A new study says that regular consumption of canned soup may be associated with an increase in levels of bisphenol A (BPA), which has been associated with a number of harmful health effects.
Bisphenol A is an industrial chemical used to make polycarbonate plastic for water bottles and food containers as well as the protective lining in metal cans.
Previously, Health Canada focused on removing BPA from baby bottles to reduce exposure in newborns and infants. In August, Statistics Canada reported that more than 90 per cent of Canadians aged six to 79 had detectable levels of BPA in their urine.
The health risks of BPA in humans are unclear. Animal studies suggest that once ingested, BPA may imitate estrogen and other hormones, according to the U.S. National Institutes of Health.
The study authors added that the increase may be temporary and more research is needed.
BPA is an endocrine-disrupting chemical used in the lining of metal food and beverage cans, in polycarbonate bottles, and dentistry composites and sealants. It’s been linked with diabetes, obesity and cardiovascular disease in humans and has been shown to interfere with reproductive development in animals.
The Harvard School of Public Health study included 75 volunteers in two groups. One group ate a 12-ounce serving of vegetarian canned soup each day for five days and the other group ate the same amount of fresh vegetarian soup daily for five days. The groups then switched the type of soup they ate for another five days.
Urine samples showed that daily consumption of canned soup was associated with a more than 1,200 percent increase in BPA, compared to eating fresh soup.
The study appears online Nov. 22 and in the Nov. 23 print issue of the Journal of the American Medical Association.
“Previous studies have linked elevated BPA levels with adverse health effects. The next step was to figure out how people are getting exposed to BPA. 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. This study suggests that canned foods may be an even greater concern, especially given their wide use,” lead author Jenny Carwile, a doctoral student in Harvard School of Public Health’s epidemiology department, said in a university news release.
She and her colleagues noted that the elevation in urinary BPA levels may be temporary and said further research is needed to determine how long it lasts.
“The magnitude of the rise in urinary BPA we observed after just one serving of soup was unexpected and may be of concern among individuals who regularly consume foods from cans or drink several canned beverages daily. It may be advisable for manufacturers to consider eliminating BPA from can linings,” senior author Karin Michels, an associate professor in the epidemiology department, said in the news release.
The U.S. National Library of Medicine has more about BPA.