Can of Soup a Day Linked to High BPA Levels in Urine

Nov. 22, 2011 -- Eating just one 12-ounce serving of canned soup a day for five days straight may lead to more than a 1,000% increase in the amount of the controversial chemical bisphenol A (BPA) in your urine, a new study shows.

BPA is a chemical used in the manufacturing of many metal food and beverage cans, among other uses.

The canned soup study did not look at how -- or even if -- the BPA spike in urine affects health. This is a major sticking point for many critics of the study who caution against overinterpreting the findings.

Previous research has linked BPA to a risk of breast and prostate cancer in animals and obesity, thyroid problems, reproductive abnormalities, heart disease, and neurologic disorders in humans.

Because of health concerns, many companies have taken steps to eliminate BPA from baby bottles and sippy cups, and others are looking into alternatives to BPA for their products.

As part of the new study, 75 volunteers ate either a 12-ounce serving of vegetarian canned soup every day for five days or a 12-ounce serving of non-canned, fresh vegetarian soup for five straight days.

After a two-day wash-out period, participants switched groups. "After just five days of canned food consumption, there was more than a 1,000% increase of BPA in urine," says study researcher Jenny L. Carwile. She is a doctoral student in epidemiology at the Harvard School of Public Health in Boston.

The study is published in TheJournal of the American Medical Association.

The findings likely represent a temporary peak in BPA levels. Researchers do not know how long this peak lasts or what type of effects it may have on health.

Although the canned soup used in the study was a single brand, Progresso, "it is not about the brand of soup or canned soup, it is about the cans," Carwile says. She says the findings likely apply to other canned foods that use BPA in the liner.