No sooner had I laid out my case, again, (3200 Calories In 1945, 2640 Calories In 2010. But We Weigh More), that chemicals in our environment (and so, in our food) were likely a strong contributor to recent high rates of obesity, diabetes, heart disease, infertility, etc., because they act as endocrine disruptors, than The Endocrine Society came out with this report:
Executive Summary to EDC-2: The Endocrine Society’s Second Scientific Statement On Endocrine-Disrupting Chemicals, The Endocrine Society, 28 September 2015
The full Scientific Statement represents a comprehensive review of the literature on seven topics for which there is strong mechanistic, experimental, animal, and epidemiological evidence for endocrine disruption, namely: obesity and diabetes, female reproduction, male reproduction, hormone-sensitive cancers in females, prostate cancer, thyroid, and neurodevelopment and neuroendocrine systems. EDCs such as bisphenol A, phthalates, pesticides, persistent organic pollutants such as polychlorinated biphenyls, polybrominated diethyl ethers, and dioxins were emphasized because these chemicals had the greatest depth and breadth of available information. … A conclusion of the Statement is that publications over the past 5 years have led to a much fuller understanding of the endocrine principles by which EDCs act, including nonmonotonic dose-responses, low-dose effects, and developmental vulnerability.
By “comprehensive” they weren’t kidding. Their bibliography includes over 1300 articles.
The Executive Summary’s first author, Andrea Gore, a professor of pharmacology and toxicology at the University of Texas, said:
This has really been an emerging field where there is much stronger evidence now.
The endocrine system is a collection of glands all over the body that produce hormones, like insulin, that control metabolism, growth, sexual functions, nerve functions like sleep, depression, irritability and other moods. Just about every cell in our body is affected by these hormones, so the function of every cell/tissue/organ has the potential to be disrupted when these hormones go awry.
The concern is that, as the ES report explains:
- These chemicals can act at extremely low-dose concentrations.
- Our exposure to these chemicals can be chronic and lifelong.
- There are tens of thousands of chemicals in the environment that act as endocrine disruptors but that have not been tested for health effects.
It was 9 years ago that I first became aware of this link through my work in diabetes. This study found that the odds of having diabetes were 38 times higher for people with high blood levels of persistent organic pollutants (POPs) than for people with low levels. That was an unusual and extraordinarily high risk! I blogged about it here.
That study said:
Greater than 90% of POPs comes from animal foods in the general population without occupational or accidental exposures.
That was 9 years ago. That animal foods are our greatest source of exposure is even more true today because the use of these chemicals has increased.
Why animal foods? The reason for this, as I often explain, is two-fold. Endocrine disruptors are 1. often fat-soluble and 2. they bioaccumulate. So, there’s going to be more chemicals in fatty meat and dairy than on a fat-free tomato. This has been my beef with the EWG’s Dirty Dozen for years. They only address fruits and vegetables. They don’t even include grains like wheat which constitute the foundation of the American diet, and which have been found to contain pesticides and other contaminants at levels sometimes higher than produce.
This next excerpt is from the graduate textbook, Towards A Risk-Based Chain Control (Food Safety Assurance and Veterinary Public Health):
Foods of animal origin are the greatest source of human exposure to PCBs and dioxins.
Potential contaminats in feedstuffs include environmental contaminants such as the polychlorinated biphenols (PCBs), dioxins and heavy metals including mercury, lead, or cadmium.
Pastureland may [also] become contaminated with these industrial pollutants.
Contaminated fats or oils added either intentionally or unintentionall to manufactured feeds can be a source of dioxins and PCBs.
Fish oils or meal used as animal feed ingredients may contain high levels of contaminants if they are produced from fish grown in poluuted areas.
Foods of animal origin may become contaminated during processing.
Take another look at this graph of our weight over time. The light blue at the bottom is “overweight” and the dark blue is “obesity.” GMOs and their attendant pesticides (Roundup Ready) have been available since the 1980s, allowing pesticides to be sprayed directly on the food part of the plant.
The study of nutrition, going forward, will have to be concerned not only with the nutrients we want in food, but the chemicals we don’t.