They’re already in our toothpaste and some packaged foods, writes Stephanie Osfield, but little is known about their effects on our health.
As scientists cook up ways to improve the taste of food with microscopic ingredients called nanoparticles, some say they’re playing with fire.
Yet living in the modern world brings us all into daily contact with these particles. They may sound straight out of a sci-fi blockbuster, but they’ve already been introduced into a wide range of products such as food, paint, plastics, sunscreen and even tennis rackets. So how do they work? And how safe are they? Here are 10 things you need to know about them.
1. They’re miniscule
To help you get the picture, a human hair is 10,000 times wider than a nanoparticle. In science speak, nanoparticles measure less than 100 nanometres and as one nanometre is a billionth of a metre, a nanoparticle is the size of a molecule.
2. Already in our food
Nanoparticles occur naturally in foods in the form of nanoscale sugars, amino acids, peptides and proteins. However, man-made nanoparticles, such as titanium dioxide and silica, have recently been found in Australian food. Titanium dioxide is a whitening agent used in products as wide-ranging as chewing gum and toothpaste. Nano silica is an anti-caking agent that helps to prevent clumping and is found in supplements and tablets as well as in icing sugar, powdered soups and milks, packet spices and sauces. Some scientists say man-made nanoparticles may not be as safe as nature's own.
3. Food labelling loophole
No law requires manmade nanoparticles to be listed on food labels. Food Standards Australia New Zealand believes that those particles already in Australian food are completely safe. “FSANZ and other international food regulatory agencies have not identified any health effects associated with the use of nanoparticles, such as titanium dioxide and silica, following their ingestion in food,” says Lorraine Haase at FSANZ.
4. Step into the unknown
Most food safety tests don’t measure nanoparticles and because it’s such a new area of science no large-scale studies have produced conclusive results on their health effects. Lung damage is one area of concern. Chinese researchers have shown that a class of nanoparticle being developed in medicine has caused lung damage in mice.
5. Organ infiltration
“There are concerns that nanoparticles could infiltrate our organs, tissues and cells, disrupting DNA and damaging the mitochondria, the powerhouse of our cells,” says Professor Thomas Faunce, at the College of Medicine, Biology and Environment at the Australian National University, where he has been researching nanoparticles and public health. “Does this mean nanotechnology is contributing to the rise in autoimmune disease or autism? We simply don’t know,” says Professor Faunce. “That’s why nanotechnology needs to be listed on food labels, so people can make informed choices — particularly if they have health issues such as chronic disease or food sensitivity.”
6. The jury is still out
Hard evidence is expected to be released in Australia soon. The federal government is waiting for the results of a toxicology report into the effects of the two most common food nanoparticles — food additives titanium dioxide and silica.
7. Food chain doubts
Nanoparticles may be entering the food chain through agricultural products. Companies around the world are starting to use nanoparticles in cattle and poultry feed, and also in pesticides. So far no extensive studies on farming methods have determined whether these particles are entering the food chain.
8. Better nano-nutrition
Meanwhile, nanotechnology in food could be used to boost our nutrition. Scientists are toying with wrapping vitamins and minerals in nano-coatings, so that they withstand the stomach’s powerful digestive acids allowing them to be better absorbed in the intestine.
9. Helpful diet aids
One day nanoparticles may help us cut our fat, salt and sugar intake. If these ingredients could be coated onto a food’s surface in nano-sized particles, less could be used to achieve the same taste result (a bit like spreading butter more thinly).
10. Tomorrow’s world
In the future, it seems there will be more nanoparticles in food ingredients and packaging. Even though they’re not used widely in Australia, in America they are found in cheeses, sweet biscuits, doughnuts, chocolate syrup, yoghurt, mayonnaise and salad dressing. Nanoparticles are also used to minimise bacterial growth in socks and washing machines.
We will keep you posted as more findings come to light on this cutting edge of food technology.