Olfactory Training, Better
Loss of smell (anosmia) is associated with COVID and aging, but it could also be an early sign of neurodegenerative diseases like Alzheimer’s or Parkinson’s.
Anosmia, by any other name…
The loss of the sense of smell (anosmia) is these days well-associated with COVID and Long-COVID, but also can simply come with age:
National Institute of Aging | How Smell & Taste Change With Age
…although it can also be something else entirely:
❝Another possibility is a problem with part of the nervous system responsible for smell.
Some studies have suggested that loss of smell could be an early sign of a neurodegenerative disease, such as Alzheimer’s or Parkinson’s disease.
However, a recent study of 1,430 people (average age about 80) showed that 76% of people with anosmia had normal cognitive function at the study’s end.❞
Read more: Harvard Health | Is it normal to lose my sense of smell as I age?
We’d love to look at and cite the paper that they cite, but they didn’t actually provide a source. We did find some others, though:
❝Olfactory capacity declines with aging, but increasing evidence shows that smell dysfunction is one of the early signs of prodromal neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease.
The loss of smell is considered a clinical sign of early-stage disease and a marker of the disease’s progression and cognitive impairment.❞
Read more: Neurons, Nose, and Neurodegenerative Diseases: Olfactory Function and Cognitive Impairment
What’s clear is the association; what’s not clear is whether one worsens the other, and what causal role each might play. However, the researchers conclude that both ways are possible, including when there is another, third, underlying potential causal factor:
❝Ongoing studies on COVID-19 anosmia could reveal new molecular aspects unexplored in olfactory impairments due to neurodegenerative diseases, shedding a light on the validity of smell test predictivity of cognitive dementia.
The neuroepithelium might become a new translational research target (Neurons, Nose, and Neurodegenerative diseases) to investigate alternative approaches for intranasal therapy and the treatment of brain disorders. ❞
~ Ibid.
Another study explored the possible mechanisms of action, and found…
❝Olfactory impairment was significantly associated with increased likelihoods of MCI, amnestic MCI, and non-amnestic MCI.
In the subsamples, anosmia was significantly associated with higher plasma total tau and NfL concentrations, smaller hippocampal and entorhinal cortex volumes, and greater WMH volume, and marginally with lower AD-signature cortical thickness.
These results suggest that cerebral neurodegenerative and microvascular lesions are common neuropathologies linking anosmia with MCI in older adults❞
- MCI = Mild Cognitive Impairment
- NfL = Neurofilament Light [Chain]
- WMH = White Matter Hyperintensity
- AD =Alzheimer’s Disease
Read more: Anosmia, mild cognitive impairment, and biomarkers of brain aging in older adults
How to act on this information
You may be wondering, “this is fascinating and maybe even a little bit frightening, but how is this Saturday’s Life Hacks?”
We wanted to set up the “why” before getting to the “how”, because with a big enough “why”, it’s much easier to find the motivation to act on the “how”.
Test yourself
Or more conveniently, you and a partner/friend/relative can test each other.
Simply do like a “blind taste testing”, but for smell. Ideally these will be a range of simple and complex odors, and commercially available smell test kits will provide these, if you don’t want to make do with random items from your kitchen.
If you’d like to use a clinical diagnostic tool, you can check out:
Clinical assessment of patients with smell and taste disorders
…and especially, this really handy diagnostic flowchart:
Algorithm of evaluation of a patient who has olfactory loss
Train yourself
“Olfactory training” has been the got-to for helping people to regain their sense of smell after losing it due to COVID.
In simple terms, this means simply trying to smell things that “should” have a distinctive odor, and gradually working up one’s repertoire of what one can smell.
You can get some great tips here:
AbScent | Useful Insights Into Smell Training
Hack your training
An extra trick was researched deeply in a recent study which found that multisensory integration helped a) initially regain the ability to smell things and b) maintain that ability later without the cross-sensory input.
What that means: you will more likely be able to smell lemon while viewing the color yellow, and most likely of all to be able to smell lemon while actually holding and looking at a slice of lemon. Having done this, you’re more likely to be able to smell (and distinguish) the odor of lemon later in a blind smell test.
In other words: with this method, you may be able to cut out many months of frustration of trying and failing to smell something, and skip straight to the “re-adding specific smells to my brain’s olfactory database” bit.
Read the study: Olfactory training: effects of multisensory integration, attention towards odors and physical activity
Or if you prefer, here’s a pop-science article based on that:
One in twenty people has no sense of smell—here’s how they might get it back
Take care!
