Harvard Canned-Soup-BPA Study Called “POS” by JunkScience.com
And probably rightly so, given a number of issues.
- The Harvard press release is terribly (and irresponsibly) overdramatic, emphasizing the “endocrine-disrupting” effect of bisphenol A (which is only documented in laboratory animals, to my knowledge) and the >1200% increase in urinary BPA after consuming canned soup (Progresso) for 5 days. There is no mention of absolute numbers in the attention-grabbing press release, just the astonishing percentage jump.
- The JAMA report, available here (courtesy of JunkScience.com), is actually published as a letter and not a more stringently peer-reviewed article.
- JunkScience.com takes the letter authors to task for not distinguishing between the urinary measurement of BPA (which is evidently not possible or very difficult) and that of a quickly produced metabolite. BPA is evidently rapidly processed in the body, and its “biologically inactive” metabolite (not BPA per se) was actually measured in urine, says JunkScience.com (the blog further claims that at least some of the authors should have known or do know this fact).
- While the percentage increase of mean urinary BPA values among canned-soup eaters is very impressive, we’re talking about differences in MICROGRAMS PER LITER: 1.1 mcg/L after 5 days of fresh-soup consumption vs 20.8 mcg/L after 5 days of canned-soup consumption, for a difference of 19.7 mcg/L.*
- The urinary spike in BPA (or its metabolite) was probably transient, and the authors themselves acknowledge, “The effect of such intermittent elevations in urinary BPA concentration is unknown.”
So it’s a non-peer-reviewed study highlighting the transient rise of urinary BPA (or really, a biologically inactive BPA metabolite) after eating canned soup, the significance of which is unknown.
* In the updated National Health and Nutrition Examination Survey, levels of BPA were detected in all subjects older than 6 years of age. Geometric means were approximately 2 mcg/L, but levels rose to 20 mcg/L (or thereabouts) in the 95th-percentile groups.
Image of can of Progresso vegetable minestrone soup from progresso.com.
A native East Tennessean, Barbara Martin is a formerly practicing, board-certified neurologist who received her BS (psychology, summa cum laude) and MD from Duke University before completing her postgraduate training (internship, residency, fellowship) at the Hospital of the University of Pennsylvania in Philadelphia. She has worked in academia, private practice, medical publishing, drug market research, and continuing medical education (CME). For the last 3 years, she has worked in a freelance capacity as a medical writer, analyst, and consultant. Follow Dr. Barbara Martin on Google + and Twitter.
