Are there nanoparticles in your supplement drinks?
Researchers from Arizona State University studied several dietary supplement drinks, to detect possible metallic nanomaterials.
Their results showed that the presence of nanomaterials could affect the morphology of human intestinal cells.
Moreover, some nanomaterials could also be released into wastewaters, raising concerns about the long term effects on the environment.
Nanomaterials (NMs) are particles which have at least one dimension in the order of nanometers (nm, 10-9 m), usually smaller than 100 nm. An example can be nanoparticles, with a nanometric diameter.
Due to their small size, NMs may have properties which can be very different from those of the bulk material, and which may be heavily affected by their size (i.e. the value of the particle diameter).
Because of their particular properties, NMs are widely employed in many different sectors and used in various commercial products; these include electronics, medicine, and energy storage.
Nanomaterials and Food Processing
Food processing also employs NMs, for different purposes. Manufacturers can use nanomaterials, for instance, in food packaging, to incorporate antibacterial agents, and/or control the gas permeability; this could help reduce food spoilage and extend food shelf life.
Manufacturers can also add nanomaterials directly to the food, for nutrient delivery, to avoid oxidation, or to improve food texture.
Although science has proven these benefits, there are increasing concerns about the possible side effects NMs could have on human health. Because of this, many scientists from different areas are investigating the extent of nanomaterial presence in food items, and their possible interactions with the human body.
Study on NMs in Dietary Supplement Drinks
In this context, an interesting study was carried out by scientists from Arizona State University (Tempe, US), as they investigated the presence of nanomaterials in commercial dietary supplement drinks. They also tried to simulate the behavior which such NMs can have on human intestinal cells.
They published the results of this study in the journal Sustainable Chemistry & Engineering in June 2014.
Researchers of this study chose 8 representative drinks; each one of these contained, according to the label, a different metal (gold, silver, copper, zinc, iridium, palladium, platinum or silicon). They analyzed these drinks to check if the metal contained was present in the form of nanomaterials.
Their results showed that NMs were indeed present in all drinks, although their concentration was different depending on the drink and the metal; the whole concentration range was 1-100 mg/L. The size and the shape of the NMs were also different, depending on the metal; gold, for instance, was present in form of regular nanoparticles while zinc NMs had a more irregular shape.
Nanomaterials and Intestinal Cells
Dr. Robert Reed, one of the scientists involved in the research, explains to Decoded Science more details of the study. To try to understand the effects the NMs can have on human intestines, Dr. Reed and his coworkers used some cells (Caco-2) which closely mimic the behavior of human intestinal cells.
“We used these cells as they have some parts – microvilli – which extend out of the cells and give them additional surface area. The same happens in our intestine and this helps the digestion.” Dr. Reed said.
“After the addition of the supplement drinks to the cells, we saw disruptions in the microvilli structure; some microvilli, for instance, clumped together.
The effect was comparable for all metals we tested and, although it was not lethal, it could potentially effect the digestion.
We cannot be sure that the same thing could happen in the gut of a human body after drinking these products; as you can imagine, this would a very difficult thing to test and monitor. Our experiment, however, was a first step in trying to understand the potential interactions of NMs after human ingestions.”
Releasing Nanomaterials into the Environment?
These NMs are not metabolized by the human organism; therefore, eventually they are excreted and end up in wastewaters. Dr. Reed and coworkers studied whether the treatment plants currently used today could remove these nanomaterials from the wastewater, or whether they would be released in the environment.
They saw that for metals such as iridium, palladium and silicon, the fraction absorbed during the wastewater treatment was relatively low (less than 40 %); this means that substantial amounts of nanomaterials could be discharged in the environment. At present nobody knows what could be the long term effects of this.
Nanomaterials in Supplements: Not Good News
Although using nanomaterials in supplements may seem to be a good idea, research shows that not only could they affect our ability to properly digest food, but they will also reach the environment, with unknown results. According to Dr. Reed: “These data are not conclusive, but can give us a first idea about NMs-intestine interaction and after-excretion behavior.”
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