PEOPLE who ate canned soup for five days straight saw their urinary levels of the chemical bisphenol A (BPA) spike 1200 % compared to those who ate fresh soup, US researchers found.
“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 litre 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, the lead author said. BPA is found in the lining of canned foods, cash register receipts, dental fillings, some plastics and some polycarbonate bottles.
Seventy-five people took part in the study, eating a 12 ounce (340 g) serving of either fresh or canned soup for five days in a row and were told not to otherwise alter their regular eating habits.
A urine analysis showed the canned soup eaters had 1221% higher levels of BPA than those who ate the fresh soup.
BPA is typically eliminated in the urine so more studies were needed to examine how long elevated levels may remain in the body, the researchers said. JAMA 2011:306:2218-20