By Dr. Mercola
In the U.S., about 75 percent of men and 67 percent of women are now either overweight or obese. This has risen significantly from figures gathered between 1988 and 1994, when "just" 63 percent of U.S. men and 55 percent of U.S. women were overweight or obese.1,2
Complicating matters, research published in Obesity Research & Clinical Practice found that the same caloric intake and exercise program would result in a body mass index (BMI) that is about 5 pounds higher in 2006 than it would have been in 1988.3
In other words, in order to maintain the same weight as in 1988, today you'd need to exercise more and eat fewer calories. The results suggest "factors other than diet and physical activity may be contributing to the increase in BMI over time," but what factors, exactly?4
This remains to be seen, but increasing evidence suggests environmental chemicals, particularly endocrine-disrupting chemicals (EDCs) are playing a role.
Endocrine-Disrupting Chemicals Linked to Significant Disease and Dysfunction
Endocrine disruptors, a number of which are found in plastic products, electronics, cleaning products, and even food, are similar in structure to natural sex hormones such as estrogen, thereby interfering with their normal functions. As stated in a report by the Environmental Working Group (EWG):5
"There is no end to the tricks that endocrine disruptors can play on our bodies: increasing production of certain hormones; decreasing production of others; imitating hormones; turning one hormone into another;
… [I]nterfering with hormone signaling; telling cells to die prematurely; competing with essential nutrients; binding to essential hormones; accumulating in organs that produce hormones."
Recent research published in The Journal of Clinical Endocrinology & Metabolism further revealed that exposure to EDCs in the European Union are likely to contribute substantially to disease and dysfunction and result in about $209 billion in health and economic costs.6
Among the chemicals known to be EDCs are:
|Diethylstilbestrol||Polychlorinated biphenyls (PCBs)
|Bisphenol-A (BPA)||Dichlorodiphenyldichloroethylene (DDE)
|Organophosphate and organochlorine pesticides||Polybrominated diphenyl ethers (PBDEs)
The study further noted EDCs play at least a probable role in the following conditions:
|IQ loss and associated intellectual disability
||Attention-deficit hyperactivity disorder
|Childhood and adult obesity
||Prostate and breast cancers
|Cryptorchidism (undescended testicle)
||Mortality associated with reduced testosterone
|Male and female reproductive dysfunctions
How Computer Simulations May Make Chemicals Appear Safer Than They Really Are
As research mounts showing BPA's risks to human health and the environment, it remains largely unregulated in the U.S.
This lack of action in the face of apparent risk may be traced back to physiologically based pharmacokinetic (PBPK) modeling, which is a method of using computer simulations to measure the health effects of chemical exposures.
PBPK is commonly used by regulatory toxicologists for chemical risk assessments, but there are concerns about its accuracy.
While the computer models allow scientists to determine what concentrations of a chemical end up in certain organs, and how long they may take to exit your body, they reveal nothing about the chemical's effects.7 As reported by Independent Science News:8
"PBPK simulations made testing faster and cheaper, something attractive to both industry and regulators. But the PBPK model has drawbacks …
Many biologists say PBPK-based risk assessments begin with assumptions that are too narrow, and thus often fail to fully capture how a chemical exposure can affect health.
For example, a series of PBPK studies and reviews by toxicologist Justin Teeguarden of the Pacific Northwest National Laboratory in Richland, Wash., and his colleagues suggested that BPA breaks down into less harmful compounds and exits the body so rapidly that it is essentially harmless.
Their research began with certain assumptions: that BPA only mimics estrogen weakly, that it affects only the body's estrogen system, and that 90 percent of BPA exposure is through digestion of food and beverages.
However, health effects research has shown that BPA mimics estrogen closely, can affect the body's androgen and thyroid hormone systems, and can enter the body via pathways like the skin and the tissues of the mouth.
When PBPK models fail to include this evidence, they tend to underestimate risk."
BPA: The 'Poster Child' of Endocrine-Disrupting Chemicals
Bisphenol-A (BPA) was first created in 1891 by a Russian chemist. By the 1930s, it was found to mimic the effects of estrogen in the human body. Still, in the 1950s BPA found its way into industry, as a chemical that could produce strong, resilient and often transparent plastics.
