Candace Waynick, RD LD
October 24, 2011
NUTN 507: Seminar

 Discuss the synthetic and legal history of
Bisphenol A (BPA)
 Describe uses of BPA and BPA containing products
 Discuss harmful effects of exposure to BPA and controversial methods of testing
 Describe the role of dietitians to minimize public health risks associated with BPA

 2 phenol compounds and 1 acetone
 Recognized for estrogenic properties in
1930’s by Edward Charles Dodd searching for the “mother substance” (synthetic estrogen)
 In the 1950’s, BPA is used to synthesize epoxy resins and polycarbonate plastics
 Superiority to glass and steel
Vogel 2009
Braun et al 2011
Biello 2008
Image: Wikipedia

 BPA is a monomer in synthesis
 Products:
 Protective coatings of medical equipment, piping, steel drums, and interior of food/beverage/liquid infant formula cans
Vogel 2009
Groff 2010
US FDA Update 2010
Taylor 2011
Image: http://news.consumerreports.org/a/6a00d83451e0d569e20120a69fcb0e970c-800wi

 Hard plastic formed when BPA is polymerized
 Products:
 Electronics, safety equipment, automobiles, food containers, plastics with recycling code # 7, intravenous tubing, dental sealant, reusable water and baby bottles
Vogel 2009
Groff 2010
US FDA Update 2010
Image: http://www.pacebutler.com/images/recycle/plastic-recycling-symbols-7.jpg

 Also contains BPA causing transdermal exposure
 Products:
 Sales receipts, cigarette filters, lottery tickets, fax paper, children’s books, and recycled paper products
Groff 2010
US EPA DRAFT 2011
Braun 2011
Taylor 2011
Image: http://www.bikudo.com/preview/292638.jpg

 Monomers of BPA can hydrolyze and leach into foods or liquids
 Accelerated by:
 High temperatures
 Acidic or basic conditions
 Damaged surfaces
 Le et al study
 Exposure to
100
｡
C (new and used PC water bottles) allowing 24 hrs to cool to room temperature
 Results: 15-55 fold increase in those exposed to
Groff 2010 heat versus room temperature water only
Braun et al 2011
Biello 2008
Le 2008

 1958- FDA approves BPA as indirect food additive
 Safety determined by toxicity, not carcinogenicity
 1977- National Cancer Institute (NCI) initiated 1st carcinogenesis study of BPA due to increased production
 Responsibility of program passed to the National
Toxicology Program (NTP) during 2 year study
 1988- Environmental Protection Agency (EPA) defines safe exposure levels to BPA as 50 micrograms/kg body weight
Vogel 2009
Shaw 2008

 Endocrine system disruption
 Cancer
 Obesity
 Cognitive and behavior impairment
 Cardiovascular Disease
(CVD)
 Type 2 Diabetes (DM2)
 Asthma
 Liver enzyme abnormalities
Shaw 2008
Ballard 2010
Image: http://bpafreewaterbottlespro.com/wp-content/uploads/2011/08/bpa-health-risks.jpg

 BPA is an endocrine-disrupting compound
(EDC)
 An exogenous agent that interferes with synthesis, secretion, transport, metabolism, binding, action, or elimination of natural bloodborne hormones that are present in the body and are responsible for homeostasis, reproduction, and developmental processes.
Bourguignon et al 2010

 Moriyama et al (2002) show BPA inhibiting thyroid hormone receptor (T
3
)-mediated transcription by acting as an antagonist
 Ramos et al (2003) exposed rats to BPA in utero indicating prenatal exposure induces transient and permanent age-dependent alterations in the male reproductive axis at different levels
Moriyama et al 2002
Ramos 2003
Image: http://electiondebates.com/images/stimulus-pix/rats.png

 Song et al (2002) demonstrate BPA inducing
NR4A1 gene expression (responsible for activating steroidogenesis) in mouse testicular cells
 Akingbemi et al (2004) actually show the opposite with low doses of BPA showing an inhibitory effect on testicular steroidogenesis
Song et al 2002
Akingbemi et al 2004

 Lang et al use NHANES data to show higher BPA urine levels associated with increased prevalence of CVD, DM2, and liver-enzyme abnormalities
Lang et al 2008
US EPA DRAFT 2011
Image: http://www.online-diabetes-information.com/wp-content/uploads/2011/03/diabetes-heart-disease2.jpg

 Higher BPA concentrations reflective of higher food intake per pound of body mass
 Predominant sources:
 Fetus- shown to cross the placenta
 Infants- breast milk, canned infant formula, and baby bottles
 NICU infants exposed to higher levels due to intensive medical interventions
 Children- canned food and beverages and school lunches
Groff 2010
Lang et al 2008
Bourguignon et al 2010
US EPA DRAFT 2011
Image: http://www.sequoiapediatricgroup.com/images/nicu_baby.gif

 Prenatal exposure associated with aggression and hyperactivity in 2 year old children
 Delayed breast development with higher BPA concentrations
 More sensitive to adverse outcomes due to exposure during development of neurological and endocrine systems
US EPA DRAFT 2011
Bourguignon et al 2010
US FDA Update 2010
Braun et al 2011

