The chemical bisphenol A, known as BPA, has become familiar in the past decade, notably to parents searching for BPA-free bottles for their infants. Animal studies have found that BPA, which resembles the sex hormone estrogen, harms health. The growing brain is an especially worrisome target: estrogen is known to be important in fetal brain development in rodents. Now a study suggests that prenatal, but not childhood, exposure to BPA is connected to anxiety, depression and difficulty controlling behaviors in three-year-olds, especially girls.

More than 90 percent of Americans have detectable amounts of BPA in their urine; for most people, the major source of exposure is diet. BPA is a component of the resins that line cans of food and the plastics in some food packaging and drink containers, and the chemical leaches into the edible contents. Other sources of BPA exposure include water-supply pipes and some paper receipts.

Epidemiologist Joe M. Braun of Harvard University and his colleagues studied 240 women and their children in the Cincinnati area. The researchers collected urine samples from the mothers twice during pregnancy and within 24 hours of birth and from the children at ages one, two and three. BPA was detectable in 97 percent of the samples. They also surveyed parents about their kids’ behavior and executive functions—a term for the mental processes involved in self-control and emotional regulation.

The researchers found that the more BPA children were exposed to in the womb, the more anxious, depressed and hyperactive they were at three years old and the more difficulty they had con­trolling their emotions and inhibiting behaviors. The effects were most severe in girls. The team did not find a con­nection between the children’s behavior and their exposure to BPA after they were born, they report in the November 2011 issue of Pediatrics.

Determining the precise mechanisms behind BPA’s effect on behavior will require more work, Braun observes. BPA interferes with estrogen; in the brain, this action could affect the migration and survival of neurons, for example. “It is fair to say there is reasonable concern over BPA toxicity,” Braun says.

Luckily, reducing dietary exposure is possible. As reported last July in Environ­­mental Health Perspectives, 20 participants swapped their normal diet, which included canned and packaged foods, for a “fresh foods” diet, which did not. The dietary switch reduced the participants’ BPA levels by 66 percent after three days.

This article was originally published with the title How Packaged Food Makes Girls Hyper.

4 Comments

1. 1. Michael M 05:54 PM 3/16/12

   From the time scale of developmental problems the activity of BPA likely results in epigenetic changes.
   
   The chromosomes to begin exploring, if the symptoms consistently appear in females, would be obvious.
   
   Unless BPA and other environmentally insulting chemicals are removed from food and food packaging, banned utterly, DSM-V will have to include this new behavioral variation.
   
   It is disturbing to think that a number of abnormal behaviors may well be related to the explosion of food additives.
   
   Epigenetic effects, as some may know, can persist in children and grandchildren of those so affected.
   

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2. 2. scientific earthling in reply to Michael M 06:47 PM 3/16/12

   Think about your statement: The chromosomes to begin exploring, if the symptoms consistently appear in females, would be obvious.
   
   The substitute for bpa containing plastics contain other chemical endocrine disruptors. PET bottles that look like thin glass contain selenium.

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3. 3. northernguy 05:09 PM 3/17/12

   Let's see. Fetal exposure to BPA in molecular amounts produces behavior, in a incredibly small sample, that the authors think is inappropriate for little girls.
   
   Even though they can't see what the mechanism would be for such an effect, and they didn't even try to control for any other influence, they attribute it to BPA.
   
   Great science!

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4. 4. Dr Jane 02:44 AM 3/20/12

   Hi.
   
   It's possible that high levels of BPA in the mother is a symptom, not the cause.
   
   The sources of BPA in humans are commonly packaging from processed foods and beverages which may themselves contain many other additives. High BPA levels probably correlate with poor diet and nutrition, and with higher levels of caffeine, artifical sweetners, colours, and flavours, all of which some studies link causally to behavioural problems in children. Parents with poor social supports or poor educations may resort to these sorts of foods more often, and thus it may be that disadvantage, social isolation or parental neglect are responsible for some of the 3 year olds who were "more anxious, depressed and hyperactive" and who had "more difficulty... ...con­trolling their emotions and inhibiting behaviors".
   
   The sample is very small, and I'd not be surprised if higher-than-average BPA levels are also associated with other factors- (such as poor diet and socio-economic disadvantage) that are highly significant in parenting outcomes.
   
   Having said all that, it is self-evident that endocrine dispruptors and chemicals that mimic hormones might have dramatic effects upon fetal development and subsequent behaviour, or upon timing of puberty.
   
   Dr Jane.

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