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Recent JAMA Study Findings Raise New Concerns
about
the Safety of Bisphenol A (BPA)
You may have heard about the potential harmful effects of BPA,
a chemical modifier commonly used in some plastic containers
and the linings of some canned foods. Now, a new study
published in the Sept. 17, 2008, issue of the Journal of the
American Medical Association (JAMA) highlights BPA's potential
health risks, reaffirming the importance of Shaklee's
commitment to BPA-free packaging as a part of our longtime
emphasis on consumer safety.
British researchers Lang and colleagues report the results of
the first major epidemiologic study to examine the health
effects associated with BPA and show that higher urine BPA
levels are correlated with higher prevalence of cardiovascular
disease (coronary heart disease, heart attack, and angina),
diabetes, and liver enzyme abnormalities. The cross-sectional
study of 1,455 adults, intended to be representative of the
adult U.S. population, found double the normal risk for heart
disease and diabetes, but also discovered no association with
any other health effects. The investigators also indicate that
these findings add to the evidence suggesting adverse effects
of low-dose BPA on animals but emphasize that independent
replication and follow-up studies are needed to confirm both
the findings and whether the associations are causa l.1
An accompanying editorial also suggests that U.S. regulatory
agencies should follow recent Canadian government decisions
and require aggressive action to reduce human and environmetal
exposures to BPA.2,3
In 2007, the Centers for Disease Control and Prevention (CDC)
published results that BPA had been detected in the urine of
nearly 93% of those tested, a finding indicating widespread
exposure to BPA in the U.S. population. This analysis looked
at urine samples obtained from 2,517 people ages 6 and older
who took part in CDC's National Health and Nutrition
Examination Survey (NHANES) between 2003 and 2004. Females had
higher levels than males, and children had the highest levels,
followed by teens and adults.4
Shaklee's Commitment to BPA-Free Packaging
Shaklee's first commitment is to product safety and, as such,
our product packaging has long been free of plastics that
might contain the potential toxin bisphenol A. Today, you can
rest assured that all Shaklee products are packaged in BPA-free
materials.
Common
Exposures from BPA
BPA is a chemical produced in large quantities primarily for
use in the manufacture of polycarbonate plastics and epoxy
resins. Polycarbonate plastics typically are clear and hard
and have many applications, including use in certain food and
beverage packaging such as water and infant bottles, as well
as compact discs, impact-resistant safety equipment, and
medical devices.
According to the CDC, about 7 billion pounds of BPA are
produced worldwide each year, and the Centers' analyses have
found that 93% of Americans have detectable levels in their
urine.4,5,6 Animal studies have linked high levels
of BPA to increased risk for diabetes, brain damage,
developmental abnormalities, certain precancerous changes, and
a variety of other health problems.7, 8, 9 The
cause of the increased risk has not been fully determined, but
various theories include BPA's potential action as a hormone
disruptor or modulator.4, 9
Two studies conducted earlier this year provided possible
explanations of the recent findings published in JAMA. In
April, Spanish researchers reported that BPA caused pancreatic
cells to increase their production of insulin in mice, leading
to insulin resistance, a precursor of diabetes.10 A
separate study at the University of Cincinnati showed BPA
inhibits the release of a key biochemical that protects humans
from metabolic syndrome, a collection of health risks that
increase a person's chances of developing heart disease,
stroke, and diabetes.11
Government Positions on BPA Safety
The FDA has long argued that there is an existing margin of
safety that is adequate to protect consumers--including
infants and children--at the current levels of exposure.
However, others point out that the FDA's conclusions are based
on selected studies and don't adequately consider studies that
found adverse effects.9 Earlier this year, the
National Toxicology Program explained in a preliminary report
there was some concern that the chemical posed a risk to
fetuses, babies, and children, as emphasized in this latest
JAMA study.12 Specifically, researchers and public
health activists also are calling upon the U.S. government to
consider alignment to a recent action by the Canadian National
Public Health Agency, which in May 2008 released a report
calling BPA a potentially harmful chemical.
Reducing
Exposure to Harmful BPA
Although there are no official recommendations for reduced
exposure levels set by leading public health organizations,
there are important steps consumers can take to minimize BPA
exposure. The following are a number of simple suggestions to
help you reduce your BPA exposure and are based on
recommendations from the Environmental Working Group (EWG).13,
14
Basic
Tips to Reduce Exposure to and Intake of BPA
· Avoid Reusable Polycarbonate (labeled #7) Plastic Water and
Baby Bottles. As a general rule, avoid water bottles and baby
bottles labeled #7, which tend to be hard and clear. Many
reusable water bottles are made of polycarbonate
plastic--including many of the popular colorful plastic water
bottles--that leaches BPA into the water. Choose polyethylene
or unlined aluminum bottles instead. Use glass baby bottles
instead of plastic, and always discard damaged plastic
containers. These are better choices for you, your family, and
the planet.
