Agence France Presse | Common Dreams
November 23 2011
WASHINGTON – People who ate canned soup for five days straight saw their urinary levels of the chemical bisphenol A spike 1,200 per cent compared to those who ate fresh soup, U.S. researchers said on Tuesday.
The randomized study, described as “one of the first to quantify BPA levels in humans after ingestion of canned foods,” was done by Harvard University researchers and appears in the Journal of the American Medical Association’s November 23 issue.
“We’ve known for a while that drinking beverages that have been stored in certain hard plastics can increase the amount of BPA in your body,” said lead author Jenny Carwile, a doctoral student in the Department of Epidemiology at Harvard School of Public Health.
“This study suggests that canned foods may be an even greater concern, especially given their wide use.”
The chemical BPA is an endocrine disruptor that has been shown to interfere with reproductive development in animal studies at levels of 50 micrograms per kilogram of body weight and higher, though it remains uncertain if the same effects cross over to humans, according to the Environmental Protection Agency.
This study did not measure BPA levels by micrograms per kilogram of body weight, but rather by micrograms per liter of urine, so a direct comparison to the EPA-cited danger level in animals was not possible.
However, previous studies have linked BPA at lower levels than those found in the Harvard study to cardiovascular disease, diabetes and obesity in humans, Carwile told AFP in an email.
BPA is found in the lining of canned foods, cash register receipts, dental fillings, some plastics and polycarbonate bottles marked with the number 7.
Seventy-five people took part in the study, eating a 12-ounce serving of either fresh or canned soup for five days in a row. They were advised not to otherwise alter their regular eating habits.
After a two-day break, the groups switched and ate the opposite type of canned soup.
A urine analysis showed the canned soup eaters had 1,221 per cent higher levels of BPA than those who ate the fresh soup.