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  (Source: steadyhealth.com)
Bisphenol A is considered a toxic substance in some countries because of the hormone-like properties it possess

A new study shows that bisphenol A exposure could help cause a brain tumor called meningioma.

Bisphenol A (BPA) is an organic compound that is used to make epoxy resins, polycarbonate polymers and other plastics. It is considered a toxic substance in some countries because of the hormone-like properties it possess. Canada and the European Union have even banned it from being used in baby bottles.

Now, a new study from China has revealed that BPA could be a risk factor for meningioma brain tumors. They made this connection by studying 247 patients with meningioma and 258 patients with no cancer history. Each patient had their medical records and history collected for the sake of the study.

All patients were observed at the Union Hospital in Wuhan, China. The researchers would check the brain tumors with brain scans or biopsies while BPA levels were identified through urine samples.

All volunteers were placed into one of four groups, which were determined by the concentration of BPA levels in urine. The groups consisted of less than 0.53 ng/ml, 0.54-0.91 ng/ml, 0.92-1.69 ng/ml, and over 1.69 ng/ml. They determined whether increasing BPA levels in urine were linked to meningioma diagnosis.

According to the results, patients in the latter three groups with the higher BPA concentrations were 1.4 to 1.6 times more likely to be diagnosed with meningioma than those in the lowest BPA level group. The team also found that the association between the two remained consistent despite other factors like BMI, age and gender.

The study noted that this is the first time a link has been shown between BPA exposure and meningioma diagnosis.

Source: Environmental Health News



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Bad Science?
By petschska on 7/3/2012 12:10:31 PM , Rating: 2
The original paper is blocked by a paywall so I can't see the real details to vet this out. Does anyone else feel like this is questionable science?

First, this study shows a correlation, not a causation. What if all these people live next to a BPA and nuclear waste disposal facility. They also have meningioma. Just because their BPA levels are higher doesn't mean you can draw any conclusion about BPA. It's more likely it's the nuclear waste facility! BMI, age, and gender are great, but they are far from all the necessary variables that need to be examined to make a conclusion.

Secondly, this study was done performed on Chinese citizens, where environmental laws are not followed. Any number of carcinogens could have had this effect on these people.

I'm not trying to downplay BPA concerns. Chemicals need to be handled properly and safely. But I'd like to see good science backup our decisions when we restrict useful chemicals from our everyday products.




RE: Bad Science?
By ShaolinSoccer on 7/3/2012 2:21:07 PM , Rating: 2
Regardless, people shouldn't freeze or heat up water bottles. That plastic isn't rated for that type of exposure and could release chemicals into the water.


RE: Bad Science?
By geddarkstorm on 7/3/2012 2:26:27 PM , Rating: 2
From the tone, I don't think the study tries to make any claims about causation, just showing a correlation. Completely valid to do.

As from your other concerns,
quote:
All patients were observed at the Union Hospital in Wuhan, China
So the pool these patients come from is all from the same localized region, decreasing alternative effects as being factors in the correlation between rising BPA levels in urine and brain tumor incidence.

We've seen BPA do some nasty stuff in other studies, so this is definitely worth looking more into.


RE: Bad Science?
By xdrol on 7/12/2012 10:19:57 AM , Rating: 2
How is all subjects coming from the same region decrease the possible alternative effects?


RE: Bad Science?
By jtemplin on 7/5/2012 7:51:50 PM , Rating: 2
There is one major flaw with this work. EDIT: just saw the sourced page discusses what I was about to write about. keeping it brief.

The very crucial matter of the grouping of patients and associated statistical tests by a single urine test is quite flawed.

One snapshot of the amount of BPA onboard in these patients is almost completely useless in establishing BPA as a chronic factor or even a factor at all in these tumors. Evidence suggests that BPA is rapidly cleared from the body. If this is the case then to establish a biological relationship, the authors would have had to do a prospective/longitudinal design with frequent urine samples.

It is necessary to show that the meningioma patients were chronically exposed to higher BPA levels. They also need to show that the levels were high when the tumor was forming. Looks like their urine test is at time of diagnosis meaning they may have missed the important urine samples, potentially, by years.

An idea for longitudinal testing is that it be anchored around a meal like dinner. That way all patients will be in the same pharmacokinetic/dynamic state and differences in urine samples between subjects with identical BPA intake should be minimized. Given identical BPA intake, imagine someone being tested 5 hours after the BPA intake versus 1 hour. The 1 hour subject should look like they got way more BPA than the 5 hour.


Honest question
By Lord 666 on 7/3/2012 2:32:27 PM , Rating: 1
Is there BPA in soda cans? I've searched around and cannot find anything.

Thinking the acidic nature of soda and specifically diet soda (not to mention red bull and monsters) could be breaking down the lining.




