(CNN)There has been an ongoing debate about just how much of the industrial chemical Bisphenol A (or BPA) lurks in canned foods and whether it poses a health risk.
For more than 40 years, BPA has been widely used in consumer products, such as the inside lining of cans, to prevent metal corrosion and breakages, preserving the food inside.
Now, a study published in the journal Environmental Research on Wednesday not only reveals that consuming canned foods can expose our bodies to BPA, it pinpoints the worst offenders.
The study suggests that canned soups and pasta can expose consumers to higher concentrations of BPA than canned vegetables and fruit — and although those foods are tied to BPA concentrations, canned beverages, meat and fish are not.
“This knowledge can help guide consumers when making decisions as to which canned products they choose to buy,” said Deborah Kurrasch, an assistant professor at the University of Calgary Cumming School of Medicine who was not involved in the study.
“I am not surprised by these research findings, as others have shown that consuming canned foods is one of the highest routes of exposure to BPA,” she said. “This study serves to illustrate that consuming canned foods continues to be a source of contamination.”
The study included data collected on 7,669 people, ages 6 and older, in the United States between 2003 and 2008 as part of the National Health and Nutrition Examination Survey.
The researchers analyzed the data, which indicated what each person had eaten in the past 24 hours as well as whether BPA concentrations were detected in each person’s urine on the same day.
“Urinary BPA concentrations are evidence of BPA exposure,” said Jennifer Hartle, postdoctoral research fellow at Stanford University School of Medicine and lead author of the study.
The researchers found that people who consumed one canned food item in the past day had about 24% higher concentrations of BPA in their urine compared with those who had not consumed canned food. The consumption of two or more canned food items resulted in about 54% higher concentrations of BPA.
“We could see a clear association with canned foods,” Hartle said.
Cream of mushroom vs. canned peaches
Once the researchers evaluated what types of canned foods were consumed, they found that eating canned soup resulted in a whopping 229% higher concentration of BPA compared with consuming no canned foods. Canned pasta resulted in 70% higher concentrations, and canned vegetables or fruit resulted in 41% higher concentrations.
Someone who eats a single can of cream of mushroom soup may still have a greater exposure to BPA than someone who eats three cans of peaches, Hartle explained.
But why exactly might canned soup result in higher BPA concentrations than other foods? Hartle said it might have something to do with how much heating soup requires when it is processed, and it tends to have a higher amount of fat.
“A canned soup — which oftentimes is solid and a liquid — usually needs a long heating time to get all of the contents to the same temperature needed to sterilize the food. Many canned beverages (beer, soda, juice) are acidic, so their thermal processing requirement is much different,” she said. “Another factor is that BPA partitions to, or moves into, solids. … Other key factors are the chemical composition of the lining and the fat content of the canned food, as BPA is lipophilic.”
Scientists have continued to examine whether BPA exposure from canned foods poses a health risk. The concern stems from how BPA can hack and disrupt the normal responses of hormones in the body. For instance, it can mimic the effects of estrogen. In doing so, it can reprogram cells, causing a plethora of health problems.
“BPA exposure is associated with many adverse health effects including diabetes, obesity, cardiovascular disease, reproductive development issues, amongst others,” Hartle said.