The Chronicle

Issue date: 11/18/08 Section: News
Last update: 11/18/08 at 5:37 AM EST

Media Credit: Margaret Baughman

Students may want to think twice before they grab a can of Busch Light at a section party or chug a bottled water after a long workout.

A recent study at Duke has added to evidence that suggests a chemical in these common beverage containers could be health hazards.

Randy Jirtle, lead researcher in the study and associate professor in the department of radiation oncology, said he found that the chemical Bisphenol A produces negative effects in mice. The chemical, known as BPA, mimics estrogen and links together to form clear, hard plastic-so it is often found in shatterproof plastic water bottles and in the linings of aluminum cans, sodas and beers, Jirtle said.

Exposure to harsh conditions, such as acid, high heat or alcohol causes the BPA to leach into the water, he added.

Only recently have the potentially harmful effects of BPA come under scientific scrutiny. Jirtle is one of several researchers who have found the chemical can alter the human epigenome to increase risk of diabetes, obesity and cancer.

The epigenome dictates what our genome should do, much like a computer's hardware, Jirtle explained.

"Think of your epigenome as the software that tells your body what to do," Jirtle said. "[By consuming BPA] in effect you have a program with bugs, even if the hardware is perfectly fine."

In his study, Jirtle said he fed pregnant mice doses of BPA similar to the amounts the average person consumes daily. The BPA changed not only the offspring's coat­-from brown to yellow-but also made them more obese and consequently more likely to contract diabetes or cancer, Jirtle said.

Jirtle suggests that people who plan to get pregnant or are in late adulthood should especially avoid BPA because the epigenome is more sensitive in fetuses and the elderly.

"A very small amount has the potential of a very subtle impact on your bodily functions," said Bill Chameides, dean of the Nicholas School of the Environment.

In order to minimize consumption of BPA, Chameides said he suggests avoiding No. 7 plastic bottles, like 5 gallon water bottles, and limiting usage of No. 3 plastics, like juice bottles and cling wrap and No. 6 plastics found in disposable cups and cutlery.

He also recommends not drinking from plastic water bottles or canned foods that have been heated-in a car or a microwave, and not consuming any canned alcoholic beverages.

"If you have the option of buying glass instead of plastic, buy glass," he added.

Although Dr. Dennis Darcey, assistant professor of occupational and environmental medicine, is not an expert on BPA, he said that it is easy to find alternative materials without BPA.

"It is up to individuals to avoid using BPA products," he said.

Jirtle also mentioned that supplementing your diet with vitamin B-12 and folic acid counters the effects of BPA but should not be considered a solution to the problem.

Darcey added, however, that more research needs to be done before scientists are sure about long-term effects.

It is difficult to extrapolate the BPA phenomenon from mice to humans, Jirtle added.

The bottom line, Chameides said, is not to panic but to try to avoid BPA whenever possible.

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