BPA is also used to make BPA resins, which keep metal from corroding and breaking. As such, it now coats about 75 percent of cans in North America. The chemical is surrounded in controversy as research continues to build that it's detrimental to human health.
Yet, the BPA market was valued at over $13 billion in 2013, and sales are set to expand 5 percent annually. As of 2012, 10 billion pounds of BPA were produced worldwide, sales of which amount to tens of millions each day.9
Most Americans have BPA in their blood, usually in the range of 1 part per billion (ppb).10
This might seem like too miniscule an amount to cause problems — and that's just what regulators and chemical companies have long stated — but 'endocrine disruptors like BPA, which act like hormones, don't 'play by the rules,' says Patricia Hunt, a geneticist at Washington State University."11
According to Hunt, "exposure to low levels of BPA — levels that we think are in the realm of current human exposure — can profoundly affect both developing eggs and sperm."12
BPA has been linked to a number of health concerns, particularly in pregnant women, fetuses and young children, but also in adults, including:
| Structural damage to your brain
||Changes in gender-specific behavior, and abnormal sexual behavior
|Hyperactivity, increased aggressiveness, and impaired learning
||Early puberty, stimulation of mammary gland development, disrupted reproductive cycles, ovarian dysfunction, and infertility
|Increased fat formation and risk of obesity
||Stimulation of prostate cancer cells
|Altered immune function
||Increased prostate size and decreased sperm production
Much of the research on BPA has involved animals, leading skeptics (usually those in the chemical industry) to say the effects may not necessarily be the same in humans. But research involving humans has shown similar risks.
For instance, BPA from cans or plastic bottles can raise your blood pressure within just a few hours of ingestion.13 And in the NHANES study, published in 2010, adults with the highest levels of BPA in their urine were more than twice as likely to develop coronary heart disease as those with the lowest levels.14
According to Independent Science News:15
"To promote the idea that BPA is safe, the chemical industry routinely lobbies policymakers and 'educates' consumers. What has not been widely discussed, however, is how industry has backed PBPK studies that marginalized research showing risks from environmentally typical levels of BPA.
Many of these doubt-inducing studies have been conducted by researchers whose careers can be linked to the PBPK work done at Wright-Patterson. In published critiques, health effects researchers — among them Gail Prins and Wade Welshons — have detailed the many ways in which these PBPK models fail to accurately reflect BPA exposure."
Exposure to BPA, Phthalates Associated with Altered Gene Expression in the Placenta
EDCs like BPA and phthalates are thought to be particularly dangerous to pregnant women, fetuses and young children. According to NewHope360:16
"The increasing concern over the potential for exposure of environmental chemicals to the mother and baby to cause adverse health effects is ongoing, with epidemiological research linking exposure to some of these chemicals in pregnancy with adverse birth outcomes:
… [P]regnancy loss, preterm birth, low birth weight, congenital defects, childhood morbidity, obesity, cognitive dysfunction, impaired immune system development, asthma and early puberty."
Recent research from Harvard University researchers even linked EDCs including BPA and phthalates to altered gene function in pregnant women's placentas. In a study of 179 pregnant women, exposure to BPA and/or phthalates was associated with alteration of molecules that regulate genetic expression in the placenta.17 The changes in gene functioning could lead to altered growth and development of the fetus.
Toxic Levels of BPA May Be Found in School Lunches
BPA is found in air, household dust and water, but the primary source of exposure for most people is through their diet.18 BPA can leach from polycarbonate tableware, food storage containers, water bottles and baby bottles and the coatings of canned foods into your food and beverages.
Recent research by Stanford University researchers even revealed that children may be exposed to toxic levels of BPA via their school lunches. They analyzed meals based on U.S. school nutrition guidelines and potential BPA exposures from included canned and packaged food.19
The potential BPA exposures ranged from 0.00049 micrograms per kilogram of bodyweight (μg/kg-BW) a day for a middle school student with a low-exposure breakfast to 1.19 μg/kg-BW/day for an elementary school student eating lunch with high exposure potential.
This falls well below the U.S. EPA Oral Reference Dose of 50 μg/kg-BW/day, however animal studies suggest BPA may be toxic above 2 μg/kg-BW/day. According to the researchers:20
"Children, with their developing organ systems, are especially susceptible to hormone disruption, prompting this research to model the potential dose of BPA from school-provided meals … The single meal doses modeled in this research are at the same order of magnitude as the low-dose toxicity thresholds, illustrating the potential for school meals to expose children to chronic toxic levels of BPA."
