Friday, January 9, 2009

Bisphenol-A: Hysteria developing?

Bisphenol-A
In today's Straits Times Forum there is a letter written by a Ms Sai Siew Min entitled "Is the AVA Up To Date?". The letter addresses the writer's concern about the presence of bisphenol-A in baby bottles. Hmmmmm......

Bisphenol-A is a funny small molecule that has two arms, and is used in the manufacture of hard plastic bottles. The concern is that there is some data in animal studies that bisphenol-A at low levels can act as 'endocrine disruptors'. Bisphenol-A has some estrogenic properties, and can leach out from those hard plastic bottles, so mothers and mothers-to-be are legitimately concerned about the effects this may have on their babies.

There are quite a lot of reviews written recently about this that summarize the state of ignorance quite well:
Wikipedia
NIEHS-NIH
AVA

Truth be told, I have had a look at the data and I am not so convinced. It's one thing to look at endocrine changes in lab animals, and another thing to exprapolate those effects to the real world. Much of the data is kinda iffy anyway. My feeling is that AVA doesn't really have much to act upon other than a lot of emotive rants from various interest groups.

Also if you look at bisphenol-A, the effects are largely due to its estrogenic properties....and there are a lot of estrogenic substances all over the place, in our diet etc. Bisphenol-A isn't the only chemical that does this. Our diet contains naturally occuring estrogens such as bioflavonoids (fruits, veges, soya beans)...inodole-carbinols (cruciferous veges) to name some. An article here from the Texas A&M Univeristy and funded by the NIEHS estimates that the contribution of industrial estrogens probably amount to only about "0.0000025% of the daily intake of estrogenic flavonoids in the diet". The presence of these dietary estrogenic flavonoids have in fact, often been touted as being the reason for the 'health giving' properties of many fruits and vegetables.

Hysteria in the making...yeah, probably.

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