Fantastic. Now we're going to see more of those toxic aerosol air freshener machines everywhere. They use petroleum solvents as a carrier and sensitize people toward becoming allergic.<p>Those fan-propelled oil droplets of air wick are also bad. They are toxic, but due to their oily nature, they soak into every single porous surface. You know how cat piss is impossible to get out? It is the same with these too.<p>We are also not allowed to know what the ingredients are either. It is a trade secret labelled as "fragrance". Could be leftover chemicals from deepwater horizon for all you know.
> Funding: This work was supported by Procter and Gamble<p>Not bash the researchers or the quality of their research but I'm unsure if a negative result would have been acceptable to their continued funding. I'm sure P&G would like to use this research to sell their diffusers after all.
This study mananaged to finance 38 participants worth of MRI time and (likely significant) monetary compensation for all 132 participants. Yet it wastes no more than a couple of sentences on how it threw out 109 participants' worth of data on cognitive tests, resulting in a drop out rate of 83% for the cognitive side of things, and still considers its findings in this area valid.<p>(section 2.5 - Impact of COVID-19 pandemic)<p>The discussion similarly does not waste the reader's time on possible validity issues or confounders.<p>I can only speculate that more scientific rigour would have been applied had it been grant money being thrown around.
On the other hand, I'm allergic to most fragrances (itchy eyes, running nose, stuffed up sinus). I have to hold my breath while almost running through the perfume department on the ground floor of a department store. I cannot walk down certain aisles of my grocery store (cleaning supplies, detergents, soaps). I dread staying at higher-end hotels because they spray their perfume everywhere. The smell of laundry detergents and fabric softeners makes me sick. Same with most dishwashing soaps. The deodorizers in Uber/Lyft cars can be terrible. The fragrance at the Denver airport bathrooms is so overpowering, I have to hold my breath while I'm in there, and then gasp through my mouth before running out.<p>I don't remember fragrances being so terrible when I was younger. But maybe it's another case of "it was better in the old days".
> Male and female older adults (N = 43), age 60–85, were enrolled in the study and randomly assigned to an Olfactory Enriched or Control group. Individuals in the enriched group were exposed to 7 different odorants a week, one per night, for 2 h, using an odorant diffuser<p>> A statistically significant 226% improvement was observed in the enriched group compared to the control group on the Rey Auditory Verbal Learning Test and improved functioning was observed in the left uncinate fasciculus, as assessed by mean diffusivity<p>> 7 essential oil odorants (rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender; from The Essential Oil Company, Portland, OR)
I really wish I could take results like this at face value like I once did, but after the ongoing reproducibility crisis, I am very skeptical.<p>Olfactory sensation decreases dramatically with age, so even if I bracket the above concern, there's just not a lot of prima facie credibility here. At best, it looks like a placebo effect.<p>Can we all just stop popularizing, awarding tenure, and making public policy on the basis of results which haven't been reproduced yet? I.E. wait until there really <i>is</i> a scientific conclusion?
Hah, nice. A long while back I was interested in building a diffuser system that would rotate between different oils throughout the week. The idea at the time was that each new scent would act as a memory anchor of sorts to reflect back upon. That way when I smell the smell in the future, I'd be flooded with memories of the days that smell was present. Never did it, but it was a fun thought experiment.
As a lifelong (congenital) anosmic, I often think about the practical consequences of lacking that sense. A whole therapeutic avenue cut off, if I'm thinking about this correctly, is a new one.
This makes me think of observations re: functioning in adults with hearing loss (tl;dr hearing aids help mitigate cognitive decline).<p>Maybe it's simply that remaining stimulated is critical to sustaining cognitive resilience, such that odors - much like any other sensory stimulant - help keep your mind on its toes?<p>Fun to think about