Bisphenol-A, known as BPA, is an industrial chemical used to make certain kinds of plastics and resins. It is commonly used to line canned foods, water bottles, baby bottles, and baby formula cans. BPA is a known endocrine disruptor with estrogenic properties. A new study links obesity risk in young girls (ages nine to 12) with higher-than-average levels of BPA in their urine.
The study by Kaiser Permanente looked at 1,326 male and female children in grades 4 through 12 at three Shanghai schools. The researchers collected urine samples, plus obtained information on obesity risk factors, including dietary patterns and physical activity. What they found is that girls ages 9 to 12 years old who had higher-than-average levels of BPA in their urine (two micrograms per liter or more) had twice the risk of weighing in the top 10th percentile for girls of their age in the same population.
Girls with extremely high levels of BPA (more than 10 micrograms per liter) had a risk of being overweight (in the top 10th percentile) five times greater than girls with lower BPA levels. Among the nine to 12 year old girls studied, 36 percent of them with higher-than-average levels of BPA in their urine were overweight or obese, compared with 21 percent of those with lower-than-average levels of BPA.
- The study is the latest in a series of studies by the same researchers, including:
- A study published earlier this year found that male workers exposed to BPA in a chemical plant for six months or more had lower testosterone levels in their blood than those not exposed to BPA
- A 2011 study found a mother’s exposure to BPA while pregnant was associated with a lower birth weight in her baby
- A 2010 study found that increasing BPA levels in urine were associated with decreased sperm concentration, decreased total sperm count, decreased sperm vitality and decreased sperm motility
“This study provides evidence from a human population that confirms the findings from animal studies — that high BPA exposure levels could increase the risk of overweight or obesity,” said De-Kun Li, MD, PhD, MPH, principal investigator of the study and a reproductive and perinatal epidemiologist at the Kaiser Permanente Division of Research in Oakland, Calif.
“Girls in the midst of puberty may be more sensitive to the impacts of BPA on their energy balance and fat metabolism,” Dr. Li said.
“Our study suggests that BPA could be a potential new environmental obesogen, a chemical compound that can disrupt the normal development and balance of lipid metabolism, which can lead to obesity,” Dr. Li and co-authors wrote in PLOS ONE. “Worldwide exposure to BPA in the human population may be contributing to the worldwide obesity epidemic.”
How to avoid BPA exposure
The best way to avoid BPA exposure is to eliminate common sources of BPA, including plastic bottles and canned goods. If you do need to buy canned foods, do so from companies that do not line cans with BPA. Here is a list of companies committed to packaging their products in BPA-free cans:
Eden Foods-sells the widest range of BPA-free canned foods, including beans, vegetables, tomatoes and tomato sauce
Oregon’s Choice-canned tuna
Vital Choice-canned seafood, including tuna
Wild Planet Foods-canned tuna and sardines
Edwards & Sons brands, Native Sons and Native Forest-canned artichoke hearts, asparagus, mushrooms, pineapples, pears, peaches, and coconut milk cans
Farmer’s Market-canned pumpkin, pumpkin pie mix, sweet potato puree, and butternut squash
Muir Glen-canned tomatoes, tomato sauce and tomato paste
Bionaturae’s organic canned tomatoes-an Italian company that also sells other products, including pastas
Photo Credit: zone41