Bisphenol Controversy Continues

A preliminary study calls into question what is known about bisphenol A (BPA) exposure and how it is removed from the body. BPA is a chemical commonly used in hardened plastics and is often found in baby bottles, water bottles and eyeglass lenses.

Based on early evidence, researchers suspect that humans are primarily exposed to BPA from food and that the chemical is eliminated from the body in about 24 hours.

However, this latest study suggests that BPA may also be present in other sources and/or remain in the body’s fat tissues. The researchers analyzed data on 1,469 adults living in the United States from the U.S. Centers for Disease Control and Prevention (CDC)’s National Health and Nutrition Examination Survey (NHANES). The CDC researchers recorded the participants fasting BPA levels and collected dietary information. Although the participants fasted before having their BPA levels measured, they were allowed to drink water, black coffee and diet soda. 

The authors of this recent study, published in Environmental Health Perspectives, compared the participants’ BPA levels to the length of their fasting period. They hypothesized that people who fasted longer would have lower BPA levels. However, the researchers discovered that participants who fasted only had moderately lower BPA levels than those who had just eaten.

According to the authors, these results suggest that BPA may come from sources other than food, such as water. They also suggest that BPA may enter fat tissue, where it would be released more slowly.

However, the results of this study are limited and open to interpretation. Additional studies are needed to understand how BPA exposure occurs and how it is removed from the body.  

The U.S. Food and Drug Administration (FDA) maintains that BPA is safe, despite early evidence that may be associated with an increased risk of diabetes and heart disease. Canada banned BPA from plastic baby bottles in October 2008.

Comments

[Rich]

This reminds me of admonitions from friends about the dangers of re-using soft bottled-water bottles at the gym, which seems not to be an issue. But it’s the hardened-plastic, reusable kinds that do cause concern, precisely because of the possibility of BPA leaching from them. Not just Canada, but Europe, too, banned plastic products that contain BPA in children younger than age three, as did San Francisco (although the article says the FDA says BPA is safe). So perhaps this study’s participants were using such hardened-plastic containers to drink their water, and thus the surprisingly moderate (not low) levels of BPA found in the study? Worth looking into, I would think!

[VLN]

I wonder what their rational was on only allowing the subjects to drink water, black coffee and diet soda. I think the study would have more validity if they had everyone fasting because one person could have drank water, and the other diet soda, so this is not consistent with all the subjects and creates a confounding variable.

[rfn]

If BPA could have negative effects on a person's health, why don't they just eliminate it from being used? Would it cost a lot more to change the production of water bottles?

[E.F.]

I think that they are going to discover in the future that BPA is also carcinogenic. If they banned it from baby bottles it can't be good for any of us. Why didn't they ban it in adult products?

[Rachel]

How scary!! Imagine if this really had a significant affect on the rise of diabetes and heart disease! I also wonder if obese people retain more BPA since there's more fat reserves. How does that affect the body, if at all?

[Lindsey]

The researchers in this study definitely should have standardized the group to be able to drink only water or only some other beverage. Since BPA may stick around in fat tissue, that just provides us with more reason to exercise!

[Matt LT]

I think that we have to keep in mind that in the United States, heart disease and type 2 diabetes are so widely prevalent due to people’s lifestyle choices for the most part. BPA may be a contributor to a higher incidence of these disease states, but at the same time, we know there are other variables that contribute, such as lack of exercise. In order to properly correlate that increased risk of adverse health outcomes with BPA, a longitudinal study that tests for BPA more than just once. While BPA may not be good for us in excess, neither is too much sugar, fat etc… There is a lot of confounding variables in the trial that was published in JAMA in September 2008 on BPA, and think that people are really just looking for a scapegoat to blame for our health problems. Eat healthily and be active; I think this would be good advice for all.

Besides, if we are activating estrogen receptors (supposed mechanism of BPA) wouldn’t you expect some metabolic changes? Menstrual irregularities? Increased clotting?? I know we don’t know how BPA exactly affects the body, yet and we probably shouldn’t be submitting our children to it if we don’t know. Don’t you think these health problems in adult populations are multi-variable as opposed to BPA as the origin?

[Michelle D.]

This is one of the first studies I have encountered that correlates BPA levels with fasting length. Although I do see how the study strives to match the BPA decrease with food clearance over time, it also seems to ignore the other variables introduced by the dietary factors. For instance, black coffee, introduced in varying amounts may have a significant effect on increased metabolism. Diet soda, if caffeinated, may also have an effect on metabolism. It's an interesting study, and I look forward to hearing about further developments.

