FDA Defends Plastic Linked To Health Risks

The Food and Drug Administration defended Tuesday a controversial compound found in plastic baby bottles and in food packaging. A major study has linked bisphenol A to possible risks of heart disease and diabetes.

Copyright © 2008 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

STEVE INSKEEP, host:

The Food and Drug Administration has taken another step toward allowing continued use of a chemical. It's a chemical found in everything from baby bottles, to food containers, to sunglasses, to compact discs. It's called bisphenol A, or BPA. But a number of scientists say BPA is dangerous, and their side got a boost this week from a new study, as NPR's Allison Aubrey reports.

ALLISON AUBREY: At a public meeting yesterday, the Food and Drug Administration made its case to a panel of scientific advisers. Michelle Twaroski, a staff toxicologist at the FDA, presented a PowerPoint on how her team assessed the risks of BPA using the best available animal studies, and she summed up the agency's thinking.

Dr. MICHELLE TWAROSKI (Staff Toxicologist, Food and Drug Administration): In conclusion, FDA has considered the available data and determined that the margin of safety for bisphenol A exposure in all populations is adequate, and the continued use of bisphenol A in the manufacturer of food contact substance is concluded to be safe.

AUBREY: But during the next two hours of the hearing, the panel heard from members of the public and outside scientists who take issue with this conclusion. Diana Zuckerman heads an advocacy group called the National Research Center for Women and Families. She criticized the FDA for including so few studies in its assessment. She argued that relying on industry-funded animal studies is not a comprehensive approach.

Dr. DIANA ZUCKERMAN (President, National Research Center for Women and Families): Since these food containers are not proven safe, the FDA should not be assuring us that they are safe. It does feel like there's been a rush to judgment by the FDA, and that does none of us any good.

AUBREY: One the studies not included in the FDA review is published this week in the Journal of the American Medical Association. It comes from researchers in Great Britain. They studied about 1,400 adults, the largest human study to date of BPA. And they found that people who had the highest levels of BPA in their urine were more than twice as likely to have developed diabetes and heart disease. This is compared to those who had the lowest levels of BPA in their urine. The study finds an association between these diseases and BPA, but it does not prove a cause and effect. Environmentalist John Peterson Myers wrote an editorial on the study that was also published in the medical journal. He spoke at the hearing yesterday.

Dr. JOHN PETERSON MYERS (Founder, CEO, Chief Scientist, Environmental Health Sciences): It is very clear that the FDA cannot conclude with certainty that BPA is safe. That option is no longer open to you given these new data.

AUBREY: Concerns about BPA have grown in recent years largely on the basis of animal studies. Some have shown that the chemical, even at low doses, can harm fetuses and offspring of mice and rats. Other studies, including some financed by the chemical industry, find no cause for alarm. Steven Hentges heads the Polycarbonate/BPA Global Group of the American Chemistry Council. He says he trusts the FDA's assessment.

Dr. STEVEN HENTGES (Executive Director, Polycarbonate/BPA Global Group, American Chemistry Council): We actually think the FDA draft report is quite comprehensive, it's quite thorough. It included assessments from international bodies who have reviewed the scientific literature comprehensively.

AUBREY: The panel of FDA advisers now has six weeks to review the agency's assessment and weigh in on whether they agree that the continued use of BPA in food containers is safe. Allison Aubrey, NPR News, Washington.

Copyright © 2008 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.

Study Finds Link Between Plastics Chemical, Disease

Water bottles made with the controversial carbonate plastic bisphenol A, or BPA

Water bottles made with the controversial carbonate plastic bisphenol A, or BPA. David McNew/Getty Images hide caption

itoggle caption David McNew/Getty Images

Q&A: How Am I Affected?

Where is BPA found?

The National Toxicology Program says the main source of human exposure to bisphenol A, or BPA, is the tiny amounts that leach from Nalgene-type polycarbonate water bottles and from metal cans — that could include canned vegetables and fruits — lined with an epoxy resin that contains BPA. The chemical is also found in baby bottles, tableware and food storage containers.

Does BPA cause health problems?

Studies about the effects of BPA have been conflicting. Some animal studies have suggested a link between BPA and effects on the brain, behavior and the prostate gland — and raised concerns about the effects of exposure on the developing fetus and young children. But there are no conclusive studies linking BPA to human health problems.

It's also unclear what determines how much leaching occurs. It may depend on the temperature of the liquid or bottle or how the plastic is reused.

What should I avoid?

To minimize exposure to BPA, the National Toxicology Program recommends that people avoid microwaving plastic food containers or washing them in the dishwasher with harsh detergents. Repeated exposure to high temperatures and harsh cleaning agents can deteriorate the plastic and release BPA.

Additionally, some sources, such as NTP, have advised consumers to avoid hard, clear plastic containers with the No. 7 on the bottom. While the chemical industry maintains that plastic bottles contain little BPA and leach trace amounts too low to be harmful to humans, some companies have voluntarily elected to sell BPA-free products. Nalgene sells BPA-free water bottles, and retailers such as Toys R Us and Wal-Mart offer baby bottles and other children's products that are BPA-free.

— Kathleen Masterson

A new study could change the debate over the safety of bisphenol A, a compound found in many plastics.

It suggests that there is an association between higher exposures to BPA and the development of heart disease and diabetes.

The study, appearing in this week's Journal of the American Medical Association, finds that adults with the highest levels of BPA in their urine were more than twice as likely to report having diabetes or heart disease — compared with adults with the lowest levels of the chemical in their urine.

Though it brings up new possible human health risks, the study, which is being discussed today at a meeting of the Food and Drug Administration's science advisory board, offers no conclusive answers. It does not prove a cause and effect between use of plastic food containers and the development of diabetes or heart disease.

"We don't have a lot of evidence in people about the effects of BPA. This is one of the first studies, and it finds something disturbing. It's suggesting there may be harm in adults, which we didn't really believe based on the animal studies," says David Schardt, a staff scientist with the Center for Science in the Public Interest.

The study uses data drawn from the National Health and Nutrition Examination Survey — a survey conducted by the federal government — isolating a group of adults between the ages of 18 and 74 who are representative of the U.S. population at large. The survey asked a series of health-related questions, and participants provided a urine sample. Researchers then tested the urine samples for a range of compounds, including bisphenol A.

"We were interested in diseases of the 50 and older age group and that's originally what we looked at. And then we realized that these associations went into the larger adult populations. And it just turned out that these signals were exceptionally strong and exceptionally robust," says David Melzer, the study's director and professor of epidemiology and public health at Peninsula Medical School in England.

The researchers adjusted for things like weight and smoking, but the association between high BPA urine levels and likelihood of having the diseases held.

"If you could take two individuals with same sex, race, age, ethnicity, body build, cigarette smoking status, and had one individual that [had] low levels of BPA and one individual that had high levels of BPA, the individual with high levels of BPA would be more likely to also report being a diabetic or having cardiovascular disease history," says Ken Portier, a statistician with the American Cancer Society and an expert at interpreting these kinds of snapshot-in-time studies.

Portier says the findings are certainly strong enough to merit follow-up, and the next step might be to look at another group of the survey participants and see if the associations hold up.

Melzer is scheduled to discuss his findings today at a Food and Drug Administration meeting where the agency has issued a draft proposal on bisphenol A.

At this time, the FDA finds the current level of exposure to BPA through food containers safe.

Related NPR Stories

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.