Additionally, the potential exposure level from a school lunch cannot be considered in isolation since children may also be exposed to BPA from their meals at home and via other sources, further adding to their toxic load.
Why BPA-Free Products Are Not Always a Safe Solution
In response to consumer demand for BPA-free products, many manufacturers have switched to using a different chemical called bisphenol-S (BPS). But BPS appears to be just as toxic, if not more so, than BPA.
In 2013, researchers at the University of Texas Medical Branch discovered that even minute concentrations — less than one part per trillion — of BPS can disrupt cellular functioning. Metabolic disorders like obesity, diabetes, and even cancer, are potential ramifications of such disruptions.
Basically, while manufacturers are not lying by stating their products are "BPA-free," they're not necessarily telling the whole truth either. Many have simply traded one endocrine-disrupting chemical for another, and health-conscious consumers may be lulled into a false sense of security by the BPA-free label.
In all, there are 13 types of bisphenols and more than 100 known EDCs; a BPA-free label only means that one of those has been excluded. Deborah Kurrasch, Ph.D., assistant professor at the University of Calgary, Alberta, told Medscape:21
"'What we're finding is that BPA-free does not mean bisphenol-free or endocrine-disrupting-free,' she stressed … The manufacturers can replace molecules and not do any safety profile testing. It's completely legal. They don't have to disclose what they use, and they don't have to disclose whether it's safe,' she emphasized."
15 Tips to Reduce Your Exposure to Endocrine-Disrupting Chemicals
Although it's virtually impossible to steer clear of ALL potentially hazardous chemicals, you can certainly minimize your exposure by keeping some key principles in mind. Even if the government refuses to protect you from these types of chemicals, that doesn't mean you have to accept them as a consumer.
- Eat mostly fresh whole foods. Processed and packaged foods are a common source of BPA and phthalates — particularly cans, but also foods packaged in plastic wrap.
- Buy products that come in glass bottles rather than plastic or cans.
- Store your food and beverages in glass, rather than plastic, and avoid using plastic wrap. Use glass containers if heating food in your microwave, as heat tends to increase the release of chemicals from plastic. Be aware that even "BPA-free" plastics typically leach other endocrine-disrupting chemicals that are just as bad as BPA.
- Use glass baby bottles for your infants.
- Be careful with cash register receipts. If you use a store regularly, encourage the management to switch to BPA-free receipts. I shop at Publix for my food and when I called them about the receipts it turns out they had already switched. Nevertheless it is wise to limit your contact with all these receipts.
- Look for products that are made by companies that are earth-friendly, animal-friendly, sustainable, certified organic and GMO-free. This applies to everything from food and personal care products to building materials, carpeting, paint, baby items, furniture, mattresses and more.
When redoing your home, look for "green," toxin-free alternatives in lieu of regular paint and vinyl floor coverings, the latter of which is another source of phthalates.
- Choose toys made from natural materials to avoid plastic chemicals like phthalates and BPA/BPS, particularly for items your child may be prone to suck or chew on.
- Breastfeed your baby exclusively if possible, for at least the first year (as you will avoid phthalates exposure from infant formula packaging and plastic bottles/nipples).
- Use natural cleaning products, or make your own.
- Switch over to organic toiletries, including shampoo, toothpaste, antiperspirants and cosmetics. EWG's Skin Deep database can help you find personal care products that are free of phthalates and other potentially dangerous chemicals.22
- Replace your vinyl shower curtain with a fabric one.
- Replace feminine hygiene products (tampons and sanitary pads) with safer alternatives. While most ingredients in feminine hygiene products are undisclosed, tests suggest they may contain dioxins and petrochemical additives.
- Look for fragrance-free products; phthalates are often used to help the product hold its fragrance longer. Artificial fragrance can also contain hundreds — even thousands — of potentially toxic chemicals. Avoid fabric softeners, dryer sheets, air fresheners, and scented candles for the same reason.
- Check your home's tap water for contaminants and filter the water if necessary. You may also want to use an alternative to PVC pipes for your water supply.
- Teach your children not to drink water from the garden hose, as many are made with phthalate-containing plastics.