· Avoid Polycarbonate Plastic Food Containers and Tableware.
These may also be labeled "PC" underneath a plastic code #7 in
the recycling triangle on the bottom of the container.
Representing a better choice are usually the BPA-free plastics
with the recycling labels #1, #2, or #4 and #5. Be aware that
BPA can leach from the plastic into foods and beverages,
especially when the material is heated or used for long
periods of time. Opt for ceramic, glass, or other microwavable
dishware. Soft or cloudy-colored plastic containers do not
contain BPA.
· Minimize the Use of Canned Foods and Canned Drinks. Until
industry reformulates the lacquer lining of metal cans, limit
your consumption of certain canned foods such as tomato sauces
because the high acidity causes more of the chemical to leach
from the lining of the can. Choose fresh or frozen foods or
those in glass containers or bottles. The recent study by EWG
found BPA in more than half of the 97 cans of brand-name
fruit, vegetables, soda, and other common canned goods that
were tested.
· Ask your Dentist for BPA-Free Sealants and Composite
Fillings. Some dental resins are free of, or low in BPA. Ask
your dentist if he or she knows about BPA and ask him or her
to use low- or no-BPA dental compounds.
· Avoid microwaving or heating any food in plastic containers
or canned food. Heating any plastic materials may release
plastic modifiers directly into food.
Be well!
Dr. Jamie McManus, M.D., FAAFP
Chairman,
Medical Affairs, Health Sciences & Education
References:
1. Lang IA et al., Association of Urinary Bisphenol a
Concentration with Medical Disorders and Laboratory
Abnormalities in Adults, JAMA. 2008; 300(11):1303-1310. 2. Vom
Saal FS et al. Bisphenol A and Risk of Metabolic Disorders.
JAMA. 2008; 300(11): 1353-1355. Published online Sept. 16,
2008 (doi:10.1001/jama.300.11.1353). 3. Environment Canada.
Draft Screening Assessment for The Challenge: Phenol, 4,
4'-(1-methylethylidene) bis-(Bisphenol A). Chemical Abstracts
Service Registry No. 80-05-7. Environment Canada Web site at
http://www.ec.gc.ca/substances/ese/eng/challenge/batch2/batch2_80-05-7.cfm.
20084. 4. Centers for Disease Control and Prevention (CDC).
National Health and Nutrition Examination Survey Data 2003-04.
Hyattsville, MD: U.S. Dept. of Health and Human Servi ces,
CDC; 2007 and special CDC Fact Sheet, May 2008. 5. Centers for
Disease Control and Prevention (CDC). Third National Report on
Human Exposure to Environmental Chemicals. Atlanta, GA: CDC;
2005. 6. Calafat AM et al. Exposure of the U.S. population to
bisphenol A and 4-tertiary-octylphenol: 2003-04. Environ
Health Perspect. 2008; 116(1):39-44. 7. Richter CA, et al. In
vivo effects of bisphenol A in laboratory rodent studies.
Reprod Toxicol. 2007; 24(2):199-224. 8. Wetherill YB et al. In
vitro molecular mechanisms of bisphenol A action. Reprod
Toxicol. 2007; 24(2):178-198. 9. Environmental California.
Bisphenol A Overview. At
www.environmentalcalifornia.org., accessed 9/08. 10.
Ropero AB et al, Bisphenol-A disruption of the endocrine
pancreas and blood glucose homeostasis. Int J Androl. 2008
Apr; 31(2):194-200. Epub 2007 Oct 31. 11. Eric R. Hugo et al,
Bisphenol A at Environmentally Relevant Doses Inhibits
Adiponectin Re leasefrom Human Adipose Tissue Explants and
Adipocytes. Environ Health Perspect doi:10.1289/ehp.
11537 available via
http://dx.doi.org/ [Online 14 August 2008]. 12. National
Toxicology Program (NTP). Draft NTP brief on bisphenol A. NTP
Web site.
http://cerhr.niehs.nih.gov/chemicals/bisphenol/BPADraftBriefVF_04_14_08.pdf.
April 14, 2008. Accessed July 5, 2008. 13. Oregon
Environmental Council at
http://www.oeconline.org/our-work/kidshealth/pollutioninpeople/solutions/bpa.
14. Environmental Working Group (EWG).Review more specifics at
website of the Washington, D.C.-based Environmetal Working
Group at
http://www.ewg.org/reports/bisphenola , A Survey of
Bisphenol A in US Canned Foods, March 2007. |
