*COUGH* *COUGH* *COUGH*
I heard you coughing just now…
I always have a cherry cough drop in my cherry lunchbox but after hearing (-- actually reading) what I have to say, would you still take this cough drop? The common ingredient that is emphasized in a cough drop is menthol. At your local drugstore, you’d see that plastered on different cough drop brands.
Thermoreceptors detect temperature but there are certain channels that can detect temperature AND pain. That receptor is TRPM8 and when activated, it triggers sodium channels to open and the sensory neurons (nocioreceptors) to depolarize, which reduces the pain sensation. The cooling effect comes from activating the thermoreceptor. It’s like getting a sprained ankle and icing it to feel relief but in this case, you are “icing your throat.” But when applying ice on our skin, we get a numbing sensation when it’s too cold which indicates that our skin temperature has changed. When we consume menthol, the temperature in our body does not change, it’s an illusion since our thermoreceptors are activated.
Now, don’t go and take many cough drops to feel the cooling sensation. As everyone knows, too much of something may also be bad for you. There was a case study in India who was diagnosed with menthol poisoning after ingesting peppermint oil. The lethal dose for menthol is around 50-150mg while one cough drop contains 5-10mg (Kumar et al., 2016). Though one may be interested and say that cough drops are yummy, overconsumption of cough drops are not advised.
Also, let’s say that your cough is caused by a certain disease. Well, cough drops alter the severity of the cough (Johnson et al., 2018), so if you see a provider, make sure to mention that you did take a cough drop. Menthol may increase one’s cough threshold and decrease in cough reflex sensitivity (Wise et al. 2023). So yes, menthol does give you temporary relief but depending on the severity of your cough, it may worsen your symptoms and conditions.
So would you pass on this cough drop or would you like to take this cough drop and trick your brain to think that everything is “cool”?
Johnson, D., Mead, R., Kennelty, K., & Hahn, D. (2018). Menthol Cough Drops: Cause for Concern?. Journal of the American Board of Family Medicine : JABFM, 31(2), 183–191. https://doi.org/10.3122/jabfm.2018.02.170363’
Kumar, A., Baitha, U., Aggarwal, P., & Jamshed, N. (2016). A fatal case of menthol poisoning. International journal of applied & basic medical research, 6(2), 137–139. https://doi.org/10.4103/2229-516X.179015
Wise, P. M., Breslin, P. A., & Dalton, P. (2012). Sweet taste and menthol increase cough reflex thresholds. Pulmonary pharmacology & therapeutics, 25(3), 236–241. https://doi.org/10.1016/j.pupt.2012.03.005
Hi Rachel! Great blog post.
ReplyDeleteTo be fair, I am scared of cough drops for the risk getting a cavity. HAHA! So usually when I do have a persistent cough, I'll take ZzzQuil or some other medication that would make me go to sleep, so I don't have to deal with the cough. This may not be ideal, but 'they' do say that sleep is the best medicine. Who is 'they'? I don't really know. Learning about how a cough drop works on a molecular level was very interesting. I wonder what else is just an 'illusion' that we take to help our body's recovery. Has this research swayed you from taking cough drops?
I love that you brought up your cherry lunchbox because it is honestly such an iconic part of you and it made this post even more entertaining to read. What I really enjoyed was how you took something as simple as a cough drop and turned it into a mini physiology deep dive. The way you explained TRPM8 activation and how menthol changes sodium channel behavior made the cooling sensation make so much more sense. It is interesting that what feels like a temperature change is really just our neurons being tricked into firing differently. Your reminder about not overusing cough drops was also surprisingly important, because people tend to think “harmless” means unlimited. This post did a great job blending everyday experience with real physiological mechanisms, and it definitely made me look at something as ordinary as a cough drop in a completely different way. But let’s be honest, if my throat hurts I am absolutely caving.
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