June 13, 2013
Bisphenol-A Linked To Obesity In Pre-Teenage Girls
Lawrence LeBlond for redOrbit.com - Your Universe Online
In a new study by researchers with Kaiser Permanente, it has been found that girls between nine and 12 years of age with above average levels of BPA in their urine had twice the risk of being obese than girls with lower levels of the chemical. The study is published today in the journal PLoS ONE.
Lead author De-Kun Li, MD, PhD, a reproductive and perinatal epidemiologist at KP Division of Research in Oakland, Cailfornia, said 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.”
BPA is known as an endocrine disruptor with estrogenic properties. In children, BPA is likely to enter the body through ingestion of foods and liquids that have come into contact with materials containing BPA, said Dr. Li.
“Girls in the midst of puberty may be more sensitive to the impacts of BPA on their energy balance and fat metabolism,” Dr. Li noted, adding that BPA has been shown to interfere with the body´s process of relating fat content and distribution.
Dr. Li said this study is the first that was specifically designed to examine the link between BPA and obesity in school-age children. The study was conducted in Shanghai as part of a larger national study of puberty and adolescent health.
For the study, Dr. Li and colleagues enlisted 1,326 children in grades four through 12 at three schools in the Shanghai area. The study team collected urine samples using BPA-free materials and obtained information on risk factors for childhood obesity such as diet, physical activity, mental health and family history.
The research team found that for girls between the ages of nine and 12, those with BPA levels of 2 micrograms per liter in their urine had double the risk of having a body weight in the top 10th percentile for girls of their age in the same population. For girls in the same age group with BPA levels of 10 micrograms per liter, the risk of obesity was five times greater.
The team did not find significant effects from BPA in any other groups studied, including girls over 12 years of age and boys of all ages. For the nine-to-12-year-old group of girls, 36 percent with a higher-than-average level of BPA in their urine were overweight or obese compared to 21 percent of those with lower-than-average BPA levels.
“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 said. “Worldwide exposure to BPA in the human population may be contributing to the worldwide obesity epidemic.”
This was not the first study that Dr. Li and his colleagues conducted pertaining to BPA exposure in humans.
In a 2013 study, the research team looked at the role BPA played in fertility and sterility in male subjects. They discovered that those exposed to BPA in a chemical plant for six months or longer had lower testosterone in their blood than those who were not exposed to the chemical.
The team also conducted several studies in 2011, showing the link between BPA and birth defects, pregnancy and sperm motility. Other research has included BPA risk on sexual dysfunction in men.
KP is committed to researching the effects of BPA and looking for safer alternatives to products that may contain BPA and other potentially harmful chemicals. The group´s Sustainability Scorecard for Medical Products requires suppliers and manufacturers to disclose the presence of BPA in all products. KP was also instrumental in the removal of BPA from packaging of supplemental nutrition and infant formula products.
The latest study was funded in part by the National Natural Science Foundation of China (NSFC).