…here in the US Northeast for sore throats, whether caused by infection, or simply too dry indoor air. Was thinking about the soothing aspect of hot toddies, and came across a recipe from Emeril Lagasse, in the Food Network website, here:
This recipe got five stars as a treat(meant) for sore throats. However, fact is for me, that I won’t ever try this recipe, because I don’t do alcohol, and I don’t even like the smell of whisk(e)y...
...so I searched some more, and came across this excellent blogpost: in it, Aparna travels to India and back, and finishes with the recipe for a non-alcoholic tea-based hot toddy for sore throats that is also good sipped cold:
What these two recipes share (aside from tea) is the presence of spices that activate both TRPV1, the hot receptor and TRPA1, the cold receptor. For TRPV1, for example, it’s black pepper in Aparna’s alcohol-free version, and alcohol itself in Emeril’s version; and for TRPA1 it’s powdered dried ginger with its shogaols and lemon in Aparna’s recipe, and lemon juice in Emeril’s.
If you sip either of these two drinks, you will first feel a bite of pain, only to feel the pain quickly subside and the soreness in your throat with it.
Why would activation of TRPV1 and TRPA1 together actually be soothing?
To untangle the answer, first a rather unusual experiment where the researchers passed cold dry air across the throats of forty-five healthy (and, I might add, somewhat foolhardy) volunteers to cause a sore throat—the kind of experience we have here in the US Northeast during these cold winter months.*
This treatment led to inflammation. To quote the authors’ paper:
“This study shows that tonic stimulation of the pharyngeal mucosa with cold dry air causes pain, irritation, and discomfort whilst swallowing and an increase of inflammatory mediators, which is reversible.”
The inflammatory markers they measured included substance P. Its levels rose in the throat during cold air treatment, and vanished about 30 minutes after cold treatment was stopped.
Substance P tells pain nerve endings to send pain messages to the brain, and is released with TRPA1 activation by the cold air. Release of substance P in turn leads to release of the other inflammatory mediators, which then leads to the release of more substance P, and so on in a vicious cycle.
When you activate either TRPA1 or TRPV1 alone, the associated nerve endings release substance P. However, when you activate both together, you first get a burst of substance P release, but then the two receptors mutually inhibit—to my simplistic thinking, nature made it difficult to sense both hot and cold at the same time.
Not so simplistically, though, we do know for sure that both receptors can sit on the same cells, and that when both are stimulated simultaneously, they can cancel each other out. **
The ingredients in these hot toddies do just this—that’s why hot toddies can make your throat feel so good!
* Renner B, Ahne G, Grosan E, Kettenmann B, Kobal G, Shephard A. Tonic stimulation of the pharyngeal mucosa causes pain and a reversible increase of inflammatory mediators. Inflammation Research. 2013;62(12):1045-1051. doi:10.1007/s00011-013-0663-7.
** Barry G. Green, Betsy L. McAuliffe. Menthol desensitization of capsaicin irritation: Evidence of a short-term anti-nociceptive effect. Physiology & Behavior 68 (2000) 631–639.
** Takaishi, M., Uchida, K., Suzuki, Y. et al. Reciprocal effects of capsaicin and menthol on thermosensation through regulated activities of TRPV1 and TRPM8. J Physiol Sci (2016) 66: 143. doi:10.1007/s12576-015-0427-y.
Note: menthol activates TRPA1 as well as the cool receptor TRPM8.
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