Why are canned food considered unhealthy?

Canned soup with side effects

The main sources of BPA in everyday life are polycarbonate containers and epoxy resins, which are used, for example, to coat metal containers such as food cans. The latter was now the focus of the US team, which consisted of doctors from the renowned Harvard University and the no less well-known CDC. The idea: The researchers wanted to test whether regular consumption of canned food, in this case various vegetable soups, already had a measurable effect on the amount of BPA in the body.

So they recruited a total of 75 volunteers and divided them into two groups. One was given a bowl of canned vegetable soup every day and the other a comparable but freshly prepared soup? without the test persons knowing which group they belonged to. After five days of running time and a further two days' break, the groups were then swapped, so that the other test participants now received the fresh and long-life soup for five days.

Surprisingly clear result

The effect was surprising even for the researchers: during the phase with the fresh soup, BPA was found in the urine of only 77 percent of the test subjects on the fourth or fifth day, the average value was 1.1 micrograms per liter. If, on the other hand, the participants ate the canned soup, the content not only rose to 20.8 micrograms per liter on average, it was also detectable in every single BPA.

To what extent the results can be generalized cannot yet be said by the scientists? after all, only one group was examined, namely Harvard students and employees, and only canned food from one manufacturer was used. However, they assume that such effects can also be observed with other canned soups with a similar BPA content. It is also difficult to say whether the increase in BPA exposure, which is clearly temporary in this case, has a health effect. The results available so far are simply too different for that? in some cases they are even contradicting one another.

How unclear the study situation on the question of whether or not BPA actually poses a health risk is also shown by the fact that not even the federal authorities come to a uniform assessment. The Federal Institute for Risk Assessment BfR, for example, considers the limit values ​​currently set by the EU to be absolutely sufficient. According to this, a person could ingest an amount of 0.05 milligrams, as 50 micrograms, per kilogram of body weight per day without negative consequences being expected. At 0.03 to 0.07 micrograms per day, the actual exposure is far below this value.

For the Federal Environment Agency UBA, on the other hand, are the 50 micrograms far too high? There are a number of studies that have shown changes in behavior or physical processes even with much smaller amounts, according to the reasoning. The UBA therefore recommends drastically reducing the use of COP and taking targeted precautionary measures to protect particularly vulnerable population groups such as small children. Such a measure has already been implemented: Since the middle of this year, baby bottles containing BPA have no longer been allowed to be sold (for the discussion about BPA, see also Hormon aus der Plastikverkauf, bdw 5/2010, p. 38).

Jenny Carwile (Harvard School of Public Health) et al .: JAMA, vol. 306, p. 2218 © Wissenschaft.de? Ilka Lehnen-Beyel
November 23, 2011

© Wissenschaft.de