Endocrine Disrupters: Should We Fear Mother Nature?

by Angela Logomasini on May 4, 2012 · 2 comments

in Environment, Features, Odds & Ends, Precaution & Risk

A recent article published in the The New York Times touts a new report that claims to have finally proven that trace exposures to man-made chemicals can disrupt human endocrine systems and cause health problems.  The report authors include a number of well-known activists/scientists, who have been making suspicious claims about so-called “endocrine-mimicking chemicals” for decades.

Their Report concludes: “Whether low doses of EDCs [endocrine-disrupting chemicals] influence certain human disorders is no longer conjecture, because epidemiological studies show that environmental exposures to EDCs are associated with human diseases and disabilities.”

The article is little more than a review of the literature, selectively pulling out scientific studies that show statistical associations between health effects and certain man-made trace chemicals. But associations do not prove cause-and -effect, and a collection of studies with largely inconclusive, and often weak, associations do not prove anything. The report suffers from many of the same methodological flaws that Dr. Richard Belzer recently identified in his review of the science employed by the National Toxicology Program for it Report on Carcinogens.

An article produced by toxicologist Michael A. Kamrin sheds more light on the issue:

In the late 1990s, a “low dose” hypothesis was proposed based on studies that purported to show that hormonally active environmental agents were causing a variety of effects, mainly reproductive and developmental, at “low doses.” The supporters of this hypothesis claim that traditional “high-dose” toxicity studies are not adequate to assess adverse effects from these hormonally active agents in that they do not detect effects that are occurring at “low doses.” In addition, it is claimed that these “low dose” effects are occurring at levels comparable to those to which humans are being exposed. These claims have been controversial and expert panels evaluated the evidence behind them in the early 2000s. Although these panels generally concluded that such “low dose” effects were not conclusively established, proponents of the “low dose” hypothesis assert that a large number of more recent studies now provide clear support for their hypothesis. This review carefully examines both recent and older studies that have been cited to support the “low dose” hypothesis, including their relevance for the human population. These include in vivo and in vitro laboratory studies as well as a very limited number of epidemiological investigations. Based on the evidence, it is concluded that these “low dose” effects have yet to be established, that the studies purported to support these cannot be validly extrapolated to humans, and the doses at which the studies have been performed are significantly higher than the levels to which humans are exposed.

In any case, if the green-activists were right about low- dose risks, wouldn’t we also see effects from much higher doses? Mother Nature releases far more potent “endocrine mimicking” substances on a regular basis–which are part of many foods we eat. And when it comes to hormonally active agents, potency and the level of exposure are what matters.

For example, soy and nuts naturally contain such substances at levels that are tens of thousands of times higher than levels from man-made chemicals and more potent. If such endocrine mimicking chemicals were a problem, these foods would be wreaking havoc on human health. But they don’t.  Instead, these “Superfoods” contribute to the fact that people are living longer, healthier lives than ever before.

Despite the hype, there is nothing to fear, not even from Mother Nature.

 

Matt May 5, 2012 at 9:45 am

The man-made chemicals are new-to-nature. They have different chemical structures, binding to completely different regulatory regions of the DNA, and epigenetically influencing gene expression in a completely different manner than estrogen-like compounds in nature.

The comparison (of levels of “these substances”) made in this article does NOT justify use of synthetic estrogenic compounds (because the compounds produce different expression patterns); it only affirms that natural estrogenic compounds found in edible plants are not harmful in moderation. In addition, natural estrogens are taken together with the ENTIRE matrix of phytochemicals/fiber/etc found in that plant – this plays a unique “symphony” of gene expression that the isolated compound would not produce (as man-made chemicals often are – in isolation, removed from the matrix of other substances they are meant to “perform” with).

This concept is illustrated in studies showing the contrast in antioxidant response between placebo, isolated Vitamin C, and blood orange juice – which showed that only the blood orange juice generated a protective effect on cells (not the vitamin in isolation). As an aside, this is why isolated vitamin studies continue to show no benefit to health – vitamins do not behave as drugs/new-to-nature molecules designed to produce a singular effect – the problem is with the studies.

To expand your understanding of these concepts, I invite you to investigate work in epigenetics by individuals such as Randy Jirtle, PhD from Duke, Michael Skinner, PhD from Washington State, and/or Moshe Szyf, PhD from McGill.

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