[Rita]

Until further research is done, there should be some sort of warning on water bottles and foods containing BPA. Perhaps it is safer to drink filtered water than bottled water!

[Adija]

Another study published in the Journal of America Medical Association found that there are increased urinary concentrations of BPA in patients with cardiovascular disease and diabetes, but these patients were not subjected to certain diets like that referred in the article. However, I believe our bodies naturally have the ability to slowly excrete any unwanted substance, and everybody’s system could react differently to that excretion. I guess what am trying to say is that first we need to identify the risk factors for greater toxicity of BPA and then advise that population on what needs to be done to reduce their risk levels.

[Ada]

Rachel, maybe obese people will be at a higher risk if they consume extremely higher quantities than usual. I guess it is easily excreted, but if there is a higher concentration than normal stored in fat tissues it may lead to detrimental effects.

[Mina]

Does anyone know if these study participants were asked to drink specific brands of water? There have been arguments that certain brands of water contain higher amounts of BPA.

[JBT]

This is very interesting. In fact, I think I really need to look into this some more! What I really don't understand is why they cannot eliminate this substance and use something else to make hardened plastics?

[Cathy. P]

The possible dangers of plastics do seem to be getting more press the past few years. I’m not sure exactly what has been learned from this recent BPA study. however, doesn’t it say results are open to interpretation? Still, I think more research is needed to determine the effect of bisphenol A on both infants and older age groups. If eventually BPA is known to be harmful, I wonder if products will simply carry a health warning though, rather than implement a ban.

[R.M.]

It's good to see a study done on bisphenol, and I hope more research is done to assess how dangerous this really is. Unfortunately, this study doesn't help too much since the presence of other variables could have affected the results. I just read some interesting information from this site: http://www.babystoxicbottle.org/. One study suggests that bisphenol can affect the development of babies. If this is true, it's scary to think that so many retailers carry baby bottles that are manufactured with high levels of bisphenol.

[Carol]

I used to reuse the same water bottle and just fill it up with water over and over again. Once I heard of the cancerous chemicals that are absorbed from the plastic of the bottle, I stopped doing that. But who is to say that from the time the water is bottled to the time of consumption, that the BPA hasn't already gotten into the water?

[Mabinu]

I came across this, and thought I share with all my bloggers at Natural Standard. Five ways to keep Bisphenol A (BPA) out of your food:

1.Buy tomatoes sauce in glass jars. This is because canned tomatoes sauces is likely to high BPA due to high acidity of the tomatoes, which causes chemical to leach from the can lining.

2. Consume frozen fruits or fresh fruits and vegetables instead of canned. Besides being BPA-free, fresh and frozen fruits and vegetables also have more nutrients.

3. Purchase beverages in plastic or glass bottles. Canned soda and juices usually have high BPA levels. With plastic or glass, you don’t have to worry.

4. Use powdered infant formula instead of ready-to-use liquid.

5. Always think of moderation. You don’t necessarily need to avoid all canned products. Try to consume less of those foods with BPA.

[YB]

What is safe to use nowadays? I've heard harmful effects of aluminum cans and now this about plastic bottles. Which is the lesser of the two evils?

[lara]

I think this study is rather ambiguous in their findings. If biphenol exits in sources like water, then is there a difference between tap water and bottle water? How about if tap water is boiled? Would that change the amount of exposed biphenol?

The measurement method is also not clear. According to the study, “people who fasted longer would have lower BPA levels. However, the researchers discovered that participants who fasted only had moderately lower BPA levels than those who had just eaten.” What is a moderately lower level, 20% or 50%? And to what level would a moderately lower BPA level be ok for the general consumers? I think if there is more distinct and precise parameters for the study, the results would have been more definitive.

[PK]

Thanks for the shopping tips, Mabinu! I will definitely keep that in mind when I go grocery shopping.

[Scott]

That is disturbing to hear that something so common as plastic may contain a dangerous chemical within it. If the results of a more valid study prove that the BPA in plastics is harmful, most everyone would be affected. It would be worthwhile to know the exact type and brand of fluids that the fasting subjects were allowed to consume in this study. I wonder if a more expensive drink would have less BPA and therefore, be less harmful.