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Sure, tech can induce sense of smell in healthy people, but where’s the benefit?

Electrical stimulation in the nose induces sense of smell in human subjects

Our Review Summary

The news release focuses on a recent paper regarding the use of electrodes in the nose to stimulate the brain and produce a sense of smell. The release is careful to highlight that this is only the earliest stage of research into developing a technology that might be able to restore a sense of smell to people with “smell loss” or anosmia — specifically for those who have lost the sense of smell due to nerve damage. The release misses the mark in describing benefits, harms and sources of funding.


Why This Matters

Proof-of-concept studies are interesting and important because they raise awareness of new possibilities. For people suffering from anosmia, the potential — however remote — for a technology that addresses their condition would be interesting indeed. But it’s important to highlight the limitations of such proof-of-concept research. This release doesn’t oversell the discovery, which is good. But if a condition is caused by nerve damage, and a prospective technological treatment involves attaching electrodes to what may be the relevant damaged nerves, one wonders just how much a study can tell you when it looks only at people whose nerves are not, in fact, damaged.


Does the news release adequately discuss the costs of the intervention?

Not Applicable

Cost isn’t addressed, but we wouldn’t expect much here in regard to cost. The work is far too preliminary to attach a price tag, and the release highlights just how far off any relevant technology is from becoming a reality. Ideally, some discussion of cost, even in the most general terms (even if, for example, it were simply to say that it is far too early to estimate cost) would have been desirable.

Does the news release adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

The release suggests that this is a “breakthrough for human patients.”  None of the participants (incorrectly referred to as patients) in the study had lost their sense of smell, so none could have their sense of smell restored. The release notes that three of the five participants who underwent the experiment reported sensations of smell when their nerves were stimulated by electrodes. Importantly, the release neglects any qualification or description of the sensations.  The manuscript notes the smells as “onion like,” ” fruity but bad,” “antiseptic like” and “sour.”  Yes, electrical stimulation did create smells but creating de novo smells is hardly a benefit.  Indeed the sensation of smells where none are present is referred to as olfactory hallucination.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

As with cost, it is far too early to create a laundry list of potential side effects associated with nerve stimulation to induce sensations of smell. However, there are things that could be said. For example, the study itself found that volunteers reported discomfort and occasional pain associated with the electrode stimulation. And the potential for inducing olfactory hallucination needs to be considered.  Dysosmia may be less desirable than anosmia.

Does the news release seem to grasp the quality of the evidence?


The release notes the small sample size (five people), that all five participants had an intact sense of smell, and that only three of the people reported sensations of smell stemming from the electrode stimulation. That’s enough to earn it a satisfactory rating here. However, as noted above, it fails to answer what would appear to be a threshold question. If the work is held up as a proof of concept meriting additional research for the potential development of a prosthetic sense of smell; AND the proof of concept was done by using electrodes on nerves in a person’s nose; AND all of the volunteers in the proof-of-concept study had healthy nerves in their nose; BUT the people any prosthetic could be used on are people with nerve damage; then what, if anything, does this study tell us? Would the proof of concept even work in patients whose anosmia is caused by nerve damage? That seems like a fundamental question that needs to be answered before even exploring the feasibility of developing relevant technology, and it’s not addressed here.

Does the news release commit disease-mongering?


The release describes the potential effects of anosmia fairly accurately, consistent with a 2013 study on the consequences of the condition. It also puts the disease in context, describing how many people are estimated to be affected by smell loss.

Does the news release identify funding sources & disclose conflicts of interest?

Not Satisfactory

The release does not mention any sources of funding or potential conflicts of interest. To be clear, even if the work was internally funded and there are no conflicts of interest, that is worth noting. The release acknowledges previous work of “research colleagues” at the Virginia Commonwealth University but should have gone further in explaining that the researchers hold a patent for an olfactory implant system and have formed a company to develop the technology.

Does the news release compare the new approach with existing alternatives?


The release notes that some cases of anosmia can be treated, but that there are no proven therapies for treating anosmia cases caused by nerve damage. The release also mentions preliminary work being done at another university aimed at developing a treatment for patients with anosmia caused by nerve damage (that work is also in its earliest stages). That earns it a satisfactory rating here.

Does the news release establish the availability of the treatment/test/product/procedure?


The release makes clear that a tremendous amount of work needs to be done before any relevant treatment technology might become available.

Does the news release establish the true novelty of the approach?


The release makes clear that the researchers have, “for the first time, induced a sense of smell in humans by using electrodes in the nose to stimulate nerves in the olfactory bulb.” What they have not done, however, is shown whether that’s relevant for patients whose sense of smell is caused by nerve damage.

Does the news release include unjustifiable, sensational language, including in the quotes of researchers?

Not Satisfactory

The use of the word “breakthrough” is out of place in a summary of proof of concept work.

Total Score: 5 of 9 Satisfactory


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