Estrogens are often called female sex hormones, but they are also found in men. Chemicals are said to have estrogenic activity (EA) when they bind to and activate estrogen receptors in cells. Estrogen receptors are designed to bind to natural estrogens made in the body but are also able to bind to thousands of other chemicals (such as BPA) with similar effects. An analogy for EA receptors is a loose lock where thousands of chemical keys will likely fit.
Endocrine disrupting chemicals (EDCs) are chemicals that mimic (or block) the action of hormones such as estrogens, androgens, and thyroxins. By far the most common form of hormonal activity in EDCs is EA. Several thousand xenobiotic chemicals are suspected to have EA. The most widely publicized EDC having EA is bisphenol-A (BPA), used to make (and released from) polycarbonate containers, can liners, and other products. Other examples of EDCs having EA are parabens in cosmetics and drugs, alkyl-phenols in soaps and paper products, and phthalates in many soft plastics. In fact, these and many other EDCs leach into the environment from a variety of consumer packaging products, foods, beverages, cosmetics, and personal care goods and can be consumed by people or pollute our environment.
While some chemicals having EA occur naturally in the body & in some foods, many scientific studies have shown that significant health problems can occur when additional amounts of xenobiotic EDCs are ingested. Numerous articles in scientific journals published over many years have reported that chemicals having EA can produce higher rates of some cancers, early puberty in females, diminished fertility, obesity, behavioral disorders, birth defects, & many other health disorders. This is an active research area, where scientists are trying to better understand the scope & magnitude of the health risks.
The fetus, newborn, or young child is especially vulnerable to trace amounts of these chemicals. Synthetic chemicals with EA are clearly a significant hazard to be avoided when possible for most people.
Removing BPA & few other widely publicized EDCs does not address the other thousands of potentially harmful chemicals having EA that could leach from plastics & other materials into the food & water we consume every day. This is why current legislative attempts to solve this problem by banning chemicals having EA one at a time – BPA, for instance — are not an effective solution. A recent peer-reviewed study showed that over 90 percent of BPA-free products & materials tested were positive for EA.
Avoiding plastics to eliminate EA exposure does not work. Colorants, additives, inks, processing aids, silicones, latex, and many other materials can still have EA. In addition, metal bottles can have liners that leach chemicals with EA. Glass, when not contaminated during processing, can be free of EA but rarely comprises a complete product. For example, glass may be used with an estrogenic silicone nipple, plastic anti-colic device, and rubber valve. Any of these materials, including plastic, can (and should) be made EA-free so that the entire finished product is EA-free.
We believe consumers should preferentially buy certified EA-free products. Consumer demand will quickly change markets from one-at-a-time chemical-by-chemical avoidance (e.g., BPA-free, phthalate-free, or paraben-free) to the comprehensive solution of EA-free much faster than legislative regulations (e.g., banning all chemicals with EA from use in consumer products). In the past, consumer safety demands led to retailers & manufacturers eliminating lead in most of children's products well before any legislation. More recently, consumers drove markets to quickly move away from the use of BPA in baby bottles, water bottles, and food storage years before the FDA issued vague & inconsistent warnings about this chemical.