Many sweets, especially in South Asia, have decorative Silver or Gold foils placed on them. How safe are those products?
Decorative silver and gold foils
Decorative leaves, called Varq, are very fine sheets of precious metals, such as Silver and Gold. These foils are used for decorative purposes on sweets — typically South Asian sweets — and occasionally, dry fruits and mouth freshener snacks.
The tradition of making decorative leafs goes back by at least 25 centuries. There are references to silver and gold leafs in ancient Ayurvedic (Indian traditional medicine) texts. As per medicinal text books, silver was considered an anti–microbial agent and gold was considered an aphrodisiac.
How are they made?
These foils are made by taking precious metal dust in two polyester sheets, which are coated with some kind of calcium powder. The sheets are pounded for hours, which makes the malleable metal dust to form a very thin foil. Such leaves are said to be 0.2 to 0.8 micron in thickness. So, they can easily break down into pieces, if handled by hand.
Traditionally, instead of the coated polyester sheets, the metal dust was placed between ox, cow, or goat hides. It seems that this animal skin makes it easy for the final foils to be removed. However, the pounding on the hides can technically make the animal tissue mix with the metal foils.
Problems and solutions
Since many religions promote vegetarianism, metal foils which are made using animal skin are taboo. Sweets made with such decorative leaves may have to be classified as non–vegetarian.
However, modern production techniques don’t use animal skin anymore.
Since the foils used to come in contact with animal hide during their production, the sweets made with them were not hygienic. This resulted in a ban for the decorative leaves by the FSSAI (Food Safety and Standards Authority of India) for usage of animal skin in the production in 2016. However, that ban was lifted in 2017 and new safety and hygiene guidelines were issued for the production of the decorative leaves.
Precious metal safety
Since the decorative leaves are eaten with the sweets, there is a concern whether their consumption can cause harm.
Gold is a noble metal and eating it causes no harm.
Silver is a anti–microbial metal. When silver comes in the contact with living cells, silver ions can bind to DNA, RNA, cellular proteins, and enzymes. This can damage and kill the cells. This effect is called Oligodynamic Effect and is still not well understood.
A typical silver foil contains less than half a milligram of silver, which is very small. Also, the metal used is in an inert, and not ionic, form. So, while silver can kill microbial cells, the silver foils are considered safe for human consumption.
Purity and heavy metal contamination
The biggest problem with silver leaves is fake silver or impure silver leaves.
Fake silver leaves: Crooks pass off foils made up of aluminium, which is a toxic substance for consumption.
Impure silver leaves: Silver leaves are required to be of 99.9% purity. On many occasions, the silver used is contaminated with chromium, cadmium, nickel, copper and lead. The impurities can cause safety problems.
While you cannot paint everything with the same brush, such cheating is often seen in low–income, low–education areas.
Decorative silver and gold leafs, and sweets made with them, are safe by themselves for consumption.
If the leafs are made with modern production techniques, animal skins will not be used.
If the silver used in the foils is contaminated with heavy metals, or if aluminium is used surreptitiously in its place, that can cause serious health challenges.
While it is hard to tell the origin of the silver foils, use some discretion; buy or eat sweets only from well–known sources, who have a reputation to protect.
First published on: 4th August, 2016