The Bundesinstitut für Risikobewertung (BfR, German Institute for Risk Assessment)) has issued a warning that meals prepared in uncoated aluminium menu trays may contain high levels of aluminium. Right or wrong?
From my point of view – wrong. Here the BfR has approached the issue from completely the wrong direction, using not the coated aluminium trays that are specifically available and recommended for acidic foodstuffs, but instead has deliberately used uncoated trays, thus arriving at a result that is ultimately irrelevant.
Has the BfR deliberately tested an inappropriate form of use and ignored the warnings printed on the products?
Yes, this is my firm impression. They even confirm this in their publication, which states that the trays that the BfR used in these tests bore a warning that they should not be used for acidic foodstuffs. For the tests, the BfR filled the trays with strongly acidic foodstuffs all the same, so it’s not surprising that they found high concentrations of aluminium in the foods.
But it is conceivable that in stressful situations – in a school canteen, for example – people may overlook the warnings on the aluminium trays: is their improper use not a distinct possibility?
I can’t exclude the possibility that such materials are improperly used in individual cases, but you can’t simply declare that such mistakes are an everyday occurrence like the BfR does. For this to happen would mean that all the professionals and experts who are properly trained in working in institutional canteens ignore the warnings and don’t make proper use of the knowledge they have. That’s wrong in my opinion.
So, do the BfR’s measurement results apply only under very improbable circum-stances?
They reflect a very, very unusual exceptional case and as such can’t be extrapolated to the normal conditions under which German consumers prepare their meals.
To what extent?
The tests are based on the assumption is that the aluminium trays – the venyl trays, which are not coated – are used in the wrong way, improperly. That’s one aspect. The other is that strongly acidic foods are prepared in a cook-and-chill process and then must be kept warm for a further two hours. This keep-warm stage is very important for the transfer of aluminium, since this is the only stage where aluminium is actually released. And, what’s more, these factors must all occur at one and the same time to achieve aluminium results as high as the ones that the BfR measured.
How realistic is the scenario used in the BfR test in practice?
On the one hand for the very reason that the materials must be improperly handled to achieve such results, on the other also regarding the test foods that the BfR chose for their tests, which don’t match up to reality. All the foods they used were highly acidic ones, none of which are actually ingredients of ready-to-cook convenience meals that must be kept warm. Let’s take just sauerkraut juice as an example – that’s a beverage that you don’t prepare in an aluminium tray, but simply drink from a glass – and usually without heating it either. The same goes for apple puree. First, you don’t dilute apple puree the way the BfR did it, and second, you eat it as a dessert, as a cold dessert, and not as part of a convenience meal that is kept warm for two hours. The same goes for pureed tomatoes – they’re not a typical ingredient of convenience meals, but instead they’re prepared separately, together with other ingredients that raise the pH considerably and thus also increase the dissolved aluminium that this ingredient produces. This criticism applies throughout – they chose only foodstuffs that are very strong solvents of aluminium, resulting in much higher levels of aluminium that is the case with the ingredients typically used in convenience meals.
Are you accusing the BfR testers of deliberately choosing test foods to yield results that are as poor as possible?
That’s right, that’s what I’m saying. While it’s right to map out the so-called worst case in tests of this kind, this worst case must still be within the borders of the realistic. It can’t drift off into the unrealistic, and this is exactly what’s happened in this case.
Not ony supermarket customers and consumers who buy convenience meals in alu-minium trays, but also caterers and other institutional users and canteens are now highly unsettled by this report. What would you like to tell these people?
I’d tell these people – first and foremost those who take their meals in community catering institutions, old people’s homes, residents of retirement homes, people who eat in canteens, children who eat in school canteens – that they can all trust in getting meals prepared by experts, by trained personnel and cooks and nutritional specialists who are aware of their responsibility and do their job properly. These people do not prepare acidic food in bare aluminium trays and keep the food warm in such trays, but instead use suitable, coated aluminium trays. All those consumers who buy their food in the supermarket, for example convenience meals that are packed in aluminium trays, can also take comfort in the fact that the industry that makes such food uses the right packaging materials and thus takes the proper precautions to prevent aluminium from finding its way into the food in significant quantities.
What’s the situation regarding the use of aluminium grilling trays to cook food on barbecues?
Here too, there’s no question of risks when using grilling trays made of aluminium as long as acidic food and ingredients are not put on them. The use of such grilling trays can even make a major contribution to protecting people’s health, since such trays help prevent the formation of polycyclic aromatic hydrocarbons, which form when fat drips directly onto the hot coals. To this extent, grilling trays of this kind are very, very helpful culinary utensils
What more can you tell us to help us understand the problems with aluminium and the ways in which aluminium finds its way into food?
Highly acidic foods react with the surface of the aluminium material – more exactly, the acid in these foods starts to dissolve the exposed aluminium. This dissolved aluminium can naturally be taken up into the food and then into the body when the food is eaten. For most people, such an uptake of aluminium is completely harmless, since the metal is excreted again in the normal digestive process. Only a very few people with predisposing illnesses actually enrich the aluminium they take up with their food in their body. And as a measure to protect these people, the European Food Safety Authority, EFSA, has set limits for a tolerable weekly uptake. This limit is generally hardly ever reached – presumably not even by people who consume convenience meals prepared in aluminium trays, since the amount of aluminium that goes over into the food is relatively low in the realistic setting.
Which other sources of aluminium are there for the human body?
One important aspect to remember when talking about the topic of aluminium is that this metal predominantly comes from entirely natural sources. Much of the food we consume contains relatively high amounts of aluminium – for instance tea and chocolate – and many of the mineral and natural waters we drink also contain high concentrations of aluminium, which are thus the sources of by far most of the aluminium we ingest. Only a very small proportion – about three to four per cent of the aluminium we take up – comes from packaging materials and similar sources.
What should consumers bear in mind to be on the safe side?
Consumers who use uncoated aluminium materials in their household – for example foils or trays – should take care not to use them in connection with acidic foods. As a rule, these precautions are printed on the packaging of the products. What counts as acidic food? That’s easy to tell, without any laboratory or chemicals, simply by using your sense of taste. There are plenty of foods that taste sour – for example fruit, marinated meat, salad sauces, but also slices of tomato or lemon, of course. These react with the surface, and accordingly should not be cooked in such uncoated materials. If you use coated aluminium utensils, on the other hand, there‘s no problem whatsoever, even when you’re preparing meals using ingredients of this kind.
And so, how do you sum up the results of the BfR’s tests?
They’ve completely missed the mark, is what I’d say. And they’ve caused plenty of confusion by setting up a test scenario that’s a long way from reality and accordingly doesn’t give us any real impression of how much aluminium we actually take up with our food.