RE: Honest question
By Smilin on 7/3/2012 2:40:45 PM , Rating: 3
There is not. Those are pure aluminum or steel (pepsi may have switched to aluminum by now..they've been steel for ages)

BPA is used for plastic manufacture. You'll find it in water bottles and especially in the coated lining of canned goods.

Also just fyi for no reason (I worked at Coke for a while):
Diet soda has an expiration of 90 days and will be pulled from the shelf after that time (the sweeteners degrade).
For non diet sodas they have a 1 year shelf life in cans, and a 90 day shelf life for plastic bottles. CO2 can leech through the plastic and they begin to get flat after a while.


RE: Honest question
By geddarkstorm on 7/3/2012 2:48:46 PM , Rating: 2
Oh wow, very interesting and thanks for the insight. It explains how diet sodas can get so nasty if they've been around for awhile. Never realized that was the source of it (haven't had any in ages).


RE: Honest question
By Solandri on 7/4/2012 1:25:33 AM , Rating: 2
Aluminum and steel cans all have a thin layer of plastic on the inside to protect them from corrosion. I do not know if this plastic contains BPA.

The reason for the plastic is that corrosion in water operates differently from corrosion in air. For aluminum in particular, when it corrodes in air, it forms a thin layer of aluminum oxide, aka corundum, aka rubies and sapphires. It's very hard, practically impenetrable, and does a great job protecting the rest of the aluminum from oxidation (why your aluminum foil sheets stay nice and shiny).

Underwater, it's a completely different story. The aluminum oxidizes with oxygen, and the new aluminum oxide molecule simply floats away in the water. No protective layer develops, and the corrosion continues unabated. So all metal cans which will hold a liquid have a very thin plastic liner on the inside, to keep the water from contacting the metal. (There are a few metals that won't corrode - e.g. gold, platinum - but this trait makes them so valuable in other uses that it's completely impractical to make cans out of them.)

http://cr4.globalspec.com/blogentry/9993/Soda-Cans...
http://www.biotele.com/hydrogen.htm


RE: Honest question
By gnac on 7/3/2012 4:19:42 PM , Rating: 2
There MAY be. Virtually every can (soda, beer, fruit, vegetable, soup, etc.) has a coating to protect the can from potential attack by the product contained and to protect the product from picking up metals from the can.

http://www.valsparpackaging.com/beverage.jsp

Years ago the linings DID contain BPA (as many of the coatings were epoxy based) - not sure of the formulations today.


Can we have a little comparison from this study?
By Kurz on 7/3/2012 9:50:16 AM , Rating: 2
What is the typical dose someone gets from drinking a liter of water per day from a BPA made water bottle.




By Smilin on 7/3/2012 10:04:22 AM , Rating: 2
I'm a bit more concerned about canned foods. Although some sunlight/heat can excacerbate the problem, water bottles just don't have a very long lifespan from fill to drink.

Canned foods are dunked in BPA for months or years.


By johnsmith9875 on 7/3/2012 11:12:55 AM , Rating: 2
Tomato sauces are particularly problematic because of the acidic nature.


By geddarkstorm on 7/3/2012 2:46:59 PM , Rating: 2
Here is a very good report on the matter: http://www.hc-sc.gc.ca/fn-an/securit/packag-emball...

Seems most daily intakes from canned foods are around:
quote:
HPFB has previously estimated the probable daily intake (PDI) of BPA for the general population from food packaging uses to be 0.18 µg/kg b.w from tested food cans in 1995, based on the results of food simulant extraction studies conducted on epoxy-lined cans.


That would be about 11 ug in a day, according to Canada.

Importantly, eating 5 mg of BPA results in a urine concentration of 180 ug/ml after 80 minutes, far above what's stated in this study, but it gives us an idea of the dosages these people may have been exposed to. Since they are at most 1.6 ng/ml, that would put them in the range of the daily dosage of BPA from canned foods. Of course, no idea how long after they were exposed that a sample was taken.

It's an interesting discussion. BPA may work at low doses as a sensitizer, making a person vulnerable to other carcinogens. The brain especially is vulnerable to this sort of insult.


I was never a big fan of bottled water
By johnsmith9875 on 7/3/2012 11:12:24 AM , Rating: 2
This confirms it. I use a glass container with an insulating shroud for my water bottle, the water just tastes better and you don't get any plastic funk.




By Starcub on 7/4/2012 9:47:38 AM , Rating: 2
IIRC BPA is classified under the "other" category of recycling codes. Specifically that means that plastic bottles with the recycle code number 7 might contain BPA. Also, last I looked into this, there were some minor/unsubstantiated concerns with chemicals used in some of the other classes and number 4 was considered the safest.


By superstition on 7/3/2012 11:13:47 PM , Rating: 2
Eden canned beans come with BPA-free liners. This is the only brand I know of. Here's an article from the company about this, and issues with tomato jars:

http://www.edenfoods.com/articles/view.php?article...




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