 Started 2009
 Examining fetal environment, including
BPA exposure
 Following pregnant women and offspring until 21 years of age
 Goal of 100,000 children participants
 Largest, most comprehensive study of its kind in US
Groff 2010
Image: http://www.mrothery.co.uk/images/growth.gif

 Oral ingestion of BPA is metabolized in the intestines and liver to yield metabolite, BPA monoglucuronide, and is excreted in the urine (in humans)
 Acute exposure studies show:
 rapid metabolism of BPA with urinary elimination to be within 24 hours of exposure based on 4-6 hour half-life
Stahlhut 2009
Lang et al 2008
Image: http://image3.examiner.com/images/blog/wysiwyg/image/water_bottle1(1).jpg

 BPA monoglucuronide elimination:
 humans/primates- from the blood via kidneys into urine
 Rodents- bile excretion into feces
 Current safety measured on belief that higher doses result in greater effects
 If higher doses cause no harm, lower doses are deemed safe?
Groff 2010
Lang et al 2008
Taylor et al 2011

 Stahlhut et al suggest a longer than expected half life attributed to either environmental exposure or accumulation in adipose tissue
 Taylor et al compare bioactive BPA
(unconjugated) levels in primates and rodents reporting clearance rates are the same
Stahlhut et al 2009
Taylor et al 2011
Groff 2010
Image: http://maxcdn.fooyoh.com/files/attach/images/3004/141/953/004/Monkey_facepalm.jpg


Over 90% of U.S. individuals have measurable concentrations of BPA in their urine
 Significantly higher levels of BPA in younger children, women, and incomes <
$45,000/year
 1997-2005- 115 studies in US, Japan, and Europe show some effects at or below the reference dose
Braun et al 2011
Lang et al 2008
Groff 2010
Taylor 2011
Vogel 2009
Image: http://3.bp.blogspot.com/_xo0o9nT5MLI/TOq_bZElPYI/AAAAAAAAAB8/nQspiA_mtwY/s1600/MP900431826.JPG

 2007- Chapel Hill Consensus Statement
 BPA, at concentrations found in the human body, is associated with “organizational changes in prostate, breast, testes, mammary glands, body size, brain structure and chemistry, and behavior of laboratory animals.”
 2008- The Center for Evaluation of Risks to Human
Reproduction (CERHR) within the NTP released two statements regarding BPA at current exposure:
 “some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children”
 “minimal concern for the effects on the mammary gland and an earlier age for puberty for females in fetuses, infants, and children”
Vogel 2009
US FDA Update 2010
Image: http://www.knowabouthealth.com/wp-content/uploads/2010/07/BPA.jpg

 January 2010- Food and Drug Administration announces it had some concern about BPA
 November 2010- World Health Organization recommend holding off on regulations that limit or ban use of BPA
 Several local and state governments in US have limited or banned use of BPA
 Oregon Senate Bill: http://gov.oregonlive.com/bill/2011/SB695/
 October 2011- American Chemistry Council asks to phase out allowance of BPA in baby products
US EPA 2010
Brown 2010
USA Today 2011

 By March 2009, major baby bottle companies removed BPA from products
 Sunoco requires written confirmation of BPA plastic not sold to children ≤ 3 years
 2010- General Mills announced next tomato harvest, all Muir Glen tomatoes canned BPAfree

Vogel 2009
Szabo 2008
Eden Foods beans have been BPA free since
1999
USA Today 2011
Image: http://www.kidsbabydesign.com/wp-content/uploads/2009/06/bpa-free-baby-bottles.jpg
Image: http://www.greenbiz.com/sites/default/files/imagecache/wide_large/0410Muir.jpg

 Rudel et al conducted a study following participants measuring BPA at baseline and 3 days post intervention
(eliminating canned/packaged foods)
 50-70% decrease in urinary BPA
Rudel et al 2011
Image: http://3.bp.blogspot.com/_4J97xRX7uok/TG4Bj2OHSII/AAAAAAAAAAk/DOb-TqhLJh0/s1600/Fresh+foods+vs+Canned+foods.png

 Counsel public to:
 Avoid canned foods
 Replace recycling #s 3, 6, & 7 with other recycling #s (1, 2, 4, or 5), stainless steel, or glassware
 Switch from liquid formula to powdered
 Avoid heating BPA plastic
 Replace canned foods with fresh or frozen foods
 Discard scratched baby bottles/cups

Braun 2011
Only use dishwasher safe and microwave safe plastics in appliances
Groff 2010
Bourguignon 2010
US DHHS

 BPA found in plastics (code # 7) and canned foods/beverages
 Health implications include endocrine system disruption, risk of CVD, neurological impairments, obesity, DM2, and liver enzyme abnormalities
 No federal limits or bans on uses
 Dietitian can reduce public exposure by suggesting replacements

Image: http://www.sneakerfiles.com/wp-content/uploads/2011/09/Discussion-The-Discussion.jpg