Olfactory Science Low on the Leaderboard

And Team USA is not exactly killing it

Music, fashion and fragrance are driven by popular trends. A new style arrives out of nowhere and can become the Hot New Thing overnight. Scientific research is not immune to fads, but it works on a longer timeline and is driven by what scientists think is fundable, publishable, or likely to lead to promotion. Scientific trends can be tracked over time by looking at how many papers are published on a given topic. This is easily done with the search functions on the National Institutes of Health’s PubMed website.

Here, for example, are recent trends for some high profile public health issues.

HIV, now treatable and no longer fatal, remains a major research topic. Studies on diabetes have been on a steady rise, while those on COVID surged and fell back.

What happens when we search PubMed for “human olfaction”?

The answer is “not much.” There were about 1,200 publications a year until 2020 and 2021 when things took off (the blue line). But once you substract COVID-related smell publications (orange line) the count drops back down. Temporary or permanent reductions in smell ability were common in the early strains of COVID and this drove a lot of work on olfaction. In later strains, smell impairment became a less frequent and less severe symptom and the publication rate dropped off. In the end, this burst of studies yielded few insights into the mechanisms of flu-based smell loss or how to prevent it. They did, however, prove to be a rich source of shoddy science: more than 650 COVID papers have been retracted so far.

We can zoom in on more specific topics, such as perception and production of body odor. A search for papers on “human axillary odor” published in 2024 and 2025 returned a total of 29. Most of these (nearly all from China) were about surgical and/or pharmaceutical interventions for osmidrosis (stinky armpits). That leaves ten relevant papers from a variety of countries:

Sheep recognizing human emotional odors (France)

Female ovulatory phase odors with positive effects in males (Japan)

A new technique for sampling human axillary odor (France)

Enzymes behind axillary smell (France)

Genetics and axillary microbiome (USA)

Dogs detecting COVID in humans by odor (Tunisia)

Ovulatory shifts in axillary odor (Germany)

More on sheep recognizing human emotional odors (France)

Chemical detection of thiols in human axillary odor (UK)

Women’s emotional and hormonal response to male BO (Russia)

All interesting research. But what leaps out for me is that only one of these studies was by American researchers. (Go Gators!—Ed.)

Let’s look at another specific topic: “odor production and perception in human infants.” A PubMed search for 2024 and 2025 produced 67 results of which 29 were relevant. Only 10% of these studies (3/29) were by American researchers. There were six papers from Germany, four from Turkey (!), and two from France. The US is barely a player in this area.

Over the same time period there were eight papers on “human odor perception and Alzheimer’s disease.” Four of them were American studies. That’s a good percentage but a tiny number considering the potential impact of AD on the aging U.S. population.

Thirty-five years after Linda Buck and Richard Axel discovered the mammalian odor receptors, olfactory science has lost its zip. There remains much to explore about the chemical, biological, cognitive, social, and emotional basis of smell in humans. Yet only a meager amount of work is being done. And Europeans are doing more of it than Americans. Are American scientists simply uninterested in olfaction? Do U.S. funding agencies have other priorities? Is it an insufficiently chic topic? I wish I knew the answer.