Nanotechnology's Benefits and Risks for Dietary Supplements

March 30, 2011

No Small Thing: the benefits of nanotechnology are great-but so are the risks.

Once in a generation, a new technology is developed that is truly disruptive-that is, having the potential to displace standard practices and offering a quantum leap forward to those willing to implement it. The disruptive technology for this generation is nanotechnology and represents as great a change as did genetic engineering or the quick-freeze process for frozen food developed by Clarence Birdseye. However, unlike these aforementioned technologies, nanotechnology has a relatively low financial threshold of implementation, making it available to smaller, less-well-capitalized manufacturers.

Nanotechnology is defined as the manufacture and use of particles of 100 nanometers in at least one dimension. (A nanometer, or nm, is one-millionth of a millimeter). Some very specific advantages may conferred by the use of nano-sized particles (also known as nanoengineered materials, or NEM). These advantages may include rapid and more complete absorption from the gastrointestinal tract, thus allowing for use of less ingredient, and some nano-sized particles even have access to body compartments or activities not accessible by conventional-sized particles of the same substance.

The end goal of some nanoengineered materials may also be enhanced by the use of coatings or particle charge that can prolong the life of the substance in the body by avoiding excretion or engulfment by white blood cells. Other applications are less obvious, but nonetheless represent significant advantages. Applications include creating lipid micelles for suspension of particles in a water-in-oil or oil-in-water medium, without the use of emulsifiers; or the protection of labile substances in hostile environments such as the highly acidic stomach or the enzyme- and surfactant-rich upper intestine, thus allowing protected particles to be absorbed, rather than destroyed. A partial list of nanoengineered materials used in food is available at the Woodrow Wilson Institute for Emerging Technology.(1) At this point, however, it looks as if most nanoengineered-material technological advances are being made in food container materials to preserve freshness and thwart bacteriological decomposition.

What makes nanoparticles so unique? Conventional-sized particles (greater than 100 nm) obey conventional Newtonian physics, in which the individual atoms of a molecule or element act as a whole. In contrast, nanoparticles tend to obey the laws of quantum physics because their surface-to-mass ratio is so much greater-and with individual atoms closer to the surface, these individual atoms exercise much more influence on the behavior of the substance, often conferring physical properties much different than a conventional-sized particle. Differences include particle charge, melting point, solubility, surface tension, and many other characteristics that are normally thought of as immutable. Such changes are as radical as copper becoming an insulator or gold changing color (to blue or red) at nano-size dimensions. In short, at the nano-dimension, many new behaviors and thus new applications are possible for substances whose properties were previously thought to be known and fully exploited.

However, when substances are reduced to nano size to take advantage of these new physical characteristics, thought must be given to the effect on the recipient biological species. It is logical that if the physical characteristics are changed enough to elicit different behavior in the chemical medium, different behaviors may be seen in humans or animals consuming these nanotech wunderkinds. These effects may include an inability to excrete some substances, which can build up to toxic levels in the body or gain access to areas of the body normally protected because conventionally sized particles are excluded. An example of this is gaining passage through the placenta to the fetus, where a nanomaterial may act to produce birth defects.

Despite the fact that biological consequences may well also arise in the use of NEM, many people believe that once a substance has been approved for use in food, it makes no difference if the form to be used is in a conventional format or a nanoengineered material. Furthermore, some believe FDA has no authority to regulate nanomaterials. Nothing could be further from the truth.

In 2006, legal scholar Michael Taylor wrote an article published by the Woodrow Wilson Institute entitled, “Regulating the Products of Nanotechnology: Does FDA Have the Tools It Needs?”(2) In this article, Taylor concluded that there are in fact many FDA regulations conferring appropriate authority to the agency, to be exercised if needed.

Also in 2006, FDA formed its Nanotechnology Task Force, which issued its report in July of 2007.(3) Because nanotechnology was in its relative infancy at the time of the Task Force report, no specific regulations or guidelines were promulgated as there had been for genetically modified materials. Possibly because of this lack of guidelines, a February 2010 U.S. Government Accountability Office report was very critical of FDA for not putting more emphasis on nanoengineered materials produced for food use.(4)

Probably in response to this critical report, when FDA reopened comments for the GRAS notification process in the December 28, 2010, Federal Register, a new emphasis was placed on physical characterization of particles proposed for use in food. This provision is a direct and obvious attempt to throw a net around any substance utilizing nanoengineered technology. In any event, the fact that Taylor, the author of the article describing FDA authority in this area of nanotechnology, is now Deputy Commissioner of Foods at FDA-a position that would include human and animal foods/feeds and dietary supplements-is a strong indicator that nanoengineered materials will be regulated by FDA.

There is no doubt that nanotechology is a disruptive technology and will likely change our current thinking on ingredient use on its head. However, while we savor the possibilities of new characteristics and new applications, we must also keep in mind that these same new characteristics may elicit new and untoward biological responses when ingested by consumers. Probably at the seat of FDA’s concerns about nanotechnology is the low capitalization requirement for implementation of the use of nanotechnology, as well as the concomitant absence of adequate safety assessment and subsequent high probability of adverse reactions. Thus, nanotechnology, for all its potential advantages, also embodies a high potential for abuse and harm to the consumer.