Published in Primary Care
Expert Opinion / Commentary · February 25, 2015
Written by Jamie Harvie PE
Written by Nancy Sudak MD
Bisphenol A (BPA) is a chemical widely used in plastic bottles, the lining of canned foods, paper receipts, dental amalgams, and other products. Exposure is ubiquitous, and BPA is most well-known for its estrogenic qualities, although it is also linked to cancer, diabetes, obesity, and heart disease, as well as developmental problems in infants and children. In a study published recently in Hypertension, researchers were interested in elucidating the effects of BPA on blood pressure and heart rate variability.1 As numerous studies have shown that BPA in the epoxy coating of cans leaches into food, the researchers designed a randomized crossover trial in a small population of elderly people in Seoul to examine whether consuming canned beverages elevated blood pressure or diminished heart rate variability.
A total of 60 participants were provided the same beverage in two glass bottles, two cans, or one of each, over three visits. Urinary BPA concentration, blood pressure, and heart rate variability were measured 2 hours after the consumption of these beverages. Urinary BPA concentration increased by >1600% after consumption from cans vs glass containers. Systolic blood pressure adjusted for daily variance increased by a statistically significant 4.5 mmHg after consumption of two canned beverages as compared with glass beverages. It was acknowledged that, although blood pressure was the lowest after consuming the beverage in glass bottles and highest after consuming beverages from the cans, the differences did not achieve statistical significance. Heart rate variability did not show any statistical differences. Researchers concluded that consuming canned beverages increases BPA exposure and increases blood pressure acutely.
While this study suggested the potential for chronic elevation of blood pressure from BPA exposure, further study is needed as little is understood about the physiologic mechanism of increased blood pressure after BPA exposure. Some of the shortcomings acknowledged in the study included the use of spot urine samples rather than longer-term collection, the fact that most of the participants were women over 60 years (limiting the generalizability of the results), and the theoretical possibility that additional chemicals ingested in the beverage could confound the results. Nevertheless, the study adds to the growing body of evidence between environmental exposure to BPA and a variety of other human health impacts.
Although outside the scope of this study, it should be noted that CDC biomonitoring demonstrates the ubiquity of human exposure to a multitude of environmental toxicants. Of the approximately 80,000 chemicals in commerce, the majority of have little or no health and safety testing, or any evaluation of synergistic effects. As a result, clinical approaches include but are not limited to teaching consumers what to avoid, targeted detoxification and nutritional supplementation, and the support of chemical policy reform initiatives.