Chemicals May Play Role in Rise in Obesity

[Duppers]

Chemicals May Play Role in Rise in Obesity

By Elizabeth Grossman
Special to The Washington Post
Monday, March 12, 2007; A06

Too many calories and too little exercise are undeniably the major factors contributing to the obesity epidemic, but several recent animal studies suggest that environmental exposure to widely used chemicals may also help make people fat.

The evidence is preliminary, but a number of researchers are pursuing indications that the chemicals, which have been shown to cause abnormal changes in animals' sexual development, can also trigger fat-cell activity -- a process scientists call adipogenesis.

The chemicals under scrutiny are used in products from marine paints and pesticides to food and beverage containers. A study by the Centers for Disease Control and Prevention found one chemical, bisphenol A, in 95 percent of the people tested, at levels at or above those that affected development in animals.



http://www.washingtonpost.com/wp-dyn/content/article/2007/03/11/AR2007031100918.html

[meldroc]

1. Of course, the industries have already circled the wagons.

When I googled bisphenol A, the top of the search results was an industry astroturf/fluff site full of flowering articles talking about how safe bisphenol A is, how it's harmless to the environment, how responsible the industry is with it, etc.

Of course, even with reams of iron-clad evidence showing the harm from these chemicals it will take removing our current pResident from power, and decades of wailing on lawmakers before they even begin to force the industry to clean up its act.

[GreenPartyVoter]

2. I have long wondered what artificial junk in food has in the role of

the obesity epidemic, too.

[rebel with a cause]

7. I have been saying this for decades and told that I was only

making excuses. the obesity problem started when they started messing with our food supply and taking away the more natural stuff we had always ate.

I also said that there was something physically causing my gaining of weight when in the late 1970s I was walking around 10 miles a day, eating sparingly and gaining weight. The doctors would always say it was fluid, but they never bothered to diagnose what it was or to treat it. It seems that physicians (or anyone else) don't put much effort in treating poor people who have weight problems.

[SmokingJacket]

3. Interesting.

It has always struck me as weird that people suddenly became lazy and greedy in 1980 -- the year after which obesity rates started shooting up.

[Radical Activist]

4. Someday we're going to realize

that we've been slowly killing ourselves with all the chemicals and toxins we rely on for our modern society. I think what we realize now and is commonly known is only the tip of the iceberg.

[BadgerKid]

5. quick check of the literature

Looks like BPA has been extensively studied by Japanese researchers. BPA is relatively quickly biodegradable by several microorganisms and plants. There is evidence of toxicity. For example:

Toxicology. 2006 Jan 16;217(2-3):81-90. Epub 2005 Nov 9.Click here to read Links
Biodegradation or metabolism of bisphenol A: from microorganisms to mammals.
* Kang JH,
* Katayama Y,
* Kondo F.

"Toxicity and estrogenicity on BPA metabolites have been identified. Atkinson and Roy, 1995a and Atkinson and Roy, 1995b found that the BPA metabolite, bisphenol-o-quinone, could bind DNA in vitro and in vivo. From these results, they suggested that covalent modifications in DNA by in vivo exposure of BPA may be a factor in the induction of hepatotoxicity. Moreover, Yoshihara et al. (2001) suggested that the estrogenicity of BPA increases (two to five times) through its biodegradation by rat liver S9 fractions, microsomal and cytosolic fractions. The active estrogenic metabolite was confirmed to be 4-methyl-2,4-bis(p-hydroxyphenyl)pent-1-ene (MBP) (Yoshihara et al., 2004). A recent study using medaka (Oryzias latipes) suggested that MBP has higher toxicity on its early life stages and shows about 250-fold higher estrogenic activity when compared with BPA (Ishibashi et al., 2005). In addition, BPA glucuronide has lower estrogenicity than BPA. The estrogenicity of 5-hydroxy BPA is also less than that of BPA, but it is known as a weak estrogenic compound (Nakagawa and Suzuki, 2001 and Elsby et al., 2001a). The BPA sulfate shows no estrogenicity up to 1 mM, but an increase in levels of pS2 mRNA expression is found at a concentration of 1 μM of BPA (Shimizu et al., 2002).

7. Conclusions

BPA can be metabolized by many organisms from microorganisms to animals, but further studies of BPA metabolism on extensive organisms, especially, birds and invertebrates, are required. Though the metabolites of BPA can enhance estrogenicity or toxicity, generally, BPA metabolism by organisms leads to detoxication of BPA. However, the fact that BPA can be biodegraded or metabolized by organisms does not mean that BPA has no estrogenic or toxic effect on organisms. "

[KT2000]

6. It is a persistent chemical

it resides in the fat tissue so it will increase as you go up the food chain.
Nursing mothers pass it to their babies.