Health Concerns Grow Over Tiny Particles Being Added to Food
Deep inside food and food packaging is a microscopic universe where tiny nanoparticles reside. These nanoparticles are intended to help keep food fresh or improve its taste or its color. But could these additives also be causing harm to human health?
The prefix “nano-” means one billionth when used as a unit of measure, but can also just mean small —very, very small. A nanoparticle measures anywhere between 1 nanometer (nm) and 100nm. For the sake of comparison, a piece of paper is 100,000nm thick.
Nanomaterials have been widely used in industries ranging from medicine to engineering, but they are increasingly being applied in food processing and packaging too. Some nanoparticles are used to prevent the passage of oxygen, carbon dioxide, or moisture, and thereby extend shelf life and inhibit the spread of bacteria in foods. The benefit to the consumer is healthier, safer, and higher quality foods.
But as with any relatively new technology, the full health impacts are still uncertain. And that’s got some people worried.
What Types of Nanoparticles Are There?
Nanoparticles can be divided into two categories: organic nanoparticles, which are composed primarily of carbon-containing molecules such as proteins, lipids and carbohydrates, and inorganic nanoparticles consisting primarily of molecules that do not contain carbon, such as silver, titanium dioxide, and zinc oxide.
In some foods, nanoparticles are naturally occurring. For instance, milk contains casein micelles, nano-sized spherical structures that automatically assemble from casein proteins. The structure and chemical properties of the micelles enable casein proteins to dissolve in milk, and facilitates absorption into the human gut.
[N]anoparticles may be added to foods to enhance certain properties such as flavor, shelf life, and color. For example, a common nanoparticle called titanium dioxide—which is found in sunscreens, plastics, and paint—is used to brighten foods like sauces and cheeses.
In other cases, nanoparticles may be added to foods to enhance certain properties such as flavor, shelf life, and color. For example, a common nanoparticle called titanium dioxide—which is found in sunscreens, plastics, and paint—is used to brighten foods like sauces and cheeses.
Are Health Concerns Justified?
The health impacts of nanoparticles on the body— particularly the digestive tract—are still largely unknown. Some studies on animals in which abnormally high quantities of nanoparticles were used, have shown they can get into the bloodstream and accumulate in the body.
These studies showed inflammation and adverse impacts on liver, kidney, and brain following high dosages of silver nanoparticles, as well as damage to the hearts of young rats by high dosage of titanium dioxide nanoparticles.
But studies into health impacts of nanoparticle consumption have shown different results due to the wide range of variables involved such as composition, structure, size, dose and what they are consumed with. One review article by the University of Massachusetts noted that, “nanoparticles are already present in many natural and processed foods, and that new kinds of nanoparticles may be utilized as functional ingredients by the food industry in the future. Many of these nanoparticles are unlikely to have adverse effects on human health, but there is evidence that some of them could have harmful effects and that future studies are required.” And an earlier study carried out at Dong-A University in South Korea found “no significant accumulation” by rats which had ingested them, suggesting that most of it was eliminated through feces.
Studying The Latest Science
But the need for further investigation has prompted new studies to be carried out. Dr. Helen Onyeaka, an industrial microbiologist at the University of Birmingham in the UK, led one such study. Her team has been looking into the safety of nanomaterials in food production and packaging, and one of the things which piqued their interest was the sheer amount of inquiries being generated into its safety by the public, regulatory bodies, and scientific community.
They conducted a comprehensive review of existing literature on nanotechnology in food packaging, while also examining research papers and reports to gain a wide-ranging picture.
Dr. Onyeaka said in an interview with The Earth & I: “We discovered that nanomaterials can improve food packaging, providing benefits like enhanced barrier properties and long shelf life.
“However, we discovered nanoparticles can migrate from packing into food, which is a concern that raises the question about their safety.”
The team also discovered that the size of the nanoparticles influenced their behavior, with smaller ones having a higher likelihood of migrating into food. However, overall, the transfer of nanomaterials into food was limited.
She added: “Given the unique properties of nanoparticles, it wasn’t surprising that they could migrate into food, but the extent of migration and potential health impacts are areas that need further study.”
Is There a Need For Regulation?
Fortunately, studies have yet to show widespread or serious health impacts from nanoparticles that are commonly used in food and packaging. And with studies still being carried out into possible health impacts, regulation of nanomaterials in food is rarely mandated. Yet some countries have taken precautionary measures.
With studies still being carried out into possible health impacts, regulation of nanomaterials in food is rarely mandated. >
In France, reporting of substances with nanoparticles has been mandatory since 2013 and requires manufacturers, importers, and distributors of more than 100 grams of nanoparticle substances per year to declare the identity of the substances, the quantities handled, and the intended uses.
In 2020 France banned the use of one nanoparticle—titanium dioxide—with the European Union following suit last year. The UK, however, did not follow the EU in banning titanium dioxide, with its Food Standards Agency stating that it was not able to identify any safety concerns after reviewing the data.
The EU also issues guidance to industry regarding the use of nanomaterials, with the introduction of a nanomaterial definition, which will be the same for chemicals, novel food, cosmetics, biocides and medical devices.
Further Research and Funding
Dr. Onyeaka believes many people are worried about the possible effects of nanoparticles, but that there are also those who think that they can be used safely as long as proper regulation is in place.
She said additional research can help resolve such concerns.
“While there is growing awareness of the potential benefits of nanotechnology in food applications, there is also concern about the safety and regulatory aspects” she said.
“The level of understanding is still evolving, and ongoing research is essential to provide a more comprehensive assessment of the risks and benefits.”
She added that assessing these long-term effects requires continuous observation to detect potential health impacts that may not be immediately apparent but could surface over extended periods.
“Nanotechnology is constantly evolving, introducing new types of nanomaterials and applications that necessitate ongoing safety assessments to keep up with these developments.”
She said: “Nanotechnology is constantly evolving, introducing new types of nanomaterials and applications that necessitate ongoing safety assessments to keep up with these developments.
“Reaching a scientific consensus on the safety of nanomaterials in food is a gradual process that demands more studies and data to form a comprehensive understanding.”
She added that funding was also a crucial factor, but that it was also essential to coordinate efforts among researchers, regulatory agencies, and industry stakeholders to address pressing questions effectively.
Food for thought
With pressures on global food prices and supplies, the use of technology to preserve food shelf life has potentially huge benefits. But as with any nascent technology, the science may advance faster than the understanding of the long-term consequences. So, as recommended by Dr. Onyeaka, continued investigation in nanoparticles may be needed to protect the health of consumers.
*Mark Smith is a journalist and author from the UK. He has written on subjects ranging from business and technology to world affairs, history, and popular culture for the Guardian, BBC, Telegraph, and magazines in the United States, Europe, and Southeast Asia.
For the Earth & I, Mark Smith spoke with Dr. Helen Onyeaka.