAS) during pregnancy can increase cardiometabolic disorders such as obesity, diabetes and cardiovascular disease in offspring. Since DDT / DDE residues, pesticides currently in use and other chemical pollutants pollute the environment, exposure to these chemical mixtures can synergize to increase toxicity and disease effects.
Generational inheritance of health problems related to hereditary influences is a well-known phenomenon. However, this study is the first to demonstrate multi-generation health problems from exposure to DDT, a non-genetic factor. Therefore, exposure to pesticides poses as much of a health risk for several generations as hereditary diseases. An abundance of research links pesticide exposure and endocrine disruption with epigenetic (non-genetic influence on gene expression) effects. Fifteen years ago, a Washington State University study linked exposure to pesticides to the effects of multiple generations on male fertility in rodents. Exposure to glyphosate has, according to multiple studies, adverse effects over generations, with negligible observable effects on pregnant rodents, but serious effects on the next two generations. These effects include reproductive (prostate and ovarian) and kidney disease, obesity and birth defects. New findings suggest that exposure to the pesticide atrazine causes multi-generation resistance to the chemical in wasps by altering the composition of the gut bacteria. In addition, chemical by-products made during the manufacturing process of pesticides, such as dioxin, affect reproductive health for several generations.
Researchers note that previous studies of DDT exposure measured physical DDE concentration, as the metabolite stays in the body longer than the original chemical itself. However, this study finds that o, p’-DDT, rather than DDE, is the most sensitive biomarker for DDT exposure, indicating exposure during pregnancy many decades ago. The compound metabolizes much faster than the main ingredient for DDT (p, p’-DDT) which is broken down into DDE. In addition, studies find less potential for endocrine disruption associated with breast cancer risk for DDE compared to o, p’-DDT. Finally, the study’s researchers note that higher rates of obesity among granddaughters are most likely due to grandmother’s exposure to DDT rather than exposure to contemporary obesogenic chemicals through diet or other means. DDT-associated compounds are widely detectable in most of the US population, especially those with a colored (POC) community. It is therefore essential to understand the impact that these residues, and others like them, have on the future of human, animal and environmental health.
Study co-author and scientist at the Public Health Institute Barbara Cohn, Ph.D., emphasizes, “In conjunction with our ongoing studies of DDT effects in the generations of grandmother and mother, our work suggests that we should take precautions when use of other endocrine disrupting chemicals, given their potential to affect future generations in ways we cannot anticipate today … We don’t want to wait [for] the next three generations to find out which chemicals now cause breast cancer. “
It is essential to understand the effects that endocrine disrupting pesticides can have on the health of current and future generations. There is a lack of understanding behind the etiology of pesticide-induced diseases, including a predictable delay between exposure to chemicals, health consequences and epidemiological data. Therefore, legislators and regulators should consider taking a more precautionary approach before introducing these chemicals into the environment. With far too many diseases associated with exposure to pesticides in the US, reducing pesticide use is a critical aspect of protecting public health and addressing costs to local communities.
Learn about the effects of pesticides on human health by visiting the Beyond Pesticides’ Pesticide-Induced Diseases Database, which supports a shift from pesticide dependence. This database is a great resource for additional scientific literature documenting elevated rates of endocrine disruption, cancer, physical stress and other chronic diseases and conditions among people exposed to pesticides. Beyond Pesticides believes we need to mitigate the multigenerational effects of pesticides on human and animal health. By applying regenerative-biological methods and using the least toxic pest control, harmful exposure to pesticides can be reduced. Solutions such as buying, growing and supporting organic can help eliminate the extensive use of pesticides in the environment. Learn about the multi-generational effects of pesticides on our health in Beyond Pesticide’s Pesticides and You magazine. In addition, read more and help spread the word about the dangers pesticides pose to children through our fact sheet Do not mix children and pesticides.
Help Beyond Pesticides educate and build the movement that will protect people, animals and the entire environment for as long as it takes by attending the National Pesticide Forum this spring. Cultivating healthy communities will bring together expert scientists, farmers, policymakers and activists to discuss strategies to eliminate harm from the use of toxic chemicals in favor of non-toxic organic solutions. It begins with a pre-conference session on Monday, May 24, and continues every Tuesday from May 25, June 1, June 8, and ending June 15, 2021. Registration is open today and available from the web page at this link. It starts with us.
All unattributed views and opinions expressed in this piece are those of Beyond Pesticides.
Source: Cancer Epidemiology, Biomarkers & Prevention, Environmental Health News