Is it unhealthy to eat leftover food?

Finally understand: Why you shouldn't keep food in aluminum foil

by Peter Carstens
Aluminum is considered harmful to human health - and yet it can be found everywhere in the kitchen

For decades, sandwiches and leftovers were safely wrapped in aluminum foil and stored. It was also practical, because the wafer-thin film is light and airtight and hugs the contents well.

However, under certain circumstances this can be dangerous. Namely when the foil, the aluminum bowl or the aluminum dishes come into contact with acids or salt for a long time. This is the case, for example, with foods such as applesauce, rhubarb, tomato puree, sauerkraut, pickled herring or pickled cucumbers.

You should never store such food or leftovers in aluminum foil or aluminum dishes. This is because aluminum ions dissolve on contact and migrate into the food.

Menu trays in the criticism

In 2017, the Federal Institute for Risk Assessment examined menu trays made of pure aluminum, such as those used in day-care centers, old people's homes and in out-of-home catering. The result: the longer the food was kept warm, the more aluminum was later found in the food. In some cases, a multiple of what experts see as barely tolerable was released. Anyone who eats food from aluminum menu trays every day runs the risk of ingesting harmful amounts of aluminum.

Aluminum is everywhere

Aluminum is the third most common element in the earth's crust - and we encounter it in everyday life not only in the form of aluminum foil, but also in unprocessed foods and additives. It can also be found in food packaging or in cosmetics such as deodorants.

The metal is practical - but poisonous to humans. Among other things, the element can damage the nervous system and our fertility. It has even been linked to Alzheimer's. (A risk that the Federal Institute for Risk Assessment rules out.) Healthy people excrete aluminum through the kidneys. But people who suffer from kidney failure can accumulate the metal in their body.

Alu-free alternatives

Plastic foil is often just as suitable as aluminum foil for the airtight storage of leftovers. And it's guaranteed to be non-toxic with jars, screw-on jars or storage boxes made of glass or porcelain. You can also do without aluminum meal trays and rather heat the food in a steel saucepan.