Why Hasn’t Bisphenol A (BPA) Been Banned Completely?

“The number of new chemicals is increasing exponentially, with approximately 12,000 new substances added daily…”—yet data aren’t available on the hazards of even some of the high-volume chemicals. Bisphenol A (BPA) is one of the highest volume chemicals, with billions of pounds produced each year. Studies have raised concerns about its possible implication in the cause of certain chronic diseases, such as diabetes, obesity, reproductive disorders, cardiovascular diseases, birth defects, chronic respiratory diseases, kidney diseases, and breast cancer. Given this, BPA is the topic of my video Why BPA Hasn’t Been Banned.

A new study on the health implications of BPA comes out nearly every week. BPA was first developed over a hundred years ago as a synthetic estrogen, but it wasn’t until the 1950s that industry realized it could be used to make polycarbonate plastic, and “BPA rapidly became one of the most produced and used chemicals worldwide, even though it was a recognized synthetic estrogen” with hormonal effects. About a billion pounds are also used to line food and beverage cans, especially for tuna and condensed soups.

Today, nearly all of us, including our children, have BPA in our bodies, but not to worry: The government says up to 50 µg/kg per day is safe. Even those working in Chinese BPA factories don’t get exposed to more than 70 times lower than that so-called safety limit. Why then did exposure seem to affect male workers’ sperm counts? In the United States, the general population gets less than a thousand times lower than the safety limit, yet, even at those incredibly low doses, we still seem to be seeing adverse effects on thyroid function, weight control, blood sugar control, cardiovascular disease, liver function, and immune function. Indeed, “[t]he fact that there are significant adverse effects in populations exposed to BPA at concentrations [thousands of] times lower than the TDI [tolerable daily limit]…indicates that the safe exposure to BPA may be much lower than previously thought in humans.” Despite this, the limit hasn’t been changed. BPA has been banned from “baby bottles and sippy cups,” but nearly unlimited doses are still apparently okay for everyone else. What’s the disconnect?

It has to do with the fascinating world of low-dose effects of hormone-disrupting chemicals. “For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of ‘the dose makes the poison’”—that is, the concept “that lower exposures to a hazardous compound will therefore always generate lower risks.” Indeed, that is the core assumption underlying our system of chemical safety testing. Researchers start giving animals in laboratories a super-high dose and then keep lowering the dosage until whatever adverse effects that had occurred disappear. Then, they add a safety buffer and assume everything below that dose should be okay, assuming a straight line showing the higher the dose, the higher the effect. However, hormone-disrupting chemicals can have all sorts of curious curves. How is it possible that something could have more of an effect at a lower dose?

A study was done to see whether BPA suppressed an obesity-protective hormone in fat samples taken from breast reduction and tummy tuck patients. At 100 nanomoles of BPA, hormone levels were no lower than they were at 0nM of BPA. And, since most people have levels between 1 and 20, BPA was considered to be safe. But, although there was no suppression at 0 and no suppression at 100, at the levels actually found in people’s bodies, BPA appeared to cut hormone release nearly in half.

As the world’s oldest, largest, and most active organization devoted to research on hormones concluded, “even infinitesimally low levels of exposure—indeed, any level of exposure at all—may cause [problems].” In fact, it may come to nearly $3 billion in problems every year, counting the estimated effects of BPA on childhood obesity and heart disease alone. There are alternatives the industry can use. The problem, though, is that they may cost companies two cents more.


Related videos about BPA include BPA on Receipts: Getting Under Our Skin and Are the BPA-Free Alternatives Safe?

 BPA isn’t the only problem with canned tuna. Check out:

What can we do to avoid endocrine-disrupting chemicals? See, for example, Avoiding Adult Exposure to Phthalates and How to Avoid the Obesity-Related Plastic Chemical BPA.

Alkylphenols are another group of endocrine-disrupting chemicals. To learn more about them, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

How to Lower Phthalate Exposure Through Diet

Phthalates are hormone-disrupting plastics chemicals linked to a number of adverse health effects, such as disturbing infant and child development, and, in adults, may affect reproductive health in men and endometriosis in women, and is associated with increased abdominal fat in both. “Given the increasing scientific evidence base linking phthalate exposure with harmful health outcomes, it is important to understand major sources of exposure,” which I discuss in my video What Diet Best Lowers Phthalate Exposure?.

What is the most major exposure source? Diet. If you have people stop eating for a few days, you get a significant drop in the amount of phthalates spilling out in their urine. One can only fast for so long, though. Thankfully, we can see similar drops just from eating a plant-based diet for a few days, which gives us a clue as to where most phthalates are found.

The highest levels are found in meats, fats, and dairy. Poultry consistently comes out as being the most contaminated across the board with some of the highest levels ever reported, though there are geographic exceptions. In the United Kingdom, for example, fish came out worse than poultry, and, in Belgium, nothing appears to beat out reindeer meat in terms of contamination. In the United States, though, it is poultry, and the finding that egg consumption is also significantly associated with phthalate levels “suggests that chickens themselves may be contaminated” and not just arise from the plastic they’re wrapped in at the store.

The same might not be true with dairy, however. Realizing that these chemicals may be harmful, researchers in Seattle took ten families and randomized them into a five-day complete dietary replacement with fresh organic foods without any packaging. Nothing touched plastic. Organic milk was delivered in glass, and even the crates used to carry the food were wooden instead of plastic. This was like a fasting study to see what role eliminating processed foods would have on lowering phthalate levels because not everyone wants to switch to a plant-based diet—or stop eating completely. In my video, I show a chart depicting where the families started at baseline before changing their diet and where they were a week after the experiment, once again back on their baseline diet. What happened in the middle? When eating fresh and organic food, their phthalate levels went up, “a dramatic and unexpected increase in one of the most toxic phthalates—and not just by a little: It was like a 2000 percent increase. So the researchers tested all the foods. One of the spices was off the chart, and so was the dairy. Most of the phthalates apparently don’t come from the cow, however; they come from the tubing. If you milk cows by hand (which even the Amish don’t do anymore) the levels of phthalates in the milk are low, but if the same cows are milked by machine, the milk picks up phthalates from the tubing. As such, the final levels may depend more on the tubing than on what the cows are fed.

