Oranges make me sweat. You? Know why?

January 25, 2008 6:32 PM

Oranges make me sweat. You? Know why?

It's pretty simple: biting into a tart orange causes my face to break out into sweating almost immediately. The sweating sticks around for a minute or two and dissipates. Just smelling fresh orange smell can elicit the response. Lime and lemon don't seem to do it, but then again I'm not eating as much of those.

Does this happen to you? Do you have any idea why this happens?

posted by a robot made out of meat to food & drink (12 comments total)

It's possible that you might have diabetes mellitus. Have you had your blood sugar levels checked lately?
posted by peacheater at 6:43 PM on January 25

Actually, yes, I have been screened for diabetes (normal fasting glucose) in the past year.
posted by a robot made out of meat at 7:08 PM on January 25

It could be an allergic reaction.
posted by amyms at 7:30 PM on January 25

It might have something to do with the tartness. Sour Patch Kids make me sweat, too; most stuff that's really sour or tart does. I have no idea why, though.
posted by jesourie at 7:33 PM on January 25

It's called "gustatory sweating." The old-school name for it is Frey syndrome. None of the articles I found by Google™ing were very good, but this one is decent and written in layman's terms.
posted by ikkyu2 at 8:03 PM on January 25 [3 favorites]

I have a friend with MS who reports to me that eating oranges or smelling oranges dramatically increases the intensity of a phenomenon that often happens to her anyway since she was diagnosed: she will have an unrelated smell sensation when she is eating some food, such as an intense burning leaves odor when she is eating vanilla ice cream, or an unrelated taste sensation when she is smelling something, such as the taste of beef stroganoff when she smells lavender (my made up examples, I'm sorry to say). I used an orange based solvent (Citra-solv) to clean some greasy bicycle parts over a period of an hour one night without using gloves, and the next morning, I had so much trouble moving my fingers independently on my right hand it was hard to make coffee.

MS causes lesions in the fatty myelin insulation sheathes on nerves, and this can cause crosstalk between nerve fibers, which I think is why my friend tastes strange things when she smells things and vice versa, and I would say that the volatile oils of orange peels increase the level of that crosstalk, probably by partly further dissolving the fatty myelin or by dissolving into it and making it more conductive than it should be.

So increased cross talk is what I would attribute my friend's sensations to, as well as my difficulty controlling my fingers-- and your tendency to sweat when you eat an orange, too.

Ikkyu2's link says that what happens to you very often happens much more markedly to people who have their parotid gland removed because the severed nerves which used to supply the parotid gland retarget themselves to sweat glands on the cheek. This might mean that the nerves which normally go to to those sweat glands are in the same bundle as the nerves to the parotid gland and near them, but I'm not sure.

In any case, I'd say you are experiencing nerve crosstalk, enhanced by orange oils, between your salivary glands and the sweat glands on your cheeks. However, the mere smell of oranges from across the room would not seem to be sufficient to cause a lot of crosstalk, so if I want to save my explanation, I must resort to some kind of Pavlovian conditioning, generalized to your sweat glands on earlier occasions when there was enough orange oil for actual crosstalk.
posted by jamjam at 9:26 PM on January 25 [1 favorite]

jamjam, you're a little off the rails here. The common factor in Frey syndrome between diabetes and parotidectomy is damage and subsequent repair/reinnervation of parasympathetic autonomic nerves known as visceral efferents. The course of these hitchhiking visceral efferent fibers is rather circuitous, and in this case it's not cross-talk - instead the nerves were damaged, died back, and then regenerated in the wrong direction, reaching the face instead of the parotid gland.

A related phenomenon is "crocodile tears", increased lacrimation when eating.
posted by ikkyu2 at 9:53 PM on January 25

ikkyu2: the problems with the Frey syndrome story are a) just oranges; not other foods which make me salivate. I'm salivating right now thinking of bananas flambe over good vanilla ice cream. b) I have no trauma to my face, other neuropathy, or reason to have neuropathy. Recent exam has vibration, pinprick, and proprioception intact. Reflexes 2+ throughout. My friends are doing physical diagnosis now, so I've had about 10 cranial nerve and neuro exams lately.
posted by a robot made out of meat at 6:58 AM on January 26

You're right, ikkyu2, I was off the rails-- that 'circuitous' link you provided offers a much better and more plausible explanation: the facial nerve passes right through the parotid gland. When a robot made out of meat eats or smells oranges, then, a transient swelling of the parotid gland as it loads up and starts pumping out the saliva could be pressing on the facial nerve directly, causing the sweating.

The problem with this explanation, which seems to me to explain gustatory sweating in general quite nicely, is that it is only oranges, not other foods which produce salivation, that cause this effect in a robot made out of meat, so the explanation must be supplemented at least, perhaps either by something that oranges do to that nerve chemically (as I was attempting above), or by some argument involving conditioning or memory.
posted by jamjam at 8:25 AM on January 26

Ketchup always makes my nose sweat. Has done so since I was a toddler (30-some years ago). No explanation; never could figure out why. Just the skin on my nose (bridge & sides) decides to moisten itself. I don't think any other foods cause this. I have no allergies, no diabetes, no gland problems, and can eat any other tomato-y or vinegar-y foods with no issues. Until recently I thought everyone had the same experience. Now I just brush it off as one of those oddments that makes individuals so diverse & interesting. So, no -- you're not wierd or about to die from some horrible disease. Unless I am too. :-)
posted by cuddles.mcsnuggy at 8:57 AM on January 26

It would be interesting to know if the sweating occurs mainly on one side; if impingement on a nerve is part of the chain of causation, sweating seems unlikely to be bilaterally symmetric.
posted by jamjam at 9:38 AM on January 26

nope, bilateral.
posted by a robot made out of meat at 3:28 PM on January 26