Share This Post
Learn To Grow
Sign up for weekly gardening tips, product reviews and discounts.
-
Stop Cancer 20 Years Ago
Dr. Jenn Simmons shares vital tips on preventing cancer and inflammation, advocating for lifestyle changes and proactive health management at any age.
Get Abreast And Keep Abreast
This is Dr. Jenn Simmons. Her specialization is integrative oncology, as she—then a breast cancer surgeon—got breast cancer, decided the system wasn’t nearly as good from the patients’ side of things as from the doctors’ side, and took to educate herself, and now others, on how things can be better.
What does she want us to know?
Start now
If you have breast cancer, the best time to start adjusting your lifestyle might be 20 years ago, but the second-best time is now. We realize our readers with breast cancer (or a history thereof) probably have indeed started already—all strength to you.
What this means for those of us without breast cancer (or a history therof) is: start now
Even if you don’t have a genetic risk factor, even if there’s no history of it in your family, there’s just no reason not to start now.
Start what, you ask? Taking away its roots. And how?
Inflammation as the root of cancer
To oversimplify: cancer occurs because an accidentally immortal cell replicates and replicates and replicates and takes any nearby resources to keep on going. While science doesn’t know all the details of how this happens, it is a factor of genetic mutation (itself a normal process, without which evolution would be impossible), something which in turn is accelerated by damage to the DNA. The damage to the DNA? That occurs (often as not) as a result of cellular oxidation. Cellular oxidation is far from the only genotoxic thing out there, and a lot of non-food “this thing causes cancer” warnings are usually about other kinds of genotoxicity. But cellular oxidation is a big one, and it’s one that we can fight vigorously with our lifestyle.
Because cellular oxidation and inflammation go hand-in-hand, reducing one tends to reduce the other. That’s why so often you’ll see in our Research Review Monday features, a line that goes something like:
“and now for those things that usually come together: antioxidant, anti-inflammatory, anticancer, and anti-aging”
So, fight inflammation now, and have a reduced risk of a lot of other woes later.
See: How to Prevent (or Reduce) Inflammation
Don’t settle for “normal”
People are told, correctly but not always helpfully, such things as:
- It’s normal to have less energy at your age
- It’s normal to have a weaker immune system at your age
- It’s normal to be at a higher risk of diabetes, heart disease, etc
…and many more. And these things are true! But that doesn’t mean we have to settle for them.
We can be all the way over on the healthy end of the distribution curve. We can do that!
(so can everyone else, given sufficient opportunity and resources, because health is not a zero-sum game)
If we’re going to get a cancer diagnosis, then our 60s are the decade where we’re most likely to get it. Earlier than that and the risk is extant but lower; later than that and technically the risk increases, but we probably got it already in our 60s.
So, if we be younger than 60, then now’s a good time to prepare to hit the ground running when we get there. And if we missed that chance, then again, the second-best time is now:
See: Focusing On Health In Our Sixties
Fast to live
Of course, anything can happen to anyone at any age (alas), but this is about the benefits of living a fasting lifestyle—that is to say, not just fasting for a 4-week health kick or something, but making it one’s “new normal” and just continuing it for life.
This doesn’t mean “never eat”, of course, but it does mean “practice intermittent fasting, if you can”—something that Dr. Simmons strongly advocates.
See: Intermittent Fasting: We Sort The Science From The Hype
While this calls back to the previous “fight inflammation”, it deserves its own mention here as a very specific way of fighting it.
It’s never too late
All of the advices that go before a cancer diagnosis, continue to stand afterwards too. There is no point of “well, I already have cancer, so what’s the harm in…?”
The harm in it after a diagnosis will be the same as the harm before. When it comes to lifestyle, preventing a cancer and preventing it from spreading are very much the same thing, which is also the same as shrinking it. Basically, if it’s anticancer, it’s anticancer, no matter whether it’s before, during, or after.
Dr. Simmons has seen too many patients get a diagnosis, and place their lives squarely in the hands of doctors, when doctors can only do so much.
Instead, Dr. Simmons recommends taking charge of your health as best you are able, today and onwards, no matter what. And that means two things:
- Knowing stuff
- Doing stuff
So it becomes our responsibility (and our lifeline) to educate ourselves, and take action accordingly.
Want to know more?
We recently reviewed her book, and heartily recommend it:
The Smart Woman’s Guide to Breast Cancer – by Dr. Jenn Simmons
Enjoy!