We’re not sure where the chickens are getting contaminated with phthalates, though. While that study was done on adults, we learned more recently where our kids may be getting it. Researchers found pretty much the same thing: mostly meat, including poultry and fish. Again, poultry appeared to be the worst, while soy consumption was associated with significantly lower levels. But what kind of exposure are we talking about? Researchers calculated what may be typical exposures for infants, teens, and women. How do these data compare with current guidelines? The U.S. Environmental Protection Agency’s reference dose, which is like the maximum acceptable threshold, is 20 µg/kg-day, based on liver risk. Europe places their maximum daily intake for testicular toxicity at 50 µg/kg-day. So a typical infant diet exceeds the EPA’s safety level, “while a diet high in meat and dairy was over this threshold by approximately four times. For adolescents, a diet high in meat and dairy also exceeded the EPA’s reference dose.” Indeed, diets high in meat and dairy consumption resulted in a two-fold increase in exposure. And “[a]ll diets for all groups exceeded the allowable daily intakes (ADI) derived by the US Consumer Product Safety Commission” for problems with sperm production, while diets high in meat and dairy consumption may exceed the allowable intake for risk of reproductive birth defects as well.


For more information on dietary sources of phthalates, I encourage you to watch both Chicken Consumption and the Feminization of Male Genitalia and Lowering Dietary Antibiotic Intake. Diet isn’t the only way one can be exposed internally, though. See my video Avoiding Adult Exposure to Phthalates, which discusses the risk in both children’s and adult toys.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

The Food Safety Risk of Organic versus Conventional

The stated principles of organic agriculture are “health, ecology, fairness, and care,” but if you ask people why they buy organic, the strongest predictor is concern for their own health. People appear to spend more for organic foods for selfish reasons, rather than altruistic motives. Although organic foods may not have more nutrients per dollar (see my video Are Organic Foods More Nutritious?), consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Food safety-wise, researchers found no difference in the risk for contamination with food poisoning bacteria in general. Both organic and conventional animal products have been found to be commonly contaminated with Salmonella and Campylobacter, for example. Most chicken samples (organic and inorganic), were found to be contaminated with Campylobacter, and about a third with Salmonella, but the risk of exposure to multidrug-resistant bacteria was lower with the organic meat. They both may carry the same risk of making us sick, but food poisoning from organic meat may be easier for doctors to treat.

What about the pesticides? There is a large body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson’s, Alzheimer’s, and ALS, as well as birth defects and reproductive disorders—but these studies were largely on people who live or work around pesticides.

Take Salinas Valley California, for example, where they spray a half million pounds of the stuff. Daring to be pregnant in an agricultural community like that may impair childhood brain development, such that pregnant women with the highest levels running through their bodies (as measured in their urine) gave birth to children with an average deficit of about seven IQ points. Twenty-six out of 27 studies showed negative effects of pesticides on brain development in children. These included attention problems, developmental disorders, and short-term memory difficulties.

Even in urban areas, if you compare kids born with higher levels of a common insecticide in their umbilical cord blood, those who were exposed to higher levels are born with brain anomalies. And these were city kids; so, presumably this was from residential pesticide use.

Using insecticides inside your house may also be a contributing risk factor for childhood leukemia. Pregnant farmworkers may be doubling the odds of their child getting leukemia and increase their risk of getting a brain tumor. This has led to authorities advocating that awareness of the potentially negative health outcome for children be increased among populations occupationally exposed to pesticides, though I don’t imagine most farmworkers have much of a choice.

Conventional produce may be bad for the pregnant women who pick them, but what about our own family when we eat them?

Just because we spray pesticides on our food in the fields doesn’t necessarily mean it ends up in our bodies when we eat it, or at least we didn’t know that until a study was published in 2006. Researchers measured the levels of two pesticides running through children’s bodies by measuring specific pesticide breakdown products in their urine. In my video, Are Organic Foods Safer?, you can see the levels of pesticides flowing through the bodies of three to 11-year-olds during a few days on a conventional diet. The kids then went on an organic diet for five days and then back to the conventional diet. As you can see, eating organic provides a dramatic and immediate protective effect against exposures to pesticides commonly used in agricultural production. The study was subsequently extended. It’s clear by looking at the subsequent graph in the video when the kids were eating organic versus conventional. What about adults, though? We didn’t know… until now.

Thirteen men and women consumed a diet of at least 80% organic or conventional food for seven days and then switched. No surprise, during the mostly organic week, pesticide exposure was significantly reduced by a nearly 90% drop.

If it can be concluded that consumption of organic foods provides protection against pesticides, does that also mean protection against disease? We don’t know. The studies just haven’t been done. Nevertheless, in the meantime, the consumption of organic food provides a logical precautionary approach.

For more on organic foods:

For more on the infectious disease implications of organic versus conventional, see Superbugs in Conventional vs. Organic Chicken. Organic produce may be safer too. See Norovirus Food Poisoning from Pesticides. Organic eggs may also have lower Salmonella risk, which is an egg-borne epidemic every year in the US. See my video Who Says Eggs Aren’t Healthy or Safe?

More on Parkinson’s and pesticides in Preventing Parkinson’s Disease With Diet.

Those surprised by the California data might have missed my video California Children Are Contaminated.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: