Prenatal toxicity linked to immune dysfunctions in later life

May 4 2007

A Cornell researcher and his wife have conducted the first comprehensive review of later-life diseases that develop in people who were exposed to environmental toxins or drugs either in the womb or as infants.

They have found that most of the diseases have two things in common: They involve an imbalanced immune system and exaggerated inflammatory reactions (at the cellular level).

In an invited, peer-reviewed article on developmental immunotoxicity (DIT), published in a recent issue of Current Medicinal Chemistry, Rodney Dietert, professor of immunotoxicology at Cornell's College of Veterinary Medicine, and Janice Dietert of Performance Plus Consulting in Lansing, N.Y., found that almost all the chronic diseases that are associated with DIT share the same type of immunological damage.

The diseases linked to DIT include asthma, allergy, suppressed responses to vaccines, increased susceptibility to infections, childhood neurobehavioral conditions, autoimmunity, cancer, cerebral palsy, atherosclerosis, hypertension and male sterility.

Toxins that are known to cause developmental immune problems in fetuses and neonates, according to the Dieterts, include herbicides, pesticides, alcohol, heavy metals, maternal smoking, antibiotics, diesel exhaust, drugs of abuse and PCBs.

Antidotes to DIT, the researchers note, could come from a variety of sources, including herbal and fungal chemicals -- from mushrooms to clover -- which appear to have promise.

Two immune processes -- T helper (Th) cell balances and dendritic cell maturation -- are both compromised in ways that disrupt the regulation of inflammatory cell function, which leads to exaggerated inflammatory responses.

"Most therapeutic approaches have looked at specific disease outcomes from DIT, rather than focusing on the underlying immune dysfunction that creates the increased disease risk," said Rodney Dietert, who also presented his findings March 28 at the annual Society of Toxicology meeting in Charlotte, N.C. "Instead, we looked at the common immune dysfunction that is related to a host of diseases."

Knowing the most common immune dysfunction patterns from DIT allows researchers to consider more seriously those "medicinals with the capacity to restore inflammatory cell regulation, promote dendritic cell maturation and restore desirable Th balance that would be the most likely candidates to combat the problems resulting from DIT."

Focusing on studies of herbal and fungal chemicals, the Dieterts scoured the literature and found that some of the chemicals appear to be particularly promising when taken at appropriate doses. These include: Astragalus; Echinacea (purple coneflower); sang-hwang shiitake, reishi, maitake and snake butter mushrooms, black seed, Asian ginseng, milk vetch root, wild yam, Sophoro root and Greek clover (all of these also go by various other names).

In their paper, the Dieterts also list a multitude of substances that have been found to have "an uncertain impact" on DIT as well as several found to exacerbate immune dysfunction (including marijuana).

"We hope that these findings of persistent immune dysfunction from gestational exposure will provide encouragement for additional research. Furthermore, that researchers will look at these categories of medicines that have the possibility of correcting inflammatory and immune balance problems resulting from DIT rather than focusing solely on individual disease symptoms," Rodney Dietert said.

He noted that until recently toxin-testing guidelines predicted only risk in adults, but that the Environmental Protection Agency has announced it will issue new guidelines to take into account the increased immune sensitivity of fetuses and young children.