Research says chemical in plastics and cans may contribute to obesity
By David Knowles,
A controversial chemical used to harden plastics is contributing to the global obesity epidemic, according to new research by a biologist.
The claims by leading BPA critic Frederick vom Saal come as the Food and Drug Administration is expected to rule this week — after four years of study — on whether to ban the plastic additive from use in food packaging.
Vom Saal told The Daily he will soon release a new study showing that mothers who expose their fetuses to the bisphenol A run the risk of having obese children.
“During the development of the fetus, BPA exposure alters the development of stem cells,” said vom Saal, a professor at the University of Missouri. “Think of it as tripping a switch in the DNA. BPA turns out to be a major factor in the number of fat cells that a person will have later in life.”
BPA first came to public consciousness in 2007 when concerns were raised that it was leaching from reusable water bottles, leading to most companies reformulating their containers. But the organic compound is still so ubiquitous that it has been found in the urine of 93 percent of Americans over age 6. It’s used to line metal food and beverage cans, and is found in dental sealants, household appliances and sports equipment.
Critics label BPA an “endocrine disruptor” that acts like synthetic estrogen and link it to a wide range of ailments, including cancer and neurological problems. But its scientific defenders — as well as regulatory agencies in the United States, Australia, the European Union, Japan, and New Zealand — say there’s no evidence that the minuscule exposure that consumers receive poses a health risk. Teasing out the truth has been difficult because it’s unethical to experiment on humans.
Vom Saal, who has researched BPA for two decades, said that his study shows that even trace amounts of the chemical — well below those found to leach from cans into soup or soda — are enough to disrupt a developing child’s genetic structure and lead to metabolic disorders.
“BPA changes genes permanently,” vom Saal said. “It’s forever. You can’t turn nerve cells into muscle cells when you’re an adult.”
Thousands of studies on BPA over the past few decades have yielded conflicting results. In September 2010, the European Food Safety Authority analyzed 800 such studies and concluded that BPA did not pose a public health risk at low doses.
“BPA is one of the most thoroughly tested chemicals in commerce today,” the American Chemistry Council, an industry group fighting the move to ban BPA from food containers, said in a news release. “The consensus of government agencies across the world is that BPA is safe for use in food-contact materials intended for infants and toddlers.”
But over the past few months, a slew of new research has focused on the BPA-obesity link. Vom Saal’s findings are just the latest new evidence that BPA may be playing a role in the global obesity epidemic. Another study released in February by a Spanish research team showed that even small amounts of BPA cause human adult islet cells to produce more fat in the body.
“Our research indicates that human pancreatic beta cells, which synthesize and secrete insulin, are over-secreting insulin if BPA is present,” Angel Nadal, professor of physiology at Spain’s University Miguel Hernandez and the lead author of the paper published in PLoS ONE, told The Daily. “Certainly it is likely that a part of these metabolic pathologies are caused by BPA. What percentage of it is due to BPA and other pollutants? We still don’t know.”
Both studies identify a method in which BPA could cause obesity, unlike other past studies that have merely noted a correlation.
A report last week by British activist group Chem Trust, which reviewed all existing studies linking chemicals like BPA with obesity and diabetes, concluded that the compounds posed a serious health risk.
“The epidemics in obesity and diabetes are extremely worrying,” Spanish researcher Miquel Porta, the lead author of the survey, said in a news release. “The role of hormone disrupting chemicals in this must be addressed.”
“The evidence is growing, and the new studies are passing a certain bar in terms of credibility,” Sheldon Krimsky, a professor at Tufts University and the author of the book “Hormonal Chaos,” told The Daily. “The idea that there may be a chemical factor that accounts for obesity is a real game-changer. In the past, we’ve always gone towards fast food and lack of exercise, but now we’re forced to consider that another reason might be BPA.”
After long declaring that BPA was safe in low doses, the FDA amended its position on the chemical in 2010, stating that ongoing research showed that there was cause for “some concern” for its effects on fetuses, infants and children. In response to a court order, the FDA is now reviewing whether BPA should be removed from food containers, and has agreed to make a decision by Saturday.
“If we determine it isn’t safe to use it anymore, we have to change those regulations,” FDA spokesman Douglas Karas said. “That doesn’t happen overnight.”
For Krimsky, vom Saal and Nadal, there’s already more than enough evidence for the FDA to act.
“It takes 90 days under the Toxic Substances Control Act to get a chemical approved for sale on the market,” Krimsky said. “Getting a product off the market that has been shown to be unsafe, on the other hand, takes somewhere between 25 and 50 years, because industry says we need definitive science.”
Initially created to make plastics stronger, BPA was introduced an as epoxy resin to add shelf life to canned goods in the late 1950s. Though known to be toxic, the chemical was one of 62,000 that Congress grandfathered in as safe under the Toxic Substances Control Act of 1976.
The act gives the Environmental Protection Agency the power to regulate toxic chemicals, but that agency doesn’t appear poised to do so with BPA.
“Human exposure appears to occur primarily through food packaging manufactured using BPA, although those products account for less than 5 percent of the BPA used in this country,” the EPA told The Daily in a statement. “Since food packaging is under the jurisdiction of the Food and Drug Administration … EPA does not intend to initiate regulatory action under [the Toxic Substances Control Act] at this time on the basis of risks to human health.”
The American Chemistry Counsel, which represents BPA manufacturers like Dow Chemical, recently called on the FDA to revise current regulations so that synthetic estrogen will be banned from use in plastic baby bottles and sippy cups, bringing U.S. standards in line with those in Canada and Europe. Meanwhile, companies like Campbell’s Soup Co. and H.J. Heinz Co. are taking steps to rid their packaging of BPA.
“We have already started using alternatives to BPA in some of our soup packaging, and we are working to phase out the use of BPA in the lining of all of our canned products,” Campbell’s Vice President Craig Owens told shareholders recently.
Yet, as governments around the world continue to tinker with the idea of enacting new BPA regulations, obesity rates continue to rise.
Half of the developed world is now considered overweight, according to the Centers for Disease Control and Prevention. While the rise of obesity has been a complex and multifaceted phenomenon, vom Saal says that a growing body of research shows that BPA is a contributing factor.
“In 1970, 50 million pounds of BPA were manufactured. Now there are 10 billion pounds per year. It has become a $10 billion-a-year chemical,” vom Saal said.
(Source: www.thedaily.com )