BPA is used in certain packaging materials such as polycarbonates for baby food bottles. It is also used in epoxy resins for internal protective linings for canned food and metal lids.
Over 2.2 million tonnes of the chemical compound are produced annually, according to the study.
Concerns have arisen over BPA since it has been found to migrate in small amounts into foods and beverages stored in the materials and some recent animal studies indicated that high levels of BPA could be carcinogenic.
The UK authors said their findings, which were published in the Journal of the American Medical Association (JAMA), add to the evidence suggesting adverse effects of low-dose BPA in animals.
Their study found that the 25 per cent of people with the highest levels of BPA in their bodies were more than twice as likely to have heart disease and, or diabetes compared to the 25 per cent of the people with the lowest levels.
Call for ‘scientific follow-up’
The researchers are calling for follow-up studies to confirm their findings:
“Given the substantial negative effects on adult health that may be associated with increased BPA concentrations and also given the potential for reducing human exposure, our findings deserve scientific follow-up.”
The authors said the study is based on the ‘first large scale and high quality population representative (BPA) data set to become available.’
"Widespread and continuous exposure to BPA, primarily through food but also through drinking water, dental sealants, dermal exposure and inhalation of household dusts, is evident from the presence of detectable levels of BPA in more than 90 per cent of the US population,” according to the researchers.
The JAMA study comes on the tails of the US National Toxicology Program's (NTP) final report on BPA, released earlier this month. It expresses concerns over the potential for developmental toxicity for foetuses, infants, and children, based primarily on data from animal studies.
An earlier NTP draft report in April of this year, which drew similar conclusions to the final report, triggered a Food and Drug Administration (FDA) probe into BPA and also encouraged retailers such as Wal Mart to consider removing bottles containing the compound from their shelves.
However, the FDA, at a scientific hearing yesterday reaffirmed its view that BPA in food packaging was safe.
“Right now, our tentative conclusion is that it's safe, so we're not recommending any change in habits," said Laura Tarantino, head of the FDA's office of food additive safety.
In a draft risk assessment on BPA, released in August, the FDA concluded that an adequate margin of safety exists for BPA at current levels of exposure from food contact uses.
However, the FDA officials conceded yesterday that further research is needed.
"We recognise the need to resolve the concerning questions that have been raised," said Tarantino.
Food and drink sector
The Food and Drink Federation (FDF) and the British Soft Drinks Association (BSDA), in relation to the JAMA study, said:
“Bisphenol A has been approved as safe for use in food and drink containers by the European Food Safety Authority (EFSA), the UK Food Standards Agency (FSA) and the FDA. Its use is closely monitored and regulated.
“Bottled water bottles and plastic soft drinks containers do not contain BPA. Food and drink can-linings that include BPA contain well below the Tolerable Daily Intake (TDI) level set by EFSA.
“The authors of the study itself confirmed that more research was necessary before any conclusions could be reached.”
Meanwhile, a spokesperson for EFSA told FoodProductionDaily.com that the agency constantly reviews new scientific publications with a view to reviewing its opinions when this is considered to be necessary.
“The latest developments regarding BPA will be discussed at the plenary meeting of the panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids from 22 to 24 September,” said the spokesperson.
In an opinion issued in July, the agency said that the human body rapidly metabolises and eliminates BPA and thus the substance presents no risk to adults, children or infants.
EFSA said that, as a result of the assessment, the Tolerable Daily Intake (TDI) of 0.05 milligram/kg body weight per day it had set following its previous BPA assessment remained valid.
‘No basis for health concerns’
Plastics Europe, which represents the interest of theEuropean plasticsmanufacturing industry, said that the weight of the scientific evidence shows that there is no basis for health concerns over human exposure to BPA.
Jasmin Bird, communications manager for the polycarbonate/BPA section of the trade association, said that the study published in JAMA has significant limitations and is flawed.
“BPA is one of the most widely studied compounds in the world, and existing scientific evidence from many studies does not ‘match’ the associations found in the JAMA work,” argues Bird.
And the North American Metal Packaging Alliance (NAMPA) said the study provides no scientifically defensible answers:
“To suggest that BPA concentrations measured at a single point in time during the process of elimination from the body correlate in any way directly with serious chronic disorders is entirely unsupported and an unsubstantiated scientific leap,” claims NAMPA.
Source: Journal of the American Medical Association (JAMA) Vol. 300 No. 11, September 17, 2008Published online ahead of print (doi:10.1001/jama.300.11.1303)Association of Urinary Bisphenol A Concentration with Medical Disorders and Laboratory Abnormalities in Adults Authors: I. A. Lang; T. S. Galloway; A. Scarlett; W. E. Henley; M. Depledge; R. B. Wallace; D. Melzer