Cathy2 wrote:Do you have any idea how much once must ingest to get this level of reaction from your body?
Anecdotal evidence suggests only extreme amounts of the hottest peppers affect hearing. Let's see how that fits with some quick-and-dirty calculations...
Capsaicin's effects on outer hair cells seem to be exerted in the concentration range of micromoles per liter. In the Wu et al paper, capsaicin was used at 300 μM, a concentration with near maximal effect, I think; somewhat different experiments reported in an earlier paper used 20 μM, but I'm not sure what the lower limit is. A quick look at the chile literature (
Canto-Flick et al, 2008) shows that some of the hottest habaneros contain 60 milligrams capsaicin per gram of dry chile weight (these chiles register about 900,000 Scoville units). The molecular weight of capsaicin is 305 g/mol, so that makes it 0.2 mmol capsaicin per dry gram. The average North American weighs about 80 kg, about 60% (50 kg) of which is water. So, if you were to uniformly dissolve the capsaicin from 25 g (nearly 1 ounce) of dried super-hot habaneros in a 50 liter sack of water, that's 5 mmol per 50 liters = 0.1 mM = 100 μM.
Obviously there are enough baseless assumptions and unknowns (eg, how efficiently is capsaicin absorbed? is capsaicin concentrated in or excluded from the inner ear?) so as to make such calculations nearly worthless, but achieving micromolar-range capsaicin concentrations in the human body, and perhaps in the inner ear, doesn't seem out of the question.
Cathy2 wrote:Could a person more sensitive to capsaicin have this reaction at a much lower level of consumption?
The main point of the Wu et al paper is that capsaicin's effect on the outer hair cells is not mediated through the capsaicin receptor (which does mediate the "hot" response when eating chiles). For that reason, I wouldn't expect an individual who's especially sensitive to heat in chiles to necessarily be especially susceptible to capsaicin's effect on hearing. It's a complex system, though, and I'm getting pretty far outside my scientific comfort zone. Even with that disclaimer, I feel quite confident saying you're unlikely to go deaf if you happen to accidentally get a small piece of bird's eye chile while eating a Thai meal!
Cinnamon Girl wrote:It was interesting to read about how difficult it is to work with these peppers, which we understand in moderation from our shop experience. When we weigh any of the hot peppers featured in the title of this forum, we take them into the ventilated blending room to weigh them for the customer, so that we don't choke all the other customers. There wast a period of time when we could not get ground habanero chile peppers. We love these hot peppers more than any other because in addition to heat, their fruity flavor shines through. We don't really understand the point of heat without flavor. The man who had done the grinding of the habanero chile peppers at our source, for many, many years, had died. A series of new grinders were hired, who rarely lasted the week. We went almost a year without ground habanero peppers before they eventually found a replacement grinder. We were afraid to ask the details, hopefully they tripled the pay!
Interesting stories! I didn't realize you need to take such precautions with Aleppo and Urfa peppers. I used to get ground habanero (yes, great stuff; I need to stop by for more) from your store and think I remember when it became unavailable. Now I know why. I wonder how the old habanero grinder's hearing was before he died. It may not be possible to inhale enough to affect hearing, but who knows the effects of chronic exposure. Even though they're natural products, in large quantities chiles can have significant pharmacological effects.