Experts Debate Safety of Cannabinoid Nanoemulsions in Food and Beverages

Yet, Wani is not categorical in his support for nanoemulsions. He explains, “It is a matter of great concern to substantiate the safety of nanoparticles before commercializing them on the world food market.”

Wani lists four significant questions regarding the consumption of nanoemulsions:

• Do nanoparticles have free access to cells, or are they controlled in some way?
• How long do nanoparticles remain inside the body?
• How are they excreted?
• Do they have toxic effects?

“These questions are yet to be answered, [primarily] because the research on the safety and toxicity of nanoparticles is still in infancy,” Wani says.

Where There’s Agreement

If it seems as though there are two camps of diametrically opposed scientists debating the issue, there is much about nanoemulsions on which all parties essentially agree. The first factor everyone agrees on is that nanoemulsions and nanoparticles are an emerging technology we do not yet fully understand. This lack of a complete understanding opens up serious questions about nanoemulsion safety, to which even an enthusiastic nanoemulsion supporter like Dr. Douglass yields.

In particular, Dr. Douglass identifies the issue of surfactant ingredients, which lower surface tension, as a source of concern. “When it comes to food, there are fewer surfactants that have been judged to be GRAS for food use. There are so many types of surfactants—for example, polysorbate, polysorbate 80 tween—these were developed for the pharmaceutical industry. Some have applicability for food use, but some people have concerns. Are they [too effective as] surfactants, where they start to bypass the intestinal barrier?”

There are several concerns about surfactants, Dr. Douglass says. In some cases, surfactant ingredients may be classified as GRAS in some quantities, but not in others, and he worries that inexperienced formulators and regulators might not know to hold to the quantity limits. Likewise, he worries that the same inexperienced formulators or regulators might employ or allow ingredients that have only been classified as GRAS for pharmaceutical use, but not for food use.

There’s also the problem that not everyone agrees about GRAS designation. For some surfactant ingredients, the decision to designate them GRAS has been less than unanimous, and some maintain concerns about the safety of those ingredients.

This issue “refers to the gaps in toxicological understanding,” Dr. Douglass says. “If they’re GRAS for food-use, they should be fine. But since the risk of hazard is never zero, these potentially could have some deleterious effect that escapes current toxicological understanding.”

At this point, Dr. Douglass’ position begins to align with that of Dr. White, who highlights the lack of understanding of how nanoparticles are digested.

“For organic nanoemulsions like those that are used for delivering cannabinoids,” says Dr. White, “the concern is that little is known about the absorption or toxicity of the nanoparticles themselves. Cannabinoids, including CBD, are pharmacologically active ingredients. There is no way to know the health risks or effects of combining nanotechnology and cannabinoids unless diligent toxicology study is conducted.”

The possibility remains that nanoparticles could be absorbed into different regions of the gastrointestinal tract, says Dr. McClements, though he adds that he doesn’t believe there is evidence to support this theory.

“A particle that’s small enough can go around your cells—paracellular transport. That’s somewhat of a concern, at least a conceptual concern, with nanoparticles,” Dr. Douglass says. “With emulsions, the idea is that you can disrupt that bilayer of the cells and make it more permeable to things it would normally keep out.”

Yet, Dr. Douglass sees this concern as “mainly theoretical” in situations where all ingredients are designated GRAS for food use. Like Dr. McClements, he says there has been no “demonstrable concern from data sampling.”

Lack of Evidence

This doesn’t mean that Dr. Douglass presumes the safety of GRAS nanoemulsions to be settled. He notes that GRAS designations change, and some ingredients designated as GRAS have been removed from the list after they have become better understood. “But, generally there’s a pretty good foundation to say there’s probably an acceptable hazard or risk profile in using these ingredients,” he adds.