Research & Education

How Environmental Toxins Affect Offspring

It is well-established in the scientific literature that long-term exposure to environmental toxins wreak havoc on our overall health, increase levels of oxidative stress, and adversely affect fertility, pregnancy and fetal development. However, a very recent study found that even very short-term visits to a severely polluted city can have a dramatic impact on health. Study participants who traveled to Beijing, China had up to 800% greater concentrations of air pollutants than they did in Los Angeles and experienced higher levels of oxidized fatty acids and changes in cardiovascular enzyme function associated with heart disease.

Acute and/or chronic exposure to toxic xenobiotics such as endocrine-disrupting chemicals, heavy metals, pesticides, and air pollution has been shown to contribute to sterility in both males and females. Not only does preconception exposure to and build-up of these harmful foreign toxins negatively impact the mother’s physiology but they also pose substantial hazardous health risks for the growing fetus. Research shows that maternal exposure to heavy metals and other chemicals causes harmful effects to the placental DNA and fetal umbilical cord as these toxins and metals have the ability to pass through the placental barrier. Furthermore, the environment of the uterus is shown to influence fetal telomere length at birth, which is crucial for determining “cellular function, aging, and disease susceptibility over the lifespan”.

A very recent animal study published in iScience found that maternal exposure to various forms of industrial pollution can diminish the health of the immune system in offspring and that damage can be passed down across multiple generations, weakening the body’s natural defenses against infectious agents. Epigenetics already shows us that our environment significantly influences our genetic expression, but also that the effects from the environments that our great-grandparents were exposed to are passed down to us and a part of our genome. The article states that “this multigenerational weakening of the immune system could help explain variations that are observed during seasonal and pandemic flu episodes” (i.e., why the annual flu vaccine works for some and not for others, or why some individuals become severely ill during pandemic outbreaks while others fight it off). 

In the study, pregnant mice were exposed to dioxin, a ubiquitous environmental pollutant that is a common by-product of industrial production, and due to bioaccumulation are increasingly detected in animal-based foods. When these exposed mice were inoculated with the influenza A virus, scientists observed a marked decrease in the synthesis and action of cytotoxic CD8+ T cells (i.e., white blood cells whose job is to defend the host against foreign invaders, such as bacteria and viruses). Not only was the impaired immune strength witnessed in the offspring of the mice who were exposed to the toxins, but also in the two subsequent generations following, and was more prominent in the female mice. The researchers in the study speculate that exposure to dioxin (and various other xenobiotics such as PCB) alters the instructions for genetic transcription because it binds to the aryl hydrocarbon receptor (AHR), an environment-sensing transcription factor that plays a vital role in immune system development and function.

Unfortunately, exposure to environmental toxins cannot be completely avoided, but there are ways to minimize exposure and counter their adverse effects. Dietarily, patients may consider choosing organic produce and grass-fed, grass-finished meats, pasture-raised poultry, and wild-caught fish whenever possible to minimize pesticide and toxin exposure. Additionally, patients that increase their intake of fruits and vegetables, and herbs and spices (or take nutritional supplements) that are loaded with antioxidant-rich phytonutrients such as quercetin, vitamin C, vitamin E, rutin, lutein, lycopene, and resveratrol, and curcumin may help bolster their defenses against oxidative stress caused by environmental toxins and synthetic chemicals. Avoiding toxic body care products and household cleaners and replacing them with natural ingredients is another great way to reduce